Updated GNU utilities

35 files changed, 31389 insertions, 0 deletions

diff --git a/gnu/usr.bin/awk/ACKNOWLEDGMENT b/gnu/usr.bin/awk/ACKNOWLEDGMENT
new file mode 100644
index 000000000000..b6c3b0b0c692
--- /dev/null
+++ b/gnu/usr.bin/awk/ACKNOWLEDGMENT
@@ -0,0 +1,21 @@
+The current developers of Gawk would like to thank and acknowledge the
+many people who have contributed to the development through bug reports
+and fixes and suggestions.  Unfortunately, we have not been organized
+enough to keep track of all the names -- for that we apologize.
+
+Another group of people have assisted even more by porting Gawk to new
+platforms and providing a great deal of feedback.  They are:
+
+	Hal Peterson <hrp@pecan.cray.com> (Cray)
+	Pat Rankin <gawk.rankin@EQL.Caltech.Edu> (VMS)
+	Michal Jaegermann <NTOMCZAK@vm.ucs.UAlberta.CA> (Atari, NeXT, DEC 3100)
+	Mike Lijewski <mjlx@eagle.cnsf.cornell.edu> (IBM RS6000)
+	Scott Deifik <scottd@amgen.com> (MSDOS 2.14)
+	Kent Williams (MSDOS 2.11)
+	Conrad Kwok (MSDOS earlier versions)
+	Scott Garfinkle (MSDOS earlier versions)
+
+Last, but far from least, we would like to thank Brian Kernighan who
+has helped to clear up many dark corners of the language and provided a
+restraining touch when we have been overly tempted by "feeping
+creaturism".
diff --git a/gnu/usr.bin/awk/COPYING b/gnu/usr.bin/awk/COPYING
new file mode 100644
index 000000000000..3358a7be862a
--- /dev/null
+++ b/gnu/usr.bin/awk/COPYING
@@ -0,0 +1,340 @@
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+                          675 Mass Ave, Cambridge, MA 02139, USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
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+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
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+refers to any such program or work, and a "work based on the Program"
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+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
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+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
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+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
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+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
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+distribute the same sections as part of a whole which is a work based
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+
+Thus, it is not the intent of this section to claim rights or contest
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+exercise the right to control the distribution of derivative or
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+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
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+
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+    allowed only for noncommercial distribution and only if you
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+
+The source code for a work means the preferred form of the work for
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+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
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+You are not responsible for enforcing compliance by third parties to
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+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
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+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
+
+	Appendix: How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) 19yy  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) 19yy name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.
+
diff --git a/gnu/usr.bin/awk/FUTURES b/gnu/usr.bin/awk/FUTURES
new file mode 100644
index 000000000000..b09656046b27
--- /dev/null
+++ b/gnu/usr.bin/awk/FUTURES
@@ -0,0 +1,120 @@
+This file lists future projects and enhancements for gawk.  Items are listed
+in roughly the order they will be done for a given release.  This file is
+mainly for use by the developers to help keep themselves on track, please
+don't bug us too much about schedules or what all this really means.
+
+For 2.16
+========
+David:
+	Move to autoconf-based configure system.
+
+	Allow RS to be a regexp.
+
+	RT variable to hold text of record terminator
+
+	RECLEN variable for fixed length records
+
+	Feedback alloca.s changes to FSF
+
+	Extensible hashing in memory of awk arrays
+
+	Split() with null string as third arg to split up strings
+
+	Analogously, setting FS="" would split the input record into individual
+	characters.
+
+Arnold:
+	Generalize IGNORECASE
+		any value makes it work, not just numeric non-zero
+		make it apply to *all* string comparisons
+
+	Fix FILENAME to have an initial value of "", not "-"
+
+	Clean up code by isolating system-specific functions in separate files.
+
+	Undertake significant directory reorganization.
+
+	Extensive manual cleanup:
+		Use of texinfo 2.0 features
+		Lots more examples
+		Document all of the above.
+
+In 2.17
+=======
+David:
+
+	Incorporate newer dfa.c and regex.c (go to POSIX regexps)
+
+	Make regex + dfa less dependant on gawk header file includes
+
+	General sub functions:
+		edit(line, pat, sub) and gedit(line, pat, sub)
+	that return the substituted strings and allow \1 etc. in the sub string.
+
+Arnold:
+	DBM storage of awk arrays. Try to allow multiple dbm packages
+
+	? Have strftime() pay attention to the value of ENVIRON["TZ"]
+
+	Additional manual features:
+		Document posix regexps
+		Document use of dbm arrays
+		? Add an error messages section to the manual
+		? A section on where gawk is bounded
+			regex
+			i/o
+			sun fp conversions
+
+For 2.18
+========
+
+Arnold:
+	Add chdir and stat built-in functions.
+
+	Add function pointers as valid variable types.
+
+	Add an `ftw' built-in function that takes a function pointer.
+
+David:
+
+	Do an optimization pass over parse tree?
+
+For 2.19 or later:
+==================
+Add variables similar to C's __FILE__ and __LINE__ for better diagnostics
+from within awk programs.
+
+Add an explicit concatenation operator and assignment version.
+
+? Add a switch statement
+
+Add the ability to seek on an open file and retrieve the current file position.
+
+Add lint checking everywhere, including check for use of builtin vars.
+only in new awk.
+
+"restart" keyword
+
+Add |&
+
+Make 	awk '/foo/' files...	run at egrep speeds
+
+Do a reference card
+
+Allow OFMT to be other than a floating point format.
+
+Allow redefining of builtin functions?
+
+Make it faster and smaller.
+
+For 3.x:
+========
+
+Create a gawk compiler?
+
+Create a gawk-to-C translator? (or C++??)
+
+Provide awk profiling and debugging.
+
+
+
diff --git a/gnu/usr.bin/awk/LIMITATIONS b/gnu/usr.bin/awk/LIMITATIONS
new file mode 100644
index 000000000000..5877197aeb55
--- /dev/null
+++ b/gnu/usr.bin/awk/LIMITATIONS
@@ -0,0 +1,14 @@
+This file describes limits of gawk on a Unix system (although it
+is variable even then).  Non-Unix systems may have other limits.
+
+# of fields in a record:  MAX_INT
+Length of input record:  MAX_INT 
+Length of output record:  unlimited
+Size of a field:  MAX_INT 
+Size of a printf string:  MAX_INT 
+Size of a literal string:  MAX_INT 
+Characters in a character class:  2^(# of bits per byte)
+# of file redirections:  unlimited
+# of pipe redirections:  min(# of processes per user, # of open files)
+double-precision floating point
+Length of source line:  unlimited
diff --git a/gnu/usr.bin/awk/Makefile b/gnu/usr.bin/awk/Makefile
new file mode 100644
index 000000000000..fdca82c4482e
--- /dev/null
+++ b/gnu/usr.bin/awk/Makefile
@@ -0,0 +1,13 @@
+PROG=		awk
+SRCS=		main.c eval.c builtin.c msg.c iop.c io.c field.c array.c \
+		node.c version.c re.c awk.c regex.c dfa.c \
+		getopt.c getopt1.c
+CFLAGS+=	-DGAWK
+LDADD=		-lm
+DPADD=		${LIBM}
+CLEANFILES+=	awk.c y.tab.h
+
+MAN1=		awk.0
+
+.include <bsd.prog.mk>
+.include "../../usr.bin/Makefile.inc"
diff --git a/gnu/usr.bin/awk/NEWS b/gnu/usr.bin/awk/NEWS
new file mode 100644
index 000000000000..6711373d6ea5
--- /dev/null
+++ b/gnu/usr.bin/awk/NEWS
@@ -0,0 +1,1295 @@
+Changes from 2.15.1 to 2.15.2
+---------------------------
+
+Additions to the FUTURES file.
+
+Document undefined order of output when using both standard output
+  and /dev/stdout or any of the /dev output files that gawk emulates in
+  the absence of OS support.
+
+Clean up the distribution generation in Makefile.in:  the info files are
+  now included, the distributed files are marked read-only and patched
+  distributions are now unpacked in a directory named with the patch level.
+
+
+Changes from 2.15 to 2.15.1
+---------------------------
+
+Close stdout and stderr before all redirections on program exit.  This allows
+  detection of write errors and also fixes the messages test on Solaris 2.x.
+
+Removed YYMAXDEPTH define in awk.y which was limiting the parser stack depth.
+
+Changes to config/bsd44, Makefile.bsd44 and configure to bring it into line
+  with the BSD4.4 release.
+
+Changed Makefile to use prefix, exec_prefix, bindir etc.
+
+make install now installs info files.
+
+make install now sets permissions on installed files.
+
+Make targets added:  uninstall, distclean, mostlyclean and realclean.
+
+Added config.h to cleaner and clobber make targets.
+
+Changes to config/{hpux8x,sysv3,sysv4,ultrix41} to deal with alloca().
+
+Change to getopt.h for portability.
+
+Added more special cases to the getpgrp() call.
+
+Added README.ibmrt-aos and config/ibmrt-aos.
+
+Changes from 2.14 to 2.15
+---------------------------
+
+Command-line source can now be mixed with library functions.
+
+ARGIND variable tracks index in ARGV of FILENAME.
+
+GNU style long options in addition to short options.
+
+Plan 9 style special files interpreted by gawk:
+        /dev/pid
+        /dev/ppid
+        /dev/pgrpid
+        /dev/user
+                $1 = getuid
+                $2 = geteuid
+                $3 = getgid
+                $4 = getegid
+                $5 ... $NF = getgroups if supported
+
+ERRNO variable contains error string if getline or close fails.
+
+Very old options -a and -e have gone away.
+
+Inftest has been removed from the default target in test/Makefile -- the
+  results were too machine specific and resulted in too many false alarms.
+
+A README.amiga has been added.
+
+The "too many arguments supplied for format string" warning message is only
+  in effect under the lint option.
+
+Code improvements in dfa.c.
+
+Fixed all reported bugs:
+
+	Writes are checked for failure (such as full filesystem).
+
+	Stopped (at least some) runaway error messages.
+
+	gsub(/^/, "x") does the right thing for $0 of 0, 1, or more length.
+
+	close() on a command being piped to a getline now works properly.
+
+	The input record will no longer be freed upon an explicit close()
+	of the input file.
+
+	A NUL character in FS now works.
+
+	In a substitute, \\& now means a literal backslash followed by what
+	was matched.
+
+	Integer overflow of substring length in substr() is caught.
+
+	An input record without a newline termination is handled properly.
+
+	In io.c, check is against only EMFILE so that system file table
+	  is not filled.
+
+	Renamed all files with names longer than 14 characters.
+
+	Escaped characters in regular expressions were being lost when 
+	  IGNORECASE was used.
+
+	Long source lines were not being handled properly.
+
+	Sourcefiles that ended in a tab but no newline were bombing.
+
+	Patterns that could match zero characters in split() were not working
+	  properly.
+
+	The parsedebug option was not working.
+
+	The grammar was being a bit too lenient, allowing some very dubious
+	  programs to pass.
+
+	Compilation with DEBUG defined now works.
+
+	A variable read in with getline was not being treated as a potential
+	  number.
+
+	Array subscripts were not always of string type.
+
+
+Changes from 2.13.2 to 2.14
+---------------------------
+
+Updated manual!
+
+Added "next file" to skip efficiently to the next input file.
+
+Fixed potential of overflowing buffer in do_sprintf().
+
+Plugged small memory leak in sub_common().
+
+EOF on a redirect is now "sticky" -- it can only be cleared by close()ing
+  the pipe or file.
+
+Now works if used via a #! /bin/gawk line at the top of an executable file
+  when that line ends with whitespace.
+
+Added some checks to the grammar to catch redefinition of builtin functions.
+  This could eventually be the basis for an extension to allow redefining
+  functions, but in the mean time it's a good error catching facility.
+
+Negative integer exponents now work.
+
+Modified do_system() to make sure it had a non-null string to be passed
+  to system(3). Thus, system("") will flush any pending output but not go
+  through the overhead of forking an un-needed shell.
+
+A fix to floating point comparisons so that NaNs compare right on IEEE systems.
+
+Added code to make sure we're not opening directories for reading and such.
+
+Added code to do better diagnoses of weird or null file names.
+
+Allow continue outside of a loop, unless in strict posix mode.  Lint option
+  will issue warning.
+
+New missing/strftime.c.  There has been one chage that affects gawk.  Posix
+  now defines a %V conversion so the vms conversion has been changed to %v.
+  If this version is used with gawk -Wlint and they use %V in a call to
+  strftime, they'll get a warning.
+
+Error messages now conform to GNU standard (I hope).
+
+Changed comparisons to conform to the  description found in the file POSIX.
+  This is inconsistent with the current POSIX draft, but that is broken.
+  Hopefully the final POSIX standard will conform to this version.
+  (Alas, this will have to wait for 1003.2b, which will be a revision to
+  the 1003.2 standard.  That standard has been frozen with the broken
+  comparison rules.)
+
+The length of a string was a short and now is a size_t.
+
+Updated VMS help.
+
+Added quite a few new tests to the test suite and deleted many due to lack of
+  written releases.  Test output is only removed if it is identical to the
+  "good" output.
+
+Fixed a couple of bugs for reference to $0 when $0 is "" -- particularly in
+  a BEGIN block.
+
+Fixed premature freeing in construct "$0 = $0".
+
+Removed the call to wait_any() in gawk_popen(), since on at least some systems,
+  if gawk's input was from a pipe, the predecssor process in the pipe was a
+  child of gawk and this caused a deadlock.
+
+Regexp can (once again) match a newline, if given explicitly.
+
+nextopen() makes sure file name is null terminated.
+
+Fixed VMS pipe simulation.  Improved VMS I/O performance.
+
+Catch . used in variable names.
+
+Fixed bug in getline without redirect from a file -- it was quitting after the
+  first EOF, rather than trying the next file.
+
+Fixed bug in treatment of backslash at the end of a string -- it was bombing
+  rather than doing something sensible.  It is not clear what this should mean,
+  but for now I issue a warning and take it as a literal backslash.
+
+Moved setting of regexp syntax to before the option parsing in main(), to
+  handle things like -v FS='[.,;]'
+
+Fixed bug when NF is set by user -- fields_arr must be expanded if necessary
+  and "new" fields must be initialized.
+
+Fixed several bugs in [g]sub() for no match found or the match is 0-length.
+
+Fixed bug where in gsub() a pattern anchorred at the beginning would still
+  substitute throughout the string.
+
+make test does not assume the . is in PATH.
+
+Fixed bug when a field beyond the end of the record was requested after
+  $0 was altered (directly or indirectly).
+
+Fixed bug for assignment to field beyond end of record -- the assigned value
+  was not found on subsequent reference to that field.
+
+Fixed bug for FS a regexp and it matches at the end of a record.
+
+Fixed memory leak for an array local to a function.
+
+Fixed hanging of pipe redirection to getline
+
+Fixed coredump on access to $0 inside BEGIN block.
+
+Fixed treatment of RS = "".  It now parses the fields correctly and strips
+  leading whitspace from a record if FS is a space.
+
+Fixed faking of /dev/stdin.
+
+Fixed problem with x += x
+
+Use of scalar as array and vice versa is now detected.
+
+IGNORECASE now obeyed for FS (even if FS is a single alphabetic character).
+
+Switch to GPL version 2.
+
+Renamed awk.tab.c to awktab.c for MSDOS and VMS tar programs.
+
+Renamed this file (CHANGES) to NEWS.
+
+Use fmod() instead of modf() and provide FMOD_MISSING #define to undo
+  this change.
+
+Correct the volatile declarations in eval.c.
+
+Avoid errant closing of the file descriptors for stdin, stdout and stderr.
+
+Be more flexible about where semi-colons can occur in programs.
+
+Check for write errors on all output, not just on close().
+
+Eliminate the need for missing/{strtol.c,vprintf.c}.
+
+Use GNU getopt and eliminate missing/getopt.c.
+
+More "lint" checking.
+
+
+Changes from 2.13.1 to 2.13.2
+-----------------------------
+
+Toward conformity with GNU standards, configure is a link to mkconf, the latter
+  to disappear in the next major release.
+
+Update to config/bsd43.
+
+Added config/apollo, config/msc60, config/cray2-50, config/interactive2.2
+
+sgi33.cc added for compilation using cc ratther than gcc.
+
+Ultrix41 now propagates to config.h properly -- as part of a general
+  mechanism in configure for kludges -- #define anything from a config file
+  just gets tacked onto the end of config.h -- to be used sparingly.
+
+Got rid of an unnecessary and troublesome declaration of vprintf().
+
+Small improvement in locality of error messages.
+
+Try to diagnose use of array as scalar and vice versa -- to be improved in
+  the future.
+
+Fix for last bug fix for Cray division code--sigh.
+
+More changes to test suite to explicitly use sh.  Also get rid of 
+  a few generated files.
+
+Fixed off-by-one bug in string concatenation code.
+
+Fix for use of array that is passed in from a previous function parameter.
+  Addition to test suite for above.
+
+A number of changes associated with changing NF and access to fields
+  beyond the end of the current record.
+
+Change to missing/memcmp.c to avoid seg. fault on zero length input.
+
+Updates to test suite (including some inadvertently left out of the last patch)
+  to invoke sh explicitly (rather than rely on #!/bin/sh) and remove some
+  junk files.  test/chem/good updated to correspond to bug fixes.
+
+Changes from 2.13.0 to 2.13.1
+-----------------------------
+
+More configs and PORTS.
+
+Fixed bug wherein a simple division produced an erroneous FPE, caused by
+  the Cray division workaround -- that code is now #ifdef'd only for
+  Cray *and* fixed.
+
+Fixed bug in modulus implementation -- it was very close to the above
+  code, so I noticed it.
+
+Fixed portability problem with limits.h in missing.c
+
+Fixed portability problem with tzname and daylight -- define TZNAME_MISSING
+  if strftime() is missing and tzname is also.
+
+Better support for Latin-1 character set.
+
+Fixed portability problem in test Makefile.
+
+Updated PROBLEMS file.
+
+=============================== gawk-2.13 released =========================
+Changes from 2.12.42 to 2.12.43
+-------------------------------
+
+Typo in awk.y
+
+Fixed up strftime.3 and added doc. for %V.
+
+Changes from 2.12.41 to 2.12.42
+-------------------------------
+
+Fixed bug in devopen() -- if you had write permission in /dev,
+  it would just create /dev/stdout etc.!!
+
+Final (?) VMS update.
+
+Make NeXT use GFMT_WORKAROUND
+
+Fixed bug in sub_common() for substitute on zero-length match.  Improved the
+  code a bit while I was at it.
+
+Fixed grammar so that $i++ parses as ($i)++
+
+Put support/* back in the distribution (didn't I already do this?!)
+
+Changes from 2.12.40 to 2.12.41
+-------------------------------
+
+VMS workaround for broken %g format.
+
+Changes from 2.12.39 to 2.12.40
+-------------------------------
+
+Minor man page update.
+
+Fixed latent bug in redirect().
+
+Changes from 2.12.38 to 2.12.39
+-------------------------------
+
+Updates to test suite -- remove dependence on changing gawk.1 man page.
+
+Changes from 2.12.37 to 2.12.38
+-------------------------------
+
+Fixed bug in use of *= without whitespace following.
+
+VMS update.
+
+Updates to man page.
+
+Option handling updates in main.c
+
+test/manyfiles redone and added to bigtest.
+
+Fixed latent (on Sun) bug in handling of save_fs.
+
+Changes from 2.12.36 to 2.12.37
+-------------------------------
+
+Update REL in Makefile-dist.  Incorporate test suite into main distribution.
+
+Minor fix in regtest.
+
+Changes from 2.12.35 to 2.12.36
+-------------------------------
+
+Release takes on dual personality -- 2.12.36 and 2.13.0 -- any further
+  patches before public release won't count for 2.13, although they will for
+  2.12 -- be careful to avoid confusion!  patchlevel.h will be the last thing
+  to change.
+
+Cray updates to deal with arithmetic problems.
+
+Minor test suite updates.
+
+Fixed latent bug in parser (freeing memory).
+
+Changes from 2.12.34 to 2.12.35
+-------------------------------
+
+VMS updates.
+
+Flush stdout at top of err() and stderr at bottom.
+
+Fixed bug in eval_condition() -- it wasn't testing for MAYBE_NUM and
+  doing the force_number().
+
+Included the missing manyfiles.awk and a new test to catch the above bug which
+  I am amazed wasn't already caught by the test suite -- it's pretty basic.
+
+Changes from 2.12.33 to 2.12.34
+-------------------------------
+
+Atari updates -- including bug fix.
+
+More VMS updates -- also nuke vms/version.com.
+
+Fixed bug in handling of large numbers of redirections -- it was probably never
+  tested before (blush!).
+
+Minor rearrangement of code in r_force_number().
+
+Made chem and regtest tests a bit more portable (Ultrix again).
+
+Added another test -- manyfiles -- not invoked under any other test -- very Unix
+  specific.
+
+Rough beginning of LIMITATIONS file -- need my AWK book to complete it.
+
+Changes from 2.12.32 to 2.12.33
+-------------------------------
+
+Expunge debug.? from various files.
+
+Remove vestiges of Floor and Ceil kludge.
+
+Special case integer division -- mainly for Cray, but maybe someone else
+  will benefit.
+
+Workaround for iop_close closing an output pipe descriptor on Cray --
+  not conditional since I think it may fix a bug on SGI as well and I don't
+  think it can hurt elsewhere.
+
+Fixed memory leak in assoc_lookup().
+
+Small cleanup in test suite.
+
+Changes from 2.12.31 to 2.12.32
+-------------------------------
+
+Nuked debug.c and debugging flag -- there are better ways.
+
+Nuked version.sh and version.c in subdirectories.
+
+Fixed bug in handling of IGNORECASE.
+
+Fixed bug when FIELDWIDTHS was set via -v option.
+
+Fixed (obscure) bug when $0 is assigned a numerical value.
+
+Fixed so that escape sequences in command-line assignments work (as it already
+  said in the comment).
+
+Added a few cases to test suite.
+
+Moved support/* back into distribution.
+
+VMS updates.
+
+Changes from 2.12.30 to 2.12.31
+-------------------------------
+
+Cosmetic manual page changes.
+
+Updated sunos3 config.
+
+Small changes in test suite including renaming files over 14 chars. in length.
+
+Changes from 2.12.29 to 2.12.30
+-------------------------------
+
+Bug fix for many string concatenations in a row.
+
+Changes from 2.12.28 to 2.12.29
+-------------------------------
+
+Minor cleanup in awk.y
+
+Minor VMS update.
+ 
+Minor atari update.
+
+Changes from 2.12.27 to 2.12.28
+-------------------------------
+
+Got rid of the debugging goop in eval.c -- there are better ways.
+
+Sequent port.
+
+VMS changes left out of the last patch -- sigh!  config/vms.h renamed
+  to config/vms-conf.h.
+
+Fixed missing/tzset.c
+
+Removed use of gcvt() and GCVT_MISSING -- turns out it was no faster than
+  sprintf("%g") and caused all sorts of portability headaches.
+
+Tuned get_field() -- it was unnecessarily parsing the whole record on reference
+  to $0.
+
+Tuned interpret() a bit in the rule_node loop.
+
+In r_force_number(), worked around bug in Uglix strtod() and got rid of 
+  ugly do{}while(0) at Michal's urging.
+
+Replaced do_deref() and deref with unref(node) -- much cleaner and a bit faster.
+
+Got rid of assign_number() -- contrary to comment, it was no faster than
+  just making a new node and freeing the old one.
+
+Replaced make_number() and tmp_number() with macros that call mk_number().
+
+Changed freenode() and newnode() into macros -- the latter is getnode()
+  which calls more_nodes() as necessary.
+
+Changes from 2.12.26 to 2.12.27
+-------------------------------
+
+Completion of Cray 2 port (includes a kludge for floor() and ceil()
+  that may go or be changed -- I think that it may just be working around
+  a bug in chem that is being tweaked on the Cray).
+
+More VMS updates.
+
+Moved kludge over yacc's insertion of malloc and realloc declarations
+  from protos.h to the Makefile.
+
+Added a lisp interpreter in awk to the test suite.  (Invoked under
+  bigtest.)
+
+Cleanup in r_force_number() -- I had never gotten around to a thorough
+  profile of the cache code and it turns out to be not worth it.
+
+Performance boost -- do lazy force_number()'ing for fields etc. i.e.
+  flag them (MAYBE_NUM) and call force_number only as necessary.
+
+Changes from 2.12.25 to 2.12.26
+-------------------------------
+
+Rework of regexp stuff so that dynamic regexps have reasonable
+  performance -- string used for compiled regexp is stored and
+  compared to new string -- if same, no recompilation is necessary.
+  Also, very dynamic regexps cause dfa-based searching to be turned
+  off.
+
+Code in dev_open() is back to returning fileno(std*) rather than
+  dup()ing it.  This will be documented.  Sorry for the run-around
+  on this.
+
+Minor atari updates.
+
+Minor vms update.
+
+Missing file from MSDOS port.
+
+Added warning (under lint) if third arg. of [g]sub is a constant and
+  handle it properly in the code (i.e. return how many matches).
+
+Changes from 2.12.24 to 2.12.25
+-------------------------------
+
+MSDOS port.
+
+Non-consequential changes to regexp variables in preparation for
+  a more serious change to fix a serious performance problem.
+
+Changes from 2.12.23 to 2.12.24
+-------------------------------
+
+Fixed bug in output flushing introduced a few patches back.  This caused
+  serious performance losses.
+
+Changes from 2.12.22 to 2.12.23
+-------------------------------
+
+Accidently left config/cray2-60 out of last patch.
+
+Added some missing dependencies to Makefile.
+
+Cleaned up mkconf a bit; made yacc the default parser (no alloca needed,
+  right?); added rs6000 hook for signed characters.
+
+Made regex.c with NO_ALLOCA undefined work.
+
+Fixed bug in dfa.c for systems where free(NULL) bombs.
+
+Deleted a few cant_happen()'s that *really* can't hapen.
+
+Changes from 2.12.21 to 2.12.22
+-------------------------------
+
+Added to config stuff the ability to choose YACC rather than bison.
+
+Fixed CHAR_UNSIGNED in config.h-dist.
+
+Second arg. of strtod() is char ** rather than const char **. 
+
+stackb is now initially malloc()'ed since it may be realloc()'ed.
+
+VMS updates.
+
+Added SIZE_T_MISSING to config stuff and a default typedef to awk.h.
+  (Maybe it is not needed on any current systems??)
+
+re_compile_pattern()'s size is now size_t unconditionally.
+
+Changes from 2.12.20 to 2.12.21
+-------------------------------
+
+Corrected missing/gcvt.c.
+
+Got rid of use of dup2() and thus DUP_MISSING.
+
+Updated config/sgi33.
+
+Turned on (and fixed) in cmp_nodes() the behaviour that I *hope* will be in
+  POSIX 1003.2 for relational comparisons.
+
+Small updates to test suite.
+
+Changes from 2.12.19 to 2.12.20
+-------------------------------
+
+Sloppy, sloppy, sloppy!!  I didn't even try to compile the last two
+  patches.  This one fixes goofs in regex.c.
+
+Changes from 2.12.18 to 2.12.19
+-------------------------------
+
+Cleanup of last patch.
+
+Changes from 2.12.17 to 2.12.18
+-------------------------------
+
+Makefile renamed to Makefile-dist.
+
+Added alloca() configuration to mkconf.  (A bit kludgey.)  Just
+  add a single line containing ALLOCA_PW, ALLOCA_S or ALLOCA_C
+  to the appropriate config file to have Makefile-dist edited
+  accordingly.
+
+Reorganized output flushing to correspond with new semantics of
+  devopen() on "/dev/std*" etc.
+
+Fixed rest of last goof!!
+
+Save and restore errno in do_pathopen().
+
+Miscellaneous atari updates.
+
+Get rid of the trailing comma in the NODETYPE definition (Cray
+  compiler won't take it).
+
+Try  to make the use of `const' consistent since Cray compiler is
+  fussy about that.  See the changes to `basename' and `myname'.
+
+It turns out that, according to section 3.8.3 (Macro Replacement)
+  of the ANSI Standard:  ``If there are sequences of preprocessing
+  tokens within the list of arguments that would otherwise act as
+  preprocessing directives, the behavior is undefined.''  That means
+  that you cannot count on the behavior of the declaration of
+  re_compile_pattern in awk.h, and indeed the Cray compiler chokes on it.
+
+Replaced alloca with malloc/realloc/free in regex.c.  It was much simpler
+  than expected.  (Inside NO_ALLOCA for now -- by default no alloca.)
+
+Added a configuration file, config/cray60, for Unicos-6.0.
+
+Changes from 2.12.16 to 2.12.17
+-------------------------------
+
+Ooops.  Goofed signal use in last patch.
+
+Changes from 2.12.15 to 2.12.16
+-------------------------------
+
+RENAMED *_dir to just * (e.g. missing_dir).
+
+Numerous VMS changes.
+
+Proper inclusion of atari and vms files.
+
+Added experimental (ifdef'd out) RELAXED_CONTINUATION and DEFAULT_FILETYPE
+ -- please comment on these!
+
+Moved pathopen() to io.c (sigh).
+
+Put local directory ahead in default AWKPATH.
+
+Added facility in mkconf to echo comments on stdout:  lines beginning
+  with "#echo " will have the remainder of the line echoed when mkconf is run.
+  Any lines starting with "#" will otherwise be treated as comments.  The
+  intent is to be able to say:
+  "#echo Make sure you uncomment alloca.c in the Makefile"
+  or the like.
+
+Prototype fix for V.4
+
+Fixed version_string to not print leading @(#).
+
+Fixed FIELDWIDTHS to work with strict (turned out to be easy).
+
+Fixed conf for V.2.
+
+Changed semantics of /dev/fd/n to be like on real /dev/fd.
+
+Several configuration and updates in the makefile.
+
+Updated manpage.
+
+Include tzset.c and system.c from missing_dir that were accidently left out of
+  the last patch.
+
+Fixed bug in cmdline variable assignment -- arg was getting freed(!) in
+  call to variable.
+
+Backed out of parse-time constant folding for now, until I can figure out
+  how to do it right.
+
+Fixed devopen() so that getline <"-" works.
+
+Changes from 2.12.14 to 2.12.15
+-------------------------------
+
+Changed config/* to a condensed form that can be used with mkconf to generate
+  a config.h from config.h-dist -- much easier to maintain.  Please chaeck
+  carefully against what you had before for a particular system and report
+  any problems.  vms.h remains separate since the stuff at the bottom
+  didn't quite fit the mkconf model -- hopefully cleared up later.
+
+Fixed bug in grammar -- didn't allow function definition to be separated from 
+  other rules by a semi-colon.
+
+VMS fix to #includes in missing.c -- should we just be including awk.h?
+
+Updated README for texinfo.tex version.
+
+Updating of copyright in all .[chy] files.
+
+Added but commented out Michal's fix to strftime.
+
+Added tzset() emulation based on Rick Adams' code.  Added TZSET_MISSING to
+	config.h-dist.
+
+Added strftime.3 man page for missing_dir
+
+More posix:	func, **, **= don't work in -W posix
+
+More lint:	^, ^= not in old awk
+
+gawk.1:		removed ref to -DNO_DEV_FD, other minor updating.
+
+Style change:  pushbak becomes pushback() in yylex().
+
+Changes from 2.12.13 to 2.12.14
+-------------------------------
+
+Better (?) organization of awk.h -- attempt to keep all system dependencies
+  near the top and move some of the non-general things out of the config.h
+  files.
+
+Change to handling of SYSTEM_MISSING.
+
+Small change to ultrix config.
+
+Do "/dev/fd/*" etc. checking at runtime.
+
+First pass at VMS port.
+
+Improvements to error handling (when lexeme spans buffers).
+
+Fixed backslash handling -- why didn't I notice this sooner?
+
+Added programs from book to test suite and new target "bigtest" to Makefile.
+
+Changes from 2.12.12 to 2.12.13
+-------------------------------
+
+Recognize OFS and ORS specially so that OFS = 9 works without efficiency hit.
+  Took advantage of opportunity to tune do_print*() for about 10% win on a
+  print with 5 args (i.e. small but significant).
+
+Somewhat pervasive changes to reconcile CONVFMT vs. OFMT.
+
+Better initialization of builtin vars.
+
+Make config/* consistent wrt STRTOL_MISSING.
+
+Small portability improvement to alloca.s
+
+Improvements to lint code in awk.y
+
+Replaced strtol() with a better one by Chris Torek.
+
+Changes from 2.12.11 to 2.12.12
+-------------------------------
+
+Added PORTS file to record successful ports.
+
+Added #define const to nothing if not STDC and added const to strtod() header.
+
+Added * to printf capabilities and partially implemented ' ' and '+' (has an
+  effect for %d only, silently ignored for other formats).  I'm afraid that's
+  as far as I want to go before I look at a complete replacement for
+  do_sprintf().
+
+Added warning for /regexp/ on LHS of MATCHOP.
+
+Changes from 2.12.10 to 2.12.11
+-------------------------------
+
+Small Makefile improvements.
+
+Some remaining nits from the NeXT port.
+
+Got rid of bcopy() define in awk.h -- not needed anymore (??)
+
+Changed private in builtin.c -- it is special on Sequent.
+
+Added subset implementation of strtol() and STRTOL_MISSING.
+
+A little bit of cleanup in debug.c, dfa.c.
+
+Changes from 2.12.9 to 2.12.10
+------------------------------
+
+Redid compatability checking and checking for # of args.
+
+Removed all references to variables[] from outside awk.y, in preparation
+  for a more abstract interface to the symbol table.
+
+Got rid of a remaining use of bcopy() in regex.c.
+
+Changes from 2.12.8 to 2.12.9
+-----------------------------
+
+Portability improvements for atari, next and decstation.
+
+Bug fix in substr() -- wasn't handling 3rd arg. of -1 properly.
+
+Manpage updates.
+
+Moved support from src release to doc release.
+
+Updated FUTURES file.
+
+Added some "lint" warnings.
+
+Changes from 2.12.7 to 2.12.8
+-----------------------------
+
+Changed time() to systime().
+
+Changed warning() in snode() to fatal().
+
+strftime() now defaults second arg. to current time.
+
+Changes from 2.12.6 to 2.12.7
+-----------------------------
+
+Fixed bug in sub_common() involving inadequate allocation of a buffer.
+
+Added some missing files to the Makefile.
+
+Changes from 2.12.5 to 2.12.6
+-----------------------------
+
+Fixed bug wherein non-redirected getline could call iop_close() just
+  prior to a call from do_input().
+
+Fixed bug in handling of /dev/stdout and /dev/stderr.
+
+Changes from 2.12.4 to 2.12.5
+-----------------------------
+
+Updated README and support directory.
+
+Changes from 2.12.3 to 2.12.4
+-----------------------------
+
+Updated CHANGES and TODO (should have been done in previous 2 patches).
+
+Changes from 2.12.2 to 2.12.3
+-----------------------------
+
+Brought regex.c and alloca.s into line with current FSF versions.
+
+Changes from 2.12.1 to 2.12.2
+-----------------------------
+
+Portability improvements; mostly moving system prototypes out of awk.h
+
+Introduction of strftime.
+
+Use of CONVFMT.
+
+Changes from 2.12 to 2.12.1
+-----------------------------
+
+Consolidated treatment of command-line assignments (thus correcting the
+-v treatment).
+
+Rationalized builtin-variable handling into a table-driven process, thus
+simplifying variable() and eliminating spc_var().
+
+Fixed bug in handling of command-line source that ended in a newline.
+
+Simplified install() and lookup().
+
+Did away with double-mallocing of identifiers and now free second and later
+instances of a name, after the first gets installed into the symbol table.
+
+Treat IGNORECASE specially, simplifying a lot of code, and allowing
+checking against strict conformance only on setting it, rather than on each
+pattern match.
+
+Fixed regexp matching when IGNORECASE is non-zero (broken when dfa.c was 
+added).
+
+Fixed bug where $0 was not being marked as valid, even after it was rebuilt.
+This caused mangling of $0.
+
+
+Changes from 2.11.1 to 2.12
+-----------------------------
+
+Makefile:
+
+Portability improvements in Makefile.
+Move configuration stuff into config.h
+
+FSF files:
+
+Synchronized alloca.[cs] and regex.[ch] with FSF.
+
+array.c:
+
+Rationalized hash routines into one with a different algorithm.
+delete() now works if the array is a local variable.
+Changed interface of assoc_next() and avoided dereferencing past the end of the
+  array.
+
+awk.h:
+
+Merged non-prototype and prototype declarations in awk.h.
+Expanded tree_eval #define to short-circuit more calls of r_tree_eval().
+
+awk.y:
+
+Delinted some of the code in the grammar.
+Fixed and improved some of the error message printing.
+Changed to accomodate unlimited length source lines.
+Line continuation now works as advertised.
+Source lines can be arbitrarily long.
+Refined grammar hacks so that /= assignment works.  Regular expressions
+  starting with /= are recognized at the beginning of a line, after && or ||
+  and after ~ or !~.  More contexts can be added if necessary.
+Fixed IGNORECASE (multiple scans for backslash).
+Condensed expression_lists in array references.
+Detect and warn for correct # args in builtin functions -- call most of them
+  with a fixed number (i.e. fill in defaults at parse-time rather than at
+  run-time).
+Load ENVIRON only if it is referenced (detected at parse-time).
+Treat NF, FS, RS, NR, FNR specially at parse time, to improve run time.
+Fold constant expressions at parse time.
+Do make_regexp() on third arg. of split() at parse tiem if it is a constant.
+
+builtin.c:
+
+srand() returns 0 the first time called.
+Replaced alloca() with malloc() in do_sprintf().
+Fixed setting of RSTART and RLENGTH in do_match().
+Got rid of get_{one,two,three} and allowance for variable # of args. at
+  run-time -- this is now done at parse-time.
+Fixed latent bug in [g]sub whereby changes to $0 would never get made.
+Rewrote much of sub_common() for simplicity and performance.
+Added ctime() and time() builtin functions (unless -DSTRICT).  ctime() returns
+  a time string like the C function, given the number of seconds since the epoch
+  and time() returns the current time in seconds.
+do_sprintf() now checks for mismatch between format string and number of
+  arguments supplied.
+
+dfa.c
+
+This is borrowed (almost unmodified) from GNU grep to provide faster searches.
+
+eval.c
+
+Node_var, Node_var_array and Node_param_list handled from macro rather
+  than in r_tree_eval().
+Changed cmp_nodes() to not do a force_number() -- this, combined with a 
+    force_number() on ARGV[] and ENVIRON[] brings it into line with other awks
+Greatly simplified cmp_nodes().
+Separated out Node_NF, Node_FS, Node_RS, Node_NR and Node_FNR in get_lhs().
+All adjacent string concatenations now done at once.
+
+field.c
+
+Added support for FIELDWIDTHS.
+Fixed bug in get_field() whereby changes to a field were not always
+  properly reflected in $0.
+Reordered tests in parse_field() so that reference off the end of the buffer
+  doesn't happen.
+set_FS() now sets *parse_field i.e. routine to call depending on type of FS.
+It also does make_regexp() for FS if needed.  get_field() passes FS_regexp
+  to re_parse_field(), as does do_split().
+Changes to set_field() and set_record() to avoid malloc'ing and free'ing the
+  field nodes repeatedly.  The fields now just point into $0 unless they are
+  assigned to another variable or changed.  force_number() on the field is
+  *only* done when the field is needed.
+
+gawk.1
+
+Fixed troff formatting problem on .TP lines.
+
+io.c
+
+Moved some code out into iop.c.
+Output from pipes and system() calls is properly synchronized.
+Status from pipe close properly returned.
+Bug in getline with no redirect fixed.
+
+iop.c
+
+This file contains a totally revamped get_a_record and associated code.
+
+main.c
+
+Command line programs no longer use a temporary file.
+Therefore, tmpnam() no longer required.
+Deprecated -a and -e options -- they will go away in the next release,
+  but for now they cause a warning.
+Moved -C, -V, -c options to -W ala posix.
+Added -W posix option: throw out \x
+Added -W lint option.
+
+
+node.c
+
+force_number() now allows pure numerics to have leading whitespace.
+Added make_string facility to optimize case of adding an already malloc'd
+  string.
+Cleaned up and simplified do_deref().
+Fixed bug in handling of stref==255 in do_deref().
+
+re.c
+
+contains the interface to regexp code
+
+Changes from 2.11.1 to FSF version of same
+------------------------------------------
+Thu Jan  4 14:19:30 1990  Jim Kingdon  (kingdon at albert)
+
+	* Makefile (YACC): Add -y to bison part.
+
+	* missing.c: Add #include <stdio.h>.
+
+Sun Dec 24 16:16:05 1989  David J. MacKenzie  (djm at hobbes.ai.mit.edu)
+
+	* * Makefile: Add (commented out) default defines for Sony News.
+
+	* awk.h: Move declaration of vprintf so it will compile when
+	-DVPRINTF_MISSING is defined.
+
+Mon Nov 13 18:54:08 1989  Robert J. Chassell  (bob at apple-gunkies.ai.mit.edu)
+
+        * gawk.texinfo: changed @-commands that are not part of the
+          standard, currently released texinfmt.el to those that are.
+          Otherwise, only people with the as-yet unreleased makeinfo.c can
+          format this file.
+
+Changes from 2.11beta to 2.11.1 (production)
+--------------------------------------------
+
+Went from "beta" to production status!!!
+
+Now flushes stdout before closing pipes or redirected files to
+synchonize output.
+
+MS-DOS changes added in.
+
+Signal handler return type parameterized in Makefile and awk.h and
+some lint removed.  debug.c cleaned up.
+
+Fixed FS splitting to never match null strings, per book.
+
+Correction to the manual's description of FS.
+
+Some compilers break on char *foo = "string" + 4 so fixed version.sh and
+main.c.
+
+Changes from 2.10beta to 2.11beta
+---------------------------------
+
+This release fixes all reported bugs that we could reproduce.  Probably
+some of the changes are not documented here.
+
+The next release will probably not be a beta release!
+
+The most important change is the addition of the -nostalgia option. :-)
+
+The documentation has been improved and brought up-to-date.
+
+There has been a lot of general cleaning up of the code that is not otherwise
+documented here.  There has been a movement toward using standard-conforming
+library routines and providing them (in missing.d) for systems lacking them.
+Improved (hopefully) configuration through Makfile modifications and missing.c.
+In particular, straightened out confusion over vprintf #defines, declarations
+etc.
+
+Deleted RCS log comments from source, to reduce source size by about one third.
+Most of them were horribly out-of-date, anyway.
+
+Renamed source files to reflect (for the most part) their contents.
+
+More and improved error messages.  Cleanup and fixes to yyerror().
+String constants are not altered in input buffer, so error messages come out 
+better.  Fixed usage message.  Make use of ANSI C strerror() function
+(provided).
+
+Plugged many more memory leaks.  The memory consumption is now quite
+reasonable over a wide range of programs.
+
+Uses volatile declaration if STDC > 0 to avoid problems due to longjmp.
+
+New -a and -e options to use awk or egrep style regexps, respectively,
+since POSIX says awk should use egrep regexps.  Default is -a.
+
+Added -v option for setting variables before the first file is encountered.
+Version information now uses -V and copyleft uses -C.
+
+Added a patchlevel.h file and its use for -V and -C.
+
+Append_right() optimized for major improvement to programs with a *lot*
+of statements.
+
+Operator precedence has been corrected to match draft Posix.
+
+Tightened up grammar for builtin functions so that only length
+may be called without arguments or parentheses.
+
+/regex/ is now a normal expression that can appear in any expression
+context.
+
+Allow /= to begin a regexp.  Allow ..[../..].. in a regexp.
+
+Allow empty compound statements ({}).
+
+Made return and next illegal outside a function and in BEGIN/END respectively.
+
+Division by zero is now illegal and causes a fatal error.
+
+Fixed exponentiation so that x ^ 0 and x ^= 0 both return 1.
+
+Fixed do_sqrt, do_log, and do_exp to do argument/return checking and
+print an error message, per the manual.
+
+Fixed main to catch SIGSEGV to get source and data file line numbers.
+
+Fixed yyerror to print the ^ at the beginning of the bad token, not the end.
+
+Fix to substr() builtin:  it was failing if the arguments
+weren't already strings.
+
+Added new node value flag NUMERIC to indicate that a variable is
+purely a number as opposed to type NUM which indicates that
+the node's numeric value is valid.  This is set in make_number(),
+tmp_number and r_force_number() when appropriate and used in
+cmp_nodes().  This fixed a bug in comparison of variables that had
+numeric prefixes.  The new code uses strtod() and eliminates is_a_number().
+A simple strtod() is provided for systems lacking one.  It does no
+overflow checking, so could be improved.
+
+Simplification and efficiency improvement in force_string.
+
+Added performance tweak in r_force_number().
+
+Fixed a bug with nested loops and break/continue in functions.
+
+Fixed inconsistency in handling of empty fields when $0 has to be rebuilt.
+Happens to simplify rebuild_record().
+
+Cleaned up the code associated with opening a pipe for reading.  Gawk
+now has its own popen routine (gawk_popen) that allocates an IOBUF
+and keeps track of the pid of the child process.  gawk_pclose
+marks the appropriate child as defunct in the right struct redirect.
+
+Cleaned up and fixed close_redir().
+
+Fixed an obscure bug to do with redirection.  Intermingled ">" and ">>"
+redirects did not output in a predictable order.
+
+Improved handling of output bufferring:  now all print[f]s redirected to a tty
+or pipe are flushed immediately and non-redirected output to a tty is flushed
+before the next input record is read.
+
+Fixed a bug in get_a_record() where bcopy() could have copied over
+a random pointer.
+
+Fixed a bug when RS="" and records separated by multiple blank lines.
+
+Got rid of SLOWIO code which was out-of-date anyway.
+
+Fix in get_field() for case where $0 is changed and then $(n) are
+changed and then $0 is used.
+
+Fixed infinite loop on failure to open file for reading from getline.
+Now handles redirect file open failures properly.
+
+Filenames such as /dev/stdin now allowed on the command line as well as
+in redirects.
+
+Fixed so that gawk '$1' where $1 is a zero tests false.
+
+Fixed parsing so that `RLENGTH -1' parses the same as `RLENGTH - 1',
+for example.
+
+The return from a user-defined function now defaults to the Null node.
+This fixes a core-dump-causing bug when the return value  of a function
+is used and that function returns no value.
+
+Now catches floating point exceptions to avoid core dumps.
+
+Bug fix for deleting elements of an array -- under some conditions, it was
+deleting more than one element at a time.
+
+Fix in AWKPATH code for running off the end of the string.
+
+Fixed handling of precision in *printf calls.  %0.2d now works properly,
+as does %c.  [s]printf now recognizes %i and %X.
+
+Fixed a bug in printing of very large (>240) strings.
+
+Cleaned up erroneous behaviour for RS == "".
+
+Added IGNORECASE support to index().
+
+Simplified and fixed newnode/freenode.
+
+Fixed reference to $(anything) in a BEGIN block.
+
+Eliminated use of USG rand48().
+
+Bug fix in force_string for machines with 16-bit ints.
+
+Replaced use of mktemp() with tmpnam() and provided a partial implementation of
+the latter for systems that don't have it.
+
+Added a portability check for includes in io.c.
+
+Minor portability fix in alloc.c plus addition of xmalloc().
+
+Portability fix:  on UMAX4.2, st_blksize is zero for a pipe, thus breaking
+iop_alloc() -- fixed.
+
+Workaround for compiler bug on Sun386i in do_sprintf.
+
+More and improved prototypes in awk.h.
+
+Consolidated C escape parsing code into one place.
+
+strict flag is now turned on only when invoked with compatability option.
+It now applies to fewer things.
+
+Changed cast of f._ptr in vprintf.c from (unsigned char *) to (char *).
+Hopefully this is right for the systems that use this code (I don't).
+
+Support for pipes under MSDOS added.
diff --git a/gnu/usr.bin/awk/PORTS b/gnu/usr.bin/awk/PORTS
new file mode 100644
index 000000000000..95e133f9dd03
--- /dev/null
+++ b/gnu/usr.bin/awk/PORTS
@@ -0,0 +1,32 @@
+A recent version of gawk has been successfully compiled and run "make test"
+on the following:
+
+Sun 4/490 running 4.1
+NeXT running 2.0
+DECstation 3100 running Ultrix 4.0 or Ultrix 3.1 (different config)
+AtariST (16-bit ints, gcc compiler, byacc, running under TOS)
+ESIX V.3.2 Rev D (== System V Release 3.2), the 386.  compiler was gcc + bison
+IBM RS/6000 (see README.rs6000)
+486 running SVR4, using cc and bison
+SGI running IRIX 3.3 using gcc (fails with cc)
+Sequent Balance running Dynix V3.1
+Cray Y-MP8 running Unicos 6.0.11
+Cray 2 running Unicos 6.1 (modulo trailing zeroes in chem)
+VAX/VMS V5.x (should also work on 4.6 and 4.7)
+VMS POSIX V1.0, V1.1
+OpenVMS AXP V1.0
+MSDOS - Microsoft C 5.1, compiles and runs very simple testing
+BSD 4.4alpha
+
+From:	ghazi@caip.rutgers.edu (Kaveh R. Ghazi):
+
+arch				configured as:
+----				--------------
+Hpux 9.0			hpux8x
+NeXTStep 2.0			next20
+Sgi Irix 4.0.5 (/bin/cc)	sgi405.cc  (new file)
+Stardent Titan 1500 OSv2.5	sysv3
+Stardent Vistra (i860) SVR4	sysv4
+SunOS 4.1.2			sunos41
+Tektronix XD88 (UTekV 3.2e)	sysv3
+Ultrix 4.2			ultrix41
diff --git a/gnu/usr.bin/awk/POSIX b/gnu/usr.bin/awk/POSIX
new file mode 100644
index 000000000000..f2405420aedf
--- /dev/null
+++ b/gnu/usr.bin/awk/POSIX
@@ -0,0 +1,95 @@
+Right now, the numeric vs. string comparisons are screwed up in draft
+11.2.  What prompted me to check it out was the note in gnu.bug.utils
+which observed that gawk was doing the comparison  $1 == "000"
+numerically.  I think that we can agree that intuitively, this should
+be done as a string comparison.  Version 2.13.2 of gawk follows the
+current POSIX draft.  Following is how I (now) think this
+stuff should be done. 
+
+1.  A numeric literal or the result of a numeric operation has the NUMERIC
+    attribute.
+
+2.  A string literal or the result of a string operation has the STRING
+    attribute.
+
+3.  Fields, getline input, FILENAME, ARGV elements, ENVIRON elements and the
+    elements of an array created by split() that are numeric strings
+    have the STRNUM attribute.  Otherwise, they have the STRING attribute.
+    Uninitialized variables also have the STRNUM attribute.
+
+4.  Attributes propagate across assignments, but are not changed by
+    any use.  (Although a use may cause the entity to acquire an additional
+    value such that it has both a numeric and string value -- this leaves the
+    attribute unchanged.)
+
+When two operands are compared, either string comparison or numeric comparison
+may be used, depending on the attributes of the operands, according to the
+following (symmetric) matrix:
+
+	+----------------------------------------------
+	|	STRING		NUMERIC		STRNUM
+--------+----------------------------------------------
+	|
+STRING	|	string		string		string
+	|
+NUMERIC	|	string		numeric		numeric
+	|
+STRNUM	|	string		numeric		numeric
+--------+----------------------------------------------
+
+So, the following program should print all OKs.
+
+echo '0e2 0a 0 0b
+0e2 0a 0 0b' |
+$AWK '
+NR == 1 {
+	num = 0
+	str = "0e2"
+
+	print ++test ": " (	(str == "0e2")	? "OK" : "OOPS" )
+	print ++test ": " (	("0e2" != 0)	? "OK" : "OOPS" )
+	print ++test ": " (	("0" != $2)	? "OK" : "OOPS" )
+	print ++test ": " (	("0e2" == $1)	? "OK" : "OOPS" )
+
+	print ++test ": " (	(0 == "0")	? "OK" : "OOPS" )
+	print ++test ": " (	(0 == num)	? "OK" : "OOPS" )
+	print ++test ": " (	(0 != $2)	? "OK" : "OOPS" )
+	print ++test ": " (	(0 == $1)	? "OK" : "OOPS" )
+
+	print ++test ": " (	($1 != "0")	? "OK" : "OOPS" )
+	print ++test ": " (	($1 == num)	? "OK" : "OOPS" )
+	print ++test ": " (	($2 != 0)	? "OK" : "OOPS" )
+	print ++test ": " (	($2 != $1)	? "OK" : "OOPS" )
+	print ++test ": " (	($3 == 0)	? "OK" : "OOPS" )
+	print ++test ": " (	($3 == $1)	? "OK" : "OOPS" )
+	print ++test ": " (	($2 != $4)	? "OK" : "OOPS"	) # 15
+}
+{
+	a = "+2"
+	b = 2
+	if (NR % 2)
+		c = a + b
+	print ++test ": " (	(a != b)	? "OK" : "OOPS" ) # 16 and 22
+
+	d = "2a"
+	b = 2
+	if (NR % 2)
+		c = d + b
+	print ++test ": " (	(d != b)	? "OK" : "OOPS" )
+
+	print ++test ": " (	(d + 0 == b)	? "OK" : "OOPS" )
+
+	e = "2"
+	print ++test ": " (	(e == b "")	? "OK" : "OOPS" )
+
+	a = "2.13"
+	print ++test ": " (	(a == 2.13)	? "OK" : "OOPS" )
+
+	a = "2.130000"
+	print ++test ": " (	(a != 2.13)	? "OK" : "OOPS" )
+
+	if (NR == 2) {
+		CONVFMT = "%.6f"
+		print ++test ": " (	(a == 2.13)	? "OK" : "OOPS" )
+	}
+}'
diff --git a/gnu/usr.bin/awk/PROBLEMS b/gnu/usr.bin/awk/PROBLEMS
new file mode 100644
index 000000000000..3b7c5148bd8e
--- /dev/null
+++ b/gnu/usr.bin/awk/PROBLEMS
@@ -0,0 +1,6 @@
+This is a list of known problems in gawk 2.15.
+Hopefully they will all be fixed in the next major release of gawk.
+
+Please keep in mind that the code is still undergoing significant evolution.
+
+1. Gawk's printf is probably still not POSIX compliant.
diff --git a/gnu/usr.bin/awk/README b/gnu/usr.bin/awk/README
new file mode 100644
index 000000000000..f4bd3df806c8
--- /dev/null
+++ b/gnu/usr.bin/awk/README
@@ -0,0 +1,116 @@
+README:
+
+This is GNU Awk 2.15. It should be upwardly compatible with the
+System V Release 4 awk.  It is almost completely compliant with draft 11.3
+of POSIX 1003.2.
+
+This release adds new features -- see NEWS for details.
+
+See the installation instructions, below.
+
+Known problems are given in the PROBLEMS file.  Work to be done is
+described briefly in the FUTURES file.  Verified ports are listed in
+the PORTS file.  Changes in this version are summarized in the CHANGES file.
+Please read the LIMITATIONS and ACKNOWLEDGMENT files.
+
+Read the file POSIX for a discussion of how the standard says comparisons
+should be done vs. how they really should be done and how gawk does them.
+  
+To format the documentation with TeX, you must use texinfo.tex 2.53
+or later.  Otherwise footnotes look unacceptable.
+
+If you wish to remake the Info files, you should use makeinfo. The 2.15 
+version of makeinfo works with no errors.
+
+The man page is up to date.
+
+INSTALLATION:
+
+Check whether there is a system-specific README file for your system.
+
+Makefile.in may need some tailoring.  The only changes necessary should
+be to change installation targets or to change compiler flags.
+The changes to make in Makefile.in are commented and should be obvious.
+
+All other changes should be made in a config file.  Samples for
+various systems are included in the config directory.  Starting with
+2.11, our intent has been to make the code conform to standards (ANSI,
+POSIX, SVID, in that order) whenever possible, and to not penalize
+standard conforming systems.  We have included substitute versions of
+routines not universally available.  Simply add the appropriate define
+for the missing feature(s) on your system.
+
+If you have neither bison nor yacc, use the awktab.c file here.  It was
+generated with bison, and should have no AT&T code in it.  (Note that
+modifying awk.y without bison or yacc will be difficult, at best.  You might
+want to get a copy of bison from the FSF too.)
+
+If no config file is included for your system,  start by copying one
+for a similar system.  One way of determining the defines needed is to
+try to load gawk with nothing defined and see what routines are
+unresolved by the loader.  This should give you a good idea of how to
+proceed.
+
+The next release will use the FSF autoconfig program, so we are no longer 
+soliciting new config files.
+
+If you have an MS-DOS system, use the stuff in the pc directory.
+For an Atari there is an atari directory and similarly one for VMS.
+
+Chapter 16 of The GAWK Manual discusses configuration in detail.
+
+After successful compilation, do 'make test' to run a small test
+suite.  There should be no output from the 'cmp' invocations except in
+the cases where there are small differences in floating point values.
+If there are other differences, please investigate and report the
+problem.
+
+PRINTING THE MANUAL
+
+The 'support' directory contains texinfo.tex 2.65, which will be necessary
+for printing the manual, and the texindex.c program from the texinfo
+distribution which is also necessary.  See the makefile for the steps needed
+to get a DVI file from the manual.
+
+CAVEATS
+
+The existence of a patchlevel.h file does *N*O*T* imply a commitment on
+our part to issue bug fixes or patches.  It is there in case we should
+decide to do so.
+
+BUG REPORTS AND FIXES (Un*x systems):
+
+Please coordinate changes through David Trueman and/or Arnold Robbins.
+
+David Trueman
+Department of Mathematics, Statistics and Computing Science,
+Dalhousie University, Halifax, Nova Scotia, Canada
+
+UUCP:		{uunet utai watmath}!dalcs!david
+INTERNET:	david@cs.dal.ca
+
+Arnold Robbins
+1736 Reindeer Drive
+Atlanta, GA, 30329, USA
+
+INTERNET:	arnold@skeeve.atl.ga.us
+UUCP:		{ gatech, emory, emoryu1 }!skeeve!arnold
+
+BUG REPORTS AND FIXES (non-Unix ports):
+
+MS-DOS:
+	Scott Deifik
+	AMGEN Inc.
+	Amgen Center, Bldg.17-Dept.393
+	Thousand Oaks, CA  91320-1789
+	Tel-805-499-5725  ext.4677
+	Fax-805-498-0358
+	scottd@amgen.com
+
+VMS:
+	Pat Rankin
+	rankin@eql.caltech.edu (e-mail only)
+
+Atari ST:
+	Michal Jaegermann
+	NTOMCZAK@vm.ucs.UAlberta.CA  (e-mail only)
diff --git a/gnu/usr.bin/awk/array.c b/gnu/usr.bin/awk/array.c
new file mode 100644
index 000000000000..59be340c04df
--- /dev/null
+++ b/gnu/usr.bin/awk/array.c
@@ -0,0 +1,293 @@
+/*
+ * array.c - routines for associative arrays.
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "awk.h"
+
+static NODE *assoc_find P((NODE *symbol, NODE *subs, int hash1));
+
+NODE *
+concat_exp(tree)
+register NODE *tree;
+{
+	register NODE *r;
+	char *str;
+	char *s;
+	unsigned len;
+	int offset;
+	int subseplen;
+	char *subsep;
+
+	if (tree->type != Node_expression_list)
+		return force_string(tree_eval(tree));
+	r = force_string(tree_eval(tree->lnode));
+	if (tree->rnode == NULL)
+		return r;
+	subseplen = SUBSEP_node->lnode->stlen;
+	subsep = SUBSEP_node->lnode->stptr;
+	len = r->stlen + subseplen + 2;
+	emalloc(str, char *, len, "concat_exp");
+	memcpy(str, r->stptr, r->stlen+1);
+	s = str + r->stlen;
+	free_temp(r);
+	tree = tree->rnode;
+	while (tree) {
+		if (subseplen == 1)
+			*s++ = *subsep;
+		else {
+			memcpy(s, subsep, subseplen+1);
+			s += subseplen;
+		}
+		r = force_string(tree_eval(tree->lnode));
+		len += r->stlen + subseplen;
+		offset = s - str;
+		erealloc(str, char *, len, "concat_exp");
+		s = str + offset;
+		memcpy(s, r->stptr, r->stlen+1);
+		s += r->stlen;
+		free_temp(r);
+		tree = tree->rnode;
+	}
+	r = make_str_node(str, s - str, ALREADY_MALLOCED);
+	r->flags |= TEMP;
+	return r;
+}
+
+/* Flush all the values in symbol[] before doing a split() */
+void
+assoc_clear(symbol)
+NODE *symbol;
+{
+	int i;
+	NODE *bucket, *next;
+
+	if (symbol->var_array == 0)
+		return;
+	for (i = 0; i < HASHSIZE; i++) {
+		for (bucket = symbol->var_array[i]; bucket; bucket = next) {
+			next = bucket->ahnext;
+			unref(bucket->ahname);
+			unref(bucket->ahvalue);
+			freenode(bucket);
+		}
+		symbol->var_array[i] = 0;
+	}
+}
+
+/*
+ * calculate the hash function of the string in subs
+ */
+unsigned int
+hash(s, len)
+register char *s;
+register int len;
+{
+	register unsigned long h = 0, g;
+
+	while (len--) {
+		h = (h << 4) + *s++;
+		g = (h & 0xf0000000);
+		if (g) {
+			h = h ^ (g >> 24);
+			h = h ^ g;
+		}
+	}
+	if (h < HASHSIZE)
+		return h;
+	else
+		return h%HASHSIZE;
+}
+
+/*
+ * locate symbol[subs]
+ */
+static NODE *				/* NULL if not found */
+assoc_find(symbol, subs, hash1)
+NODE *symbol;
+register NODE *subs;
+int hash1;
+{
+	register NODE *bucket, *prev = 0;
+
+	for (bucket = symbol->var_array[hash1]; bucket; bucket = bucket->ahnext) {
+		if (cmp_nodes(bucket->ahname, subs) == 0) {
+			if (prev) {	/* move found to front of chain */
+				prev->ahnext = bucket->ahnext;
+				bucket->ahnext = symbol->var_array[hash1];
+				symbol->var_array[hash1] = bucket;
+			}
+			return bucket;
+		} else
+			prev = bucket;	/* save previous list entry */
+	}
+	return NULL;
+}
+
+/*
+ * test whether the array element symbol[subs] exists or not 
+ */
+int
+in_array(symbol, subs)
+NODE *symbol, *subs;
+{
+	register int hash1;
+
+	if (symbol->type == Node_param_list)
+		symbol = stack_ptr[symbol->param_cnt];
+	if (symbol->var_array == 0)
+		return 0;
+	subs = concat_exp(subs);	/* concat_exp returns a string node */
+	hash1 = hash(subs->stptr, subs->stlen);
+	if (assoc_find(symbol, subs, hash1) == NULL) {
+		free_temp(subs);
+		return 0;
+	} else {
+		free_temp(subs);
+		return 1;
+	}
+}
+
+/*
+ * SYMBOL is the address of the node (or other pointer) being dereferenced.
+ * SUBS is a number or string used as the subscript. 
+ *
+ * Find SYMBOL[SUBS] in the assoc array.  Install it with value "" if it
+ * isn't there. Returns a pointer ala get_lhs to where its value is stored 
+ */
+NODE **
+assoc_lookup(symbol, subs)
+NODE *symbol, *subs;
+{
+	register int hash1;
+	register NODE *bucket;
+
+	(void) force_string(subs);
+	hash1 = hash(subs->stptr, subs->stlen);
+
+	if (symbol->var_array == 0) {	/* this table really should grow
+					 * dynamically */
+		unsigned size;
+
+		size = sizeof(NODE *) * HASHSIZE;
+		emalloc(symbol->var_array, NODE **, size, "assoc_lookup");
+		memset((char *)symbol->var_array, 0, size);
+		symbol->type = Node_var_array;
+	} else {
+		bucket = assoc_find(symbol, subs, hash1);
+		if (bucket != NULL) {
+			free_temp(subs);
+			return &(bucket->ahvalue);
+		}
+	}
+
+	/* It's not there, install it. */
+	if (do_lint && subs->stlen == 0)
+		warning("subscript of array `%s' is null string",
+			symbol->vname);
+	getnode(bucket);
+	bucket->type = Node_ahash;
+	if (subs->flags & TEMP)
+		bucket->ahname = dupnode(subs);
+	else {
+		unsigned int saveflags = subs->flags;
+
+		subs->flags &= ~MALLOC;
+		bucket->ahname = dupnode(subs);
+		subs->flags = saveflags;
+	}
+	free_temp(subs);
+
+	/* array subscripts are strings */
+	bucket->ahname->flags &= ~NUMBER;
+	bucket->ahname->flags |= STRING;
+	bucket->ahvalue = Nnull_string;
+	bucket->ahnext = symbol->var_array[hash1];
+	symbol->var_array[hash1] = bucket;
+	return &(bucket->ahvalue);
+}
+
+void
+do_delete(symbol, tree)
+NODE *symbol, *tree;
+{
+	register int hash1;
+	register NODE *bucket, *last;
+	NODE *subs;
+
+	if (symbol->type == Node_param_list)
+		symbol = stack_ptr[symbol->param_cnt];
+	if (symbol->var_array == 0)
+		return;
+	subs = concat_exp(tree);	/* concat_exp returns string node */
+	hash1 = hash(subs->stptr, subs->stlen);
+
+	last = NULL;
+	for (bucket = symbol->var_array[hash1]; bucket; last = bucket, bucket = bucket->ahnext)
+		if (cmp_nodes(bucket->ahname, subs) == 0)
+			break;
+	free_temp(subs);
+	if (bucket == NULL)
+		return;
+	if (last)
+		last->ahnext = bucket->ahnext;
+	else
+		symbol->var_array[hash1] = bucket->ahnext;
+	unref(bucket->ahname);
+	unref(bucket->ahvalue);
+	freenode(bucket);
+}
+
+void
+assoc_scan(symbol, lookat)
+NODE *symbol;
+struct search *lookat;
+{
+	if (!symbol->var_array) {
+		lookat->retval = NULL;
+		return;
+	}
+	lookat->arr_ptr = symbol->var_array;
+	lookat->arr_end = lookat->arr_ptr + HASHSIZE;	/* added */
+	lookat->bucket = symbol->var_array[0];
+	assoc_next(lookat);
+}
+
+void
+assoc_next(lookat)
+struct search *lookat;
+{
+	while (lookat->arr_ptr < lookat->arr_end) {
+		if (lookat->bucket != 0) {
+			lookat->retval = lookat->bucket->ahname;
+			lookat->bucket = lookat->bucket->ahnext;
+			return;
+		}
+		lookat->arr_ptr++;
+		if (lookat->arr_ptr < lookat->arr_end)
+			lookat->bucket = *(lookat->arr_ptr);
+		else
+			lookat->retval = NULL;
+	}
+	return;
+}
diff --git a/gnu/usr.bin/awk/awk.1 b/gnu/usr.bin/awk/awk.1
new file mode 100644
index 000000000000..0338485e8db8
--- /dev/null
+++ b/gnu/usr.bin/awk/awk.1
@@ -0,0 +1,1873 @@
+.ds PX \s-1POSIX\s+1
+.ds UX \s-1UNIX\s+1
+.ds AN \s-1ANSI\s+1
+.TH GAWK 1 "Apr 15 1993" "Free Software Foundation" "Utility Commands"
+.SH NAME
+gawk \- pattern scanning and processing language
+.SH SYNOPSIS
+.B gawk
+[ POSIX or GNU style options ]
+.B \-f
+.I program-file
+[
+.B \-\^\-
+] file .\^.\^.
+.br
+.B gawk
+[ POSIX or GNU style options ]
+[
+.B \-\^\-
+]
+.I program-text
+file .\^.\^.
+.SH DESCRIPTION
+.I Gawk
+is the GNU Project's implementation of the AWK programming language.
+It conforms to the definition of the language in
+the \*(PX 1003.2 Command Language And Utilities Standard.
+This version in turn is based on the description in
+.IR "The AWK Programming Language" ,
+by Aho, Kernighan, and Weinberger,
+with the additional features defined in the System V Release 4 version
+of \*(UX
+.IR awk .
+.I Gawk
+also provides some GNU-specific extensions.
+.PP
+The command line consists of options to
+.I gawk
+itself, the AWK program text (if not supplied via the
+.B \-f
+or
+.B \-\^\-file
+options), and values to be made
+available in the
+.B ARGC
+and
+.B ARGV
+pre-defined AWK variables.
+.SH OPTIONS
+.PP
+.I Gawk
+options may be either the traditional \*(PX one letter options,
+or the GNU style long options.  \*(PX style options start with a single ``\-'',
+while GNU long options start with ``\-\^\-''.
+GNU style long options are provided for both GNU-specific features and
+for \*(PX mandated features.  Other implementations of the AWK language
+are likely to only accept the traditional one letter options.
+.PP
+Following the \*(PX standard,
+.IR gawk -specific
+options are supplied via arguments to the
+.B \-W
+option.  Multiple
+.B \-W
+options may be supplied, or multiple arguments may be supplied together
+if they are separated by commas, or enclosed in quotes and separated
+by white space.
+Case is ignored in arguments to the
+.B \-W
+option.
+Each
+.B \-W
+option has a corresponding GNU style long option, as detailed below.
+.PP
+.I Gawk
+accepts the following options.
+.TP
+.PD 0
+.BI \-F " fs"
+.TP
+.PD
+.BI \-\^\-field-separator= fs
+Use
+.I fs
+for the input field separator (the value of the
+.B FS
+predefined
+variable).
+.TP
+.PD 0
+\fB\-v\fI var\fB\^=\^\fIval\fR
+.TP
+.PD
+\fB\-\^\-assign=\fIvar\fB\^=\^\fIval\fR
+Assign the value
+.IR val ,
+to the variable
+.IR var ,
+before execution of the program begins.
+Such variable values are available to the
+.B BEGIN
+block of an AWK program.
+.TP
+.PD 0
+.BI \-f " program-file"
+.TP
+.PD
+.BI \-\^\-file= program-file
+Read the AWK program source from the file
+.IR program-file ,
+instead of from the first command line argument.
+Multiple
+.B \-f
+(or
+.BR \-\^\-file )
+options may be used.
+.TP \w'\fB\-\^\-copyright\fR'u+1n
+.PD 0
+.B "\-W compat"
+.TP
+.PD
+.B \-\^\-compat
+Run in
+.I compatibility
+mode.  In compatibility mode,
+.I gawk
+behaves identically to \*(UX
+.IR awk ;
+none of the GNU-specific extensions are recognized.
+See
+.BR "GNU EXTENSIONS" ,
+below, for more information.
+.TP
+.PD 0
+.B "\-W copyleft"
+.TP
+.PD 0
+.B "\-W copyright"
+.TP
+.PD 0
+.B \-\^\-copyleft
+.TP
+.PD
+.B \-\^\-copyright
+Print the short version of the GNU copyright information message on
+the error output.
+.TP
+.PD 0
+.B "\-W help"
+.TP
+.PD 0
+.B "\-W usage"
+.TP
+.PD 0
+.B \-\^\-help
+.TP
+.PD
+.B \-\^\-usage
+Print a relatively short summary of the available options on
+the error output.
+.TP
+.PD 0
+.B "\-W lint"
+.TP
+.PD 0
+.B \-\^\-lint
+Provide warnings about constructs that are
+dubious or non-portable to other AWK implementations.
+.ig
+.\" This option is left undocumented, on purpose.
+.TP
+.PD 0
+.B "\-W nostalgia"
+.TP
+.PD
+.B \-\^\-nostalgia
+Provide a moment of nostalgia for long time
+.I awk
+users.
+..
+.TP
+.PD 0
+.B "\-W posix"
+.TP
+.PD
+.B \-\^\-posix
+This turns on
+.I compatibility 
+mode, with the following additional restrictions:
+.RS
+.TP \w'\(bu'u+1n
+\(bu
+.B \ex
+escape sequences are not recognized.
+.TP
+\(bu
+The synonym
+.B func
+for the keyword
+.B function
+is not recognized.
+.TP
+\(bu
+The operators
+.B **
+and
+.B **=
+cannot be used in place of
+.B ^
+and
+.BR ^= .
+.RE
+.TP
+.PD 0
+.BI "\-W source=" program-text
+.TP
+.PD
+.BI \-\^\-source= program-text
+Use
+.I program-text
+as AWK program source code.
+This option allows the easy intermixing of library functions (used via the 
+.B \-f
+and
+.B \-\^\-file
+options) with source code entered on the command line.
+It is intended primarily for medium to large size AWK programs used
+in shell scripts.
+.sp .5
+The
+.B "\-W source="
+form of this option uses the rest of the command line argument for
+.IR program-text ;
+no other options to
+.B \-W
+will be recognized in the same argument.
+.TP
+.PD 0
+.B "\-W version"
+.TP
+.PD
+.B \-\^\-version
+Print version information for this particular copy of
+.I gawk
+on the error output.
+This is useful mainly for knowing if the current copy of
+.I gawk
+on your system
+is up to date with respect to whatever the Free Software Foundation
+is distributing.
+.TP
+.B \-\^\-
+Signal the end of options. This is useful to allow further arguments to the
+AWK program itself to start with a ``\-''.
+This is mainly for consistency with the argument parsing convention used
+by most other \*(PX programs.
+.PP
+Any other options are flagged as illegal, but are otherwise ignored.
+.SH AWK PROGRAM EXECUTION
+.PP
+An AWK program consists of a sequence of pattern-action statements
+and optional function definitions.
+.RS
+.PP
+\fIpattern\fB	{ \fIaction statements\fB }\fR
+.br
+\fBfunction \fIname\fB(\fIparameter list\fB) { \fIstatements\fB }\fR
+.RE
+.PP
+.I Gawk
+first reads the program source from the
+.IR program-file (s)
+if specified, or from the first non-option argument on the command line.
+The
+.B \-f
+option may be used multiple times on the command line.
+.I Gawk
+will read the program text as if all the
+.IR program-file s
+had been concatenated together.  This is useful for building libraries
+of AWK functions, without having to include them in each new AWK
+program that uses them.  To use a library function in a file from a
+program typed in on the command line, specify
+.B /dev/tty
+as one of the
+.IR program-file s,
+type your program, and end it with a
+.B ^D
+(control-d).
+.PP
+The environment variable
+.B AWKPATH
+specifies a search path to use when finding source files named with
+the 
+.B \-f
+option.  If this variable does not exist, the default path is
+\fB".:/usr/lib/awk:/usr/local/lib/awk"\fR.
+If a file name given to the
+.B \-f
+option contains a ``/'' character, no path search is performed.
+.PP
+.I Gawk
+executes AWK programs in the following order.
+First,
+.I gawk
+compiles the program into an internal form.
+Next, all variable assignments specified via the
+.B \-v
+option are performed.  Then,
+.I gawk
+executes the code in the
+.B BEGIN
+block(s) (if any),
+and then proceeds to read
+each file named in the
+.B ARGV
+array.
+If there are no files named on the command line,
+.I gawk
+reads the standard input.
+.PP
+If a filename on the command line has the form
+.IB var = val
+it is treated as a variable assignment. The variable
+.I var
+will be assigned the value
+.IR val .
+(This happens after any
+.B BEGIN
+block(s) have been run.)
+Command line variable assignment
+is most useful for dynamically assigning values to the variables
+AWK uses to control how input is broken into fields and records. It
+is also useful for controlling state if multiple passes are needed over
+a single data file.
+.PP
+If the value of a particular element of
+.B ARGV
+is empty (\fB""\fR),
+.I gawk
+skips over it.
+.PP
+For each line in the input,
+.I gawk
+tests to see if it matches any
+.I pattern
+in the AWK program.
+For each pattern that the line matches, the associated
+.I action
+is executed.
+The patterns are tested in the order they occur in the program.
+.PP
+Finally, after all the input is exhausted,
+.I gawk
+executes the code in the
+.B END
+block(s) (if any).
+.SH VARIABLES AND FIELDS
+AWK variables are dynamic; they come into existence when they are
+first used. Their values are either floating-point numbers or strings,
+or both,
+depending upon how they are used. AWK also has one dimension
+arrays; multiply dimensioned arrays may be simulated.
+Several pre-defined variables are set as a program
+runs; these will be described as needed and summarized below.
+.SS Fields
+.PP
+As each input line is read,
+.I gawk
+splits the line into
+.IR fields ,
+using the value of the
+.B FS
+variable as the field separator.
+If
+.B FS
+is a single character, fields are separated by that character.
+Otherwise,
+.B FS
+is expected to be a full regular expression.
+In the special case that
+.B FS
+is a single blank, fields are separated
+by runs of blanks and/or tabs.
+Note that the value of
+.B IGNORECASE
+(see below) will also affect how fields are split when
+.B FS
+is a regular expression.
+.PP
+If the
+.B FIELDWIDTHS
+variable is set to a space separated list of numbers, each field is
+expected to have fixed width, and
+.I gawk
+will split up the record using the specified widths.  The value of
+.B FS
+is ignored.
+Assigning a new value to
+.B FS
+overrides the use of
+.BR FIELDWIDTHS ,
+and restores the default behavior.
+.PP
+Each field in the input line may be referenced by its position,
+.BR $1 ,
+.BR $2 ,
+and so on.
+.B $0
+is the whole line. The value of a field may be assigned to as well.
+Fields need not be referenced by constants:
+.RS
+.PP
+.ft B
+n = 5
+.br
+print $n
+.ft R
+.RE
+.PP
+prints the fifth field in the input line.
+The variable
+.B NF
+is set to the total number of fields in the input line.
+.PP
+References to non-existent fields (i.e. fields after
+.BR $NF )
+produce the null-string. However, assigning to a non-existent field
+(e.g., 
+.BR "$(NF+2) = 5" )
+will increase the value of
+.BR NF ,
+create any intervening fields with the null string as their value, and
+cause the value of
+.B $0
+to be recomputed, with the fields being separated by the value of
+.BR OFS .
+.SS Built-in Variables
+.PP
+AWK's built-in variables are:
+.PP
+.TP \w'\fBFIELDWIDTHS\fR'u+1n
+.B ARGC
+The number of command line arguments (does not include options to
+.IR gawk ,
+or the program source).
+.TP
+.B ARGIND
+The index in
+.B ARGV
+of the current file being processed.
+.TP
+.B ARGV
+Array of command line arguments. The array is indexed from
+0 to
+.B ARGC
+\- 1.
+Dynamically changing the contents of
+.B ARGV
+can control the files used for data.
+.TP
+.B CONVFMT
+The conversion format for numbers, \fB"%.6g"\fR, by default.
+.TP
+.B ENVIRON
+An array containing the values of the current environment.
+The array is indexed by the environment variables, each element being
+the value of that variable (e.g., \fBENVIRON["HOME"]\fP might be
+.BR /u/arnold ).
+Changing this array does not affect the environment seen by programs which
+.I gawk
+spawns via redirection or the
+.B system()
+function.
+(This may change in a future version of
+.IR gawk .)
+.\" but don't hold your breath...
+.TP
+.B ERRNO
+If a system error occurs either doing a redirection for
+.BR getline ,
+during a read for
+.BR getline ,
+or during a
+.BR close ,
+then
+.B ERRNO
+will contain
+a string describing the error.
+.TP
+.B FIELDWIDTHS
+A white-space separated list of fieldwidths.  When set,
+.I gawk
+parses the input into fields of fixed width, instead of using the
+value of the
+.B FS
+variable as the field separator.
+The fixed field width facility is still experimental; expect the
+semantics to change as
+.I gawk
+evolves over time.
+.TP
+.B FILENAME
+The name of the current input file.
+If no files are specified on the command line, the value of
+.B FILENAME
+is ``\-''.
+.TP
+.B FNR
+The input record number in the current input file.
+.TP
+.B FS
+The input field separator, a blank by default.
+.TP
+.B IGNORECASE
+Controls the case-sensitivity of all regular expression operations. If
+.B IGNORECASE
+has a non-zero value, then pattern matching in rules,
+field splitting with
+.BR FS ,
+regular expression
+matching with
+.B ~
+and
+.BR !~ ,
+and the
+.BR gsub() ,
+.BR index() ,
+.BR match() ,
+.BR split() ,
+and
+.B sub()
+pre-defined functions will all ignore case when doing regular expression
+operations.  Thus, if
+.B IGNORECASE
+is not equal to zero,
+.B /aB/
+matches all of the strings \fB"ab"\fP, \fB"aB"\fP, \fB"Ab"\fP,
+and \fB"AB"\fP.
+As with all AWK variables, the initial value of
+.B IGNORECASE
+is zero, so all regular expression operations are normally case-sensitive.
+.TP
+.B NF
+The number of fields in the current input record.
+.TP
+.B NR
+The total number of input records seen so far.
+.TP
+.B OFMT
+The output format for numbers, \fB"%.6g"\fR, by default.
+.TP
+.B OFS
+The output field separator, a blank by default.
+.TP
+.B ORS
+The output record separator, by default a newline.
+.TP
+.B RS
+The input record separator, by default a newline.
+.B RS
+is exceptional in that only the first character of its string
+value is used for separating records.
+(This will probably change in a future release of
+.IR gawk .)
+If
+.B RS
+is set to the null string, then records are separated by
+blank lines.
+When
+.B RS
+is set to the null string, then the newline character always acts as
+a field separator, in addition to whatever value
+.B FS
+may have.
+.TP
+.B RSTART
+The index of the first character matched by
+.BR match() ;
+0 if no match.
+.TP
+.B RLENGTH
+The length of the string matched by
+.BR match() ;
+\-1 if no match.
+.TP
+.B SUBSEP
+The character used to separate multiple subscripts in array
+elements, by default \fB"\e034"\fR.
+.SS Arrays
+.PP
+Arrays are subscripted with an expression between square brackets
+.RB ( [ " and " ] ).
+If the expression is an expression list
+.RI ( expr ", " expr " ...)"
+then the array subscript is a string consisting of the
+concatenation of the (string) value of each expression,
+separated by the value of the
+.B SUBSEP
+variable.
+This facility is used to simulate multiply dimensioned
+arrays. For example:
+.PP
+.RS
+.ft B
+i = "A" ;\^ j = "B" ;\^ k = "C"
+.br
+x[i, j, k] = "hello, world\en"
+.ft R
+.RE
+.PP
+assigns the string \fB"hello, world\en"\fR to the element of the array
+.B x
+which is indexed by the string \fB"A\e034B\e034C"\fR. All arrays in AWK
+are associative, i.e. indexed by string values.
+.PP
+The special operator
+.B in
+may be used in an
+.B if
+or
+.B while
+statement to see if an array has an index consisting of a particular
+value.
+.PP
+.RS
+.ft B
+.nf
+if (val in array)
+	print array[val]
+.fi
+.ft
+.RE
+.PP
+If the array has multiple subscripts, use
+.BR "(i, j) in array" .
+.PP
+The
+.B in
+construct may also be used in a
+.B for
+loop to iterate over all the elements of an array.
+.PP
+An element may be deleted from an array using the
+.B delete
+statement.
+.SS Variable Typing And Conversion
+.PP
+Variables and fields
+may be (floating point) numbers, or strings, or both. How the
+value of a variable is interpreted depends upon its context. If used in
+a numeric expression, it will be treated as a number, if used as a string
+it will be treated as a string.
+.PP
+To force a variable to be treated as a number, add 0 to it; to force it
+to be treated as a string, concatenate it with the null string.
+.PP
+When a string must be converted to a number, the conversion is accomplished
+using
+.IR atof (3).
+A number is converted to a string by using the value of
+.B CONVFMT
+as a format string for
+.IR sprintf (3),
+with the numeric value of the variable as the argument.
+However, even though all numbers in AWK are floating-point,
+integral values are
+.I always
+converted as integers.  Thus, given
+.PP
+.RS
+.ft B
+.nf
+CONVFMT = "%2.2f"
+a = 12
+b = a ""
+.fi
+.ft R
+.RE
+.PP
+the variable
+.B b
+has a value of \fB"12"\fR and not \fB"12.00"\fR.
+.PP
+.I Gawk
+performs comparisons as follows:
+If two variables are numeric, they are compared numerically.
+If one value is numeric and the other has a string value that is a
+``numeric string,'' then comparisons are also done numerically.
+Otherwise, the numeric value is converted to a string and a string
+comparison is performed.
+Two strings are compared, of course, as strings.
+According to the \*(PX standard, even if two strings are
+numeric strings, a numeric comparison is performed.  However, this is
+clearly incorrect, and
+.I gawk
+does not do this.
+.PP
+Uninitialized variables have the numeric value 0 and the string value ""
+(the null, or empty, string).
+.SH PATTERNS AND ACTIONS
+AWK is a line oriented language. The pattern comes first, and then the
+action. Action statements are enclosed in
+.B {
+and
+.BR } .
+Either the pattern may be missing, or the action may be missing, but,
+of course, not both. If the pattern is missing, the action will be
+executed for every single line of input.
+A missing action is equivalent to
+.RS
+.PP
+.B "{ print }"
+.RE
+.PP
+which prints the entire line.
+.PP
+Comments begin with the ``#'' character, and continue until the
+end of the line.
+Blank lines may be used to separate statements.
+Normally, a statement ends with a newline, however, this is not the
+case for lines ending in
+a ``,'', ``{'', ``?'', ``:'', ``&&'', or ``||''.
+Lines ending in
+.B do
+or
+.B else
+also have their statements automatically continued on the following line.
+In other cases, a line can be continued by ending it with a ``\e'',
+in which case the newline will be ignored.
+.PP
+Multiple statements may
+be put on one line by separating them with a ``;''.
+This applies to both the statements within the action part of a
+pattern-action pair (the usual case),
+and to the pattern-action statements themselves.
+.SS Patterns
+AWK patterns may be one of the following:
+.PP
+.RS
+.nf
+.B BEGIN
+.B END
+.BI / "regular expression" /
+.I "relational expression"
+.IB pattern " && " pattern
+.IB pattern " || " pattern
+.IB pattern " ? " pattern " : " pattern
+.BI ( pattern )
+.BI ! " pattern"
+.IB pattern1 ", " pattern2
+.fi
+.RE
+.PP
+.B BEGIN
+and
+.B END
+are two special kinds of patterns which are not tested against
+the input.
+The action parts of all
+.B BEGIN
+patterns are merged as if all the statements had
+been written in a single
+.B BEGIN
+block. They are executed before any
+of the input is read. Similarly, all the
+.B END
+blocks are merged,
+and executed when all the input is exhausted (or when an
+.B exit
+statement is executed).
+.B BEGIN
+and
+.B END
+patterns cannot be combined with other patterns in pattern expressions.
+.B BEGIN
+and
+.B END
+patterns cannot have missing action parts.
+.PP
+For
+.BI / "regular expression" /
+patterns, the associated statement is executed for each input line that matches
+the regular expression.
+Regular expressions are the same as those in
+.IR egrep (1),
+and are summarized below.
+.PP
+A
+.I "relational expression"
+may use any of the operators defined below in the section on actions.
+These generally test whether certain fields match certain regular expressions.
+.PP
+The
+.BR && ,
+.BR || ,
+and
+.B !
+operators are logical AND, logical OR, and logical NOT, respectively, as in C.
+They do short-circuit evaluation, also as in C, and are used for combining
+more primitive pattern expressions. As in most languages, parentheses
+may be used to change the order of evaluation.
+.PP
+The
+.B ?\^:
+operator is like the same operator in C. If the first pattern is true
+then the pattern used for testing is the second pattern, otherwise it is
+the third. Only one of the second and third patterns is evaluated.
+.PP
+The 
+.IB pattern1 ", " pattern2
+form of an expression is called a range pattern.
+It matches all input records starting with a line that matches
+.IR pattern1 ,
+and continuing until a record that matches
+.IR pattern2 ,
+inclusive. It does not combine with any other sort of pattern expression.
+.SS Regular Expressions
+Regular expressions are the extended kind found in
+.IR egrep .
+They are composed of characters as follows:
+.TP \w'\fB[^\fIabc...\fB]\fR'u+2n
+.I c
+matches the non-metacharacter
+.IR c .
+.TP
+.I \ec
+matches the literal character
+.IR c .
+.TP
+.B .
+matches any character except newline.
+.TP
+.B ^
+matches the beginning of a line or a string.
+.TP
+.B $
+matches the end of a line or a string.
+.TP
+.BI [ abc... ]
+character class, matches any of the characters
+.IR abc... .
+.TP
+.BI [^ abc... ]
+negated character class, matches any character except
+.I abc...
+and newline.
+.TP
+.IB r1 | r2
+alternation: matches either
+.I r1
+or
+.IR r2 .
+.TP
+.I r1r2
+concatenation: matches
+.IR r1 ,
+and then
+.IR r2 .
+.TP
+.IB r +
+matches one or more
+.IR r 's. 
+.TP
+.IB r *
+matches zero or more
+.IR r 's. 
+.TP
+.IB r ?
+matches zero or one
+.IR r 's. 
+.TP
+.BI ( r )
+grouping: matches
+.IR r .
+.PP
+The escape sequences that are valid in string constants (see below)
+are also legal in regular expressions.
+.SS Actions
+Action statements are enclosed in braces,
+.B {
+and
+.BR } .
+Action statements consist of the usual assignment, conditional, and looping
+statements found in most languages. The operators, control statements,
+and input/output statements
+available are patterned after those in C.
+.SS Operators
+.PP
+The operators in AWK, in order of increasing precedence, are
+.PP
+.TP "\w'\fB*= /= %= ^=\fR'u+1n"
+.PD 0
+.B "= += \-="
+.TP
+.PD
+.B "*= /= %= ^="
+Assignment. Both absolute assignment
+.BI ( var " = " value )
+and operator-assignment (the other forms) are supported.
+.TP
+.B ?:
+The C conditional expression. This has the form
+.IB expr1 " ? " expr2 " : " expr3\c
+\&. If
+.I expr1
+is true, the value of the expression is
+.IR expr2 ,
+otherwise it is
+.IR expr3 .
+Only one of
+.I expr2
+and
+.I expr3
+is evaluated.
+.TP
+.B ||
+Logical OR.
+.TP
+.B &&
+Logical AND.
+.TP
+.B "~ !~"
+Regular expression match, negated match.
+.B NOTE:
+Do not use a constant regular expression
+.RB ( /foo/ )
+on the left-hand side of a
+.B ~
+or
+.BR !~ .
+Only use one on the right-hand side.  The expression
+.BI "/foo/ ~ " exp
+has the same meaning as \fB(($0 ~ /foo/) ~ \fIexp\fB)\fR.
+This is usually
+.I not
+what was intended.
+.TP
+.PD 0
+.B "< >"
+.TP
+.PD 0
+.B "<= >="
+.TP
+.PD
+.B "!= =="
+The regular relational operators.
+.TP
+.I blank
+String concatenation.
+.TP
+.B "+ \-"
+Addition and subtraction.
+.TP
+.B "* / %"
+Multiplication, division, and modulus.
+.TP
+.B "+ \- !"
+Unary plus, unary minus, and logical negation.
+.TP
+.B ^
+Exponentiation (\fB**\fR may also be used, and \fB**=\fR for
+the assignment operator).
+.TP
+.B "++ \-\^\-"
+Increment and decrement, both prefix and postfix.
+.TP
+.B $
+Field reference.
+.SS Control Statements
+.PP
+The control statements are
+as follows:
+.PP
+.RS
+.nf
+\fBif (\fIcondition\fB) \fIstatement\fR [ \fBelse\fI statement \fR]
+\fBwhile (\fIcondition\fB) \fIstatement \fR
+\fBdo \fIstatement \fBwhile (\fIcondition\fB)\fR
+\fBfor (\fIexpr1\fB; \fIexpr2\fB; \fIexpr3\fB) \fIstatement\fR
+\fBfor (\fIvar \fBin\fI array\fB) \fIstatement\fR
+\fBbreak\fR
+\fBcontinue\fR
+\fBdelete \fIarray\^\fB[\^\fIindex\^\fB]\fR
+\fBexit\fR [ \fIexpression\fR ]
+\fB{ \fIstatements \fB}
+.fi
+.RE
+.SS "I/O Statements"
+.PP
+The input/output statements are as follows:
+.PP
+.TP "\w'\fBprintf \fIfmt, expr-list\fR'u+1n"
+.BI close( filename )
+Close file (or pipe, see below).
+.TP
+.B getline
+Set
+.B $0
+from next input record; set
+.BR NF ,
+.BR NR ,
+.BR FNR .
+.TP
+.BI "getline <" file
+Set
+.B $0
+from next record of
+.IR file ;
+set
+.BR NF .
+.TP
+.BI getline " var"
+Set
+.I var
+from next input record; set
+.BR NF ,
+.BR FNR .
+.TP
+.BI getline " var" " <" file
+Set
+.I var
+from next record of
+.IR file .
+.TP
+.B next
+Stop processing the current input record. The next input record
+is read and processing starts over with the first pattern in the
+AWK program. If the end of the input data is reached, the
+.B END
+block(s), if any, are executed.
+.TP
+.B "next file"
+Stop processing the current input file.  The next input record read
+comes from the next input file.
+.B FILENAME
+is updated,
+.B FNR
+is reset to 1, and processing starts over with the first pattern in the
+AWK program. If the end of the input data is reached, the
+.B END
+block(s), if any, are executed.
+.TP
+.B print
+Prints the current record.
+.TP
+.BI print " expr-list"
+Prints expressions.
+.TP
+.BI print " expr-list" " >" file
+Prints expressions on
+.IR file .
+.TP
+.BI printf " fmt, expr-list"
+Format and print.
+.TP
+.BI printf " fmt, expr-list" " >" file
+Format and print on
+.IR file .
+.TP
+.BI system( cmd-line )
+Execute the command
+.IR cmd-line ,
+and return the exit status.
+(This may not be available on non-\*(PX systems.)
+.PP
+Other input/output redirections are also allowed. For
+.B print
+and
+.BR printf ,
+.BI >> file
+appends output to the
+.IR file ,
+while
+.BI | " command"
+writes on a pipe.
+In a similar fashion,
+.IB command " | getline"
+pipes into
+.BR getline .
+.BR Getline
+will return 0 on end of file, and \-1 on an error.
+.SS The \fIprintf\fP\^ Statement
+.PP
+The AWK versions of the
+.B printf
+statement and
+.B sprintf()
+function
+(see below)
+accept the following conversion specification formats:
+.TP
+.B %c
+An \s-1ASCII\s+1 character.
+If the argument used for
+.B %c
+is numeric, it is treated as a character and printed.
+Otherwise, the argument is assumed to be a string, and the only first
+character of that string is printed.
+.TP
+.B %d
+A decimal number (the integer part).
+.TP
+.B %i
+Just like
+.BR %d .
+.TP
+.B %e
+A floating point number of the form
+.BR [\-]d.ddddddE[+\^\-]dd .
+.TP
+.B %f
+A floating point number of the form
+.BR [\-]ddd.dddddd .
+.TP
+.B %g
+Use
+.B e
+or
+.B f
+conversion, whichever is shorter, with nonsignificant zeros suppressed.
+.TP
+.B %o
+An unsigned octal number (again, an integer).
+.TP
+.B %s
+A character string.
+.TP
+.B %x
+An unsigned hexadecimal number (an integer).
+.TP
+.B %X
+Like
+.BR %x ,
+but using
+.B ABCDEF
+instead of
+.BR abcdef .
+.TP
+.B %%
+A single
+.B %
+character; no argument is converted.
+.PP
+There are optional, additional parameters that may lie between the
+.B %
+and the control letter:
+.TP
+.B \-
+The expression should be left-justified within its field.
+.TP
+.I width
+The field should be padded to this width. If the number has a leading
+zero, then the field will be padded with zeros.
+Otherwise it is padded with blanks.
+.TP
+.BI . prec
+A number indicating the maximum width of strings or digits to the right
+of the decimal point.
+.PP
+The dynamic
+.I width
+and
+.I prec
+capabilities of the \*(AN C
+.B printf()
+routines are supported.
+A
+.B *
+in place of either the
+.B width
+or
+.B prec
+specifications will cause their values to be taken from
+the argument list to
+.B printf
+or
+.BR sprintf() .
+.SS Special File Names
+.PP
+When doing I/O redirection from either
+.B print
+or
+.B printf
+into a file,
+or via
+.B getline
+from a file,
+.I gawk
+recognizes certain special filenames internally.  These filenames
+allow access to open file descriptors inherited from
+.IR gawk 's
+parent process (usually the shell).
+Other special filenames provide access information about the running
+.B gawk
+process.
+The filenames are:
+.TP \w'\fB/dev/stdout\fR'u+1n
+.B /dev/pid
+Reading this file returns the process ID of the current process,
+in decimal, terminated with a newline.
+.TP
+.B /dev/ppid
+Reading this file returns the parent process ID of the current process,
+in decimal, terminated with a newline.
+.TP
+.B /dev/pgrpid
+Reading this file returns the process group ID of the current process,
+in decimal, terminated with a newline.
+.TP
+.B /dev/user
+Reading this file returns a single record terminated with a newline.
+The fields are separated with blanks.
+.B $1
+is the value of the
+.IR getuid (2)
+system call,
+.B $2
+is the value of the
+.IR geteuid (2)
+system call,
+.B $3
+is the value of the
+.IR getgid (2)
+system call, and
+.B $4
+is the value of the
+.IR getegid (2)
+system call.
+If there are any additional fields, they are the group IDs returned by
+.IR getgroups (2).
+(Multiple groups may not be supported on all systems.)
+.TP
+.B /dev/stdin
+The standard input.
+.TP
+.B /dev/stdout
+The standard output.
+.TP
+.B /dev/stderr
+The standard error output.
+.TP
+.BI /dev/fd/\^ n
+The file associated with the open file descriptor
+.IR n .
+.PP
+These are particularly useful for error messages. For example:
+.PP
+.RS
+.ft B
+print "You blew it!" > "/dev/stderr"
+.ft R
+.RE
+.PP
+whereas you would otherwise have to use
+.PP
+.RS
+.ft B
+print "You blew it!" | "cat 1>&2"
+.ft R
+.RE
+.PP
+These file names may also be used on the command line to name data files.
+.SS Numeric Functions
+.PP
+AWK has the following pre-defined arithmetic functions:
+.PP
+.TP \w'\fBsrand(\^\fIexpr\^\fB)\fR'u+1n
+.BI atan2( y , " x" )
+returns the arctangent of
+.I y/x
+in radians.
+.TP
+.BI cos( expr )
+returns the cosine in radians.
+.TP
+.BI exp( expr )
+the exponential function.
+.TP
+.BI int( expr )
+truncates to integer.
+.TP
+.BI log( expr )
+the natural logarithm function.
+.TP
+.B rand()
+returns a random number between 0 and 1.
+.TP
+.BI sin( expr )
+returns the sine in radians.
+.TP
+.BI sqrt( expr )
+the square root function.
+.TP
+.BI srand( expr )
+use
+.I expr
+as a new seed for the random number generator. If no
+.I expr
+is provided, the time of day will be used.
+The return value is the previous seed for the random
+number generator.
+.SS String Functions
+.PP
+AWK has the following pre-defined string functions:
+.PP
+.TP "\w'\fBsprintf(\^\fIfmt\fB\^, \fIexpr-list\^\fB)\fR'u+1n"
+\fBgsub(\fIr\fB, \fIs\fB, \fIt\fB)\fR
+for each substring matching the regular expression
+.I r
+in the string
+.IR t ,
+substitute the string
+.IR s ,
+and return the number of substitutions.
+If
+.I t
+is not supplied, use
+.BR $0 .
+.TP
+.BI index( s , " t" )
+returns the index of the string
+.I t
+in the string
+.IR s ,
+or 0 if
+.I t
+is not present.
+.TP
+.BI length( s )
+returns the length of the string
+.IR s ,
+or the length of
+.B $0
+if
+.I s
+is not supplied.
+.TP
+.BI match( s , " r" )
+returns the position in
+.I s
+where the regular expression
+.I r
+occurs, or 0 if
+.I r
+is not present, and sets the values of
+.B RSTART
+and
+.BR RLENGTH .
+.TP
+\fBsplit(\fIs\fB, \fIa\fB, \fIr\fB)\fR
+splits the string
+.I s
+into the array
+.I a
+on the regular expression
+.IR r ,
+and returns the number of fields. If
+.I r
+is omitted,
+.B FS
+is used instead.
+.TP
+.BI sprintf( fmt , " expr-list" )
+prints
+.I expr-list
+according to
+.IR fmt ,
+and returns the resulting string.
+.TP
+\fBsub(\fIr\fB, \fIs\fB, \fIt\fB)\fR
+just like
+.BR gsub() ,
+but only the first matching substring is replaced.
+.TP
+\fBsubstr(\fIs\fB, \fIi\fB, \fIn\fB)\fR
+returns the
+.IR n -character
+substring of
+.I s
+starting at
+.IR i .
+If
+.I n
+is omitted, the rest of
+.I s
+is used.
+.TP
+.BI tolower( str )
+returns a copy of the string
+.IR str ,
+with all the upper-case characters in
+.I str
+translated to their corresponding lower-case counterparts.
+Non-alphabetic characters are left unchanged.
+.TP
+.BI toupper( str )
+returns a copy of the string
+.IR str ,
+with all the lower-case characters in
+.I str
+translated to their corresponding upper-case counterparts.
+Non-alphabetic characters are left unchanged.
+.SS Time Functions
+.PP
+Since one of the primary uses of AWK programs is processing log files
+that contain time stamp information,
+.I gawk
+provides the following two functions for obtaining time stamps and
+formatting them.
+.PP
+.TP "\w'\fBsystime()\fR'u+1n"
+.B systime()
+returns the current time of day as the number of seconds since the Epoch
+(Midnight UTC, January 1, 1970 on \*(PX systems).
+.TP
+\fBstrftime(\fIformat\fR, \fItimestamp\fB)\fR
+formats
+.I timestamp
+according to the specification in
+.IR format.
+The
+.I timestamp
+should be of the same form as returned by
+.BR systime() .
+If
+.I timestamp
+is missing, the current time of day is used.
+See the specification for the
+.B strftime()
+function in \*(AN C for the format conversions that are
+guaranteed to be available.
+A public-domain version of
+.IR strftime (3)
+and a man page for it are shipped with
+.IR gawk ;
+if that version was used to build
+.IR gawk ,
+then all of the conversions described in that man page are available to
+.IR gawk.
+.SS String Constants
+.PP
+String constants in AWK are sequences of characters enclosed
+between double quotes (\fB"\fR). Within strings, certain
+.I "escape sequences"
+are recognized, as in C. These are:
+.PP
+.TP \w'\fB\e\^\fIddd\fR'u+1n
+.B \e\e
+A literal backslash.
+.TP
+.B \ea
+The ``alert'' character; usually the \s-1ASCII\s+1 \s-1BEL\s+1 character.
+.TP
+.B \eb
+backspace.
+.TP
+.B \ef
+form-feed.
+.TP
+.B \en
+new line.
+.TP
+.B \er
+carriage return.
+.TP
+.B \et
+horizontal tab.
+.TP
+.B \ev
+vertical tab.
+.TP
+.BI \ex "\^hex digits"
+The character represented by the string of hexadecimal digits following
+the
+.BR \ex .
+As in \*(AN C, all following hexadecimal digits are considered part of
+the escape sequence.
+(This feature should tell us something about language design by committee.)
+E.g., "\ex1B" is the \s-1ASCII\s+1 \s-1ESC\s+1 (escape) character.
+.TP
+.BI \e ddd
+The character represented by the 1-, 2-, or 3-digit sequence of octal
+digits. E.g. "\e033" is the \s-1ASCII\s+1 \s-1ESC\s+1 (escape) character.
+.TP
+.BI \e c
+The literal character
+.IR c\^ .
+.PP
+The escape sequences may also be used inside constant regular expressions
+(e.g.,
+.B "/[\ \et\ef\en\er\ev]/"
+matches whitespace characters).
+.SH FUNCTIONS
+Functions in AWK are defined as follows:
+.PP
+.RS
+\fBfunction \fIname\fB(\fIparameter list\fB) { \fIstatements \fB}\fR
+.RE
+.PP
+Functions are executed when called from within the action parts of regular
+pattern-action statements. Actual parameters supplied in the function
+call are used to instantiate the formal parameters declared in the function.
+Arrays are passed by reference, other variables are passed by value.
+.PP
+Since functions were not originally part of the AWK language, the provision
+for local variables is rather clumsy: They are declared as extra parameters
+in the parameter list. The convention is to separate local variables from
+real parameters by extra spaces in the parameter list. For example:
+.PP
+.RS
+.ft B
+.nf
+function  f(p, q,     a, b) {	# a & b are local
+			..... }
+
+/abc/	{ ... ; f(1, 2) ; ... }
+.fi
+.ft R
+.RE
+.PP
+The left parenthesis in a function call is required
+to immediately follow the function name,
+without any intervening white space.
+This is to avoid a syntactic ambiguity with the concatenation operator.
+This restriction does not apply to the built-in functions listed above.
+.PP
+Functions may call each other and may be recursive.
+Function parameters used as local variables are initialized
+to the null string and the number zero upon function invocation.
+.PP
+The word
+.B func
+may be used in place of
+.BR function .
+.SH EXAMPLES
+.nf
+Print and sort the login names of all users:
+
+.ft B
+	BEGIN	{ FS = ":" }
+		{ print $1 | "sort" }
+
+.ft R
+Count lines in a file:
+
+.ft B
+		{ nlines++ }
+	END	{ print nlines }
+
+.ft R
+Precede each line by its number in the file:
+
+.ft B
+	{ print FNR, $0 }
+
+.ft R
+Concatenate and line number (a variation on a theme):
+
+.ft B
+	{ print NR, $0 }
+.ft R
+.fi
+.SH SEE ALSO
+.IR egrep (1)
+.PP
+.IR "The AWK Programming Language" ,
+Alfred V. Aho, Brian W. Kernighan, Peter J. Weinberger,
+Addison-Wesley, 1988. ISBN 0-201-07981-X.
+.PP
+.IR "The GAWK Manual" ,
+Edition 0.15, published by the Free Software Foundation, 1993.
+.SH POSIX COMPATIBILITY
+A primary goal for
+.I gawk
+is compatibility with the \*(PX standard, as well as with the
+latest version of \*(UX
+.IR awk .
+To this end,
+.I gawk
+incorporates the following user visible
+features which are not described in the AWK book,
+but are part of
+.I awk
+in System V Release 4, and are in the \*(PX standard.
+.PP
+The
+.B \-v
+option for assigning variables before program execution starts is new.
+The book indicates that command line variable assignment happens when
+.I awk
+would otherwise open the argument as a file, which is after the
+.B BEGIN
+block is executed.  However, in earlier implementations, when such an
+assignment appeared before any file names, the assignment would happen
+.I before
+the
+.B BEGIN
+block was run.  Applications came to depend on this ``feature.''
+When
+.I awk
+was changed to match its documentation, this option was added to
+accomodate applications that depended upon the old behavior.
+(This feature was agreed upon by both the AT&T and GNU developers.)
+.PP
+The
+.B \-W
+option for implementation specific features is from the \*(PX standard.
+.PP
+When processing arguments,
+.I gawk
+uses the special option ``\fB\-\^\-\fP'' to signal the end of
+arguments, and warns about, but otherwise ignores, undefined options.
+.PP
+The AWK book does not define the return value of
+.BR srand() .
+The System V Release 4 version of \*(UX
+.I awk
+(and the \*(PX standard)
+has it return the seed it was using, to allow keeping track
+of random number sequences. Therefore
+.B srand()
+in
+.I gawk
+also returns its current seed.
+.PP
+Other new features are:
+The use of multiple
+.B \-f
+options (from MKS
+.IR awk );
+the
+.B ENVIRON
+array; the
+.BR \ea ,
+and
+.BR \ev
+escape sequences (done originally in
+.I gawk
+and fed back into AT&T's); the
+.B tolower()
+and
+.B toupper()
+built-in functions (from AT&T); and the \*(AN C conversion specifications in
+.B printf
+(done first in AT&T's version).
+.SH GNU EXTENSIONS
+.I Gawk
+has some extensions to \*(PX
+.IR awk .
+They are described in this section.  All the extensions described here
+can be disabled by
+invoking
+.I gawk
+with the
+.B "\-W compat"
+option.
+.PP
+The following features of
+.I gawk
+are not available in
+\*(PX
+.IR awk .
+.RS
+.TP \w'\(bu'u+1n
+\(bu
+The
+.B \ex
+escape sequence.
+.TP
+\(bu
+The
+.B systime()
+and
+.B strftime()
+functions.
+.TP
+\(bu
+The special file names available for I/O redirection are not recognized.
+.TP
+\(bu
+The
+.B ARGIND
+and
+.B ERRNO
+variables are not special.
+.TP
+\(bu
+The
+.B IGNORECASE
+variable and its side-effects are not available.
+.TP
+\(bu
+The
+.B FIELDWIDTHS
+variable and fixed width field splitting.
+.TP
+\(bu
+No path search is performed for files named via the
+.B \-f
+option.  Therefore the
+.B AWKPATH
+environment variable is not special.
+.TP
+\(bu
+The use of
+.B "next file"
+to abandon processing of the current input file.
+.RE
+.PP
+The AWK book does not define the return value of the
+.B close()
+function.
+.IR Gawk\^ 's
+.B close()
+returns the value from
+.IR fclose (3),
+or
+.IR pclose (3),
+when closing a file or pipe, respectively.
+.PP
+When
+.I gawk
+is invoked with the
+.B "\-W compat"
+option,
+if the
+.I fs
+argument to the
+.B \-F
+option is ``t'', then
+.B FS
+will be set to the tab character.
+Since this is a rather ugly special case, it is not the default behavior.
+This behavior also does not occur if
+.B \-Wposix
+has been specified.
+.ig
+.PP
+If
+.I gawk
+was compiled for debugging, it will
+accept the following additional options:
+.TP
+.PD 0
+.B \-Wparsedebug
+.TP
+.PD
+.B \-\^\-parsedebug
+Turn on
+.IR yacc (1)
+or
+.IR bison (1)
+debugging output during program parsing.
+This option should only be of interest to the
+.I gawk
+maintainers, and may not even be compiled into
+.IR gawk .
+..
+.SH HISTORICAL FEATURES
+There are two features of historical AWK implementations that
+.I gawk
+supports.
+First, it is possible to call the
+.B length()
+built-in function not only with no argument, but even without parentheses!
+Thus,
+.RS
+.PP
+.ft B
+a = length
+.ft R
+.RE
+.PP
+is the same as either of
+.RS
+.PP
+.ft B
+a = length()
+.br
+a = length($0)
+.ft R
+.RE
+.PP
+This feature is marked as ``deprecated'' in the \*(PX standard, and
+.I gawk
+will issue a warning about its use if
+.B \-Wlint
+is specified on the command line.
+.PP
+The other feature is the use of the
+.B continue
+statement outside the body of a
+.BR while ,
+.BR for ,
+or
+.B do
+loop.  Traditional AWK implementations have treated such usage as
+equivalent to the
+.B next
+statement.
+.I Gawk
+will support this usage if
+.B \-Wposix
+has not been specified.
+.SH BUGS
+The
+.B \-F
+option is not necessary given the command line variable assignment feature;
+it remains only for backwards compatibility.
+.PP
+If your system actually has support for
+.B /dev/fd
+and the associated
+.BR /dev/stdin ,
+.BR /dev/stdout ,
+and
+.B /dev/stderr
+files, you may get different output from
+.I gawk
+than you would get on a system without those files.  When
+.I gawk
+interprets these files internally, it synchronizes output to the standard
+output with output to
+.BR /dev/stdout ,
+while on a system with those files, the output is actually to different
+open files.
+Caveat Emptor.
+.SH VERSION INFORMATION
+This man page documents
+.IR gawk ,
+version 2.15.
+.PP
+Starting with the 2.15 version of
+.IR gawk ,
+the
+.BR \-c ,
+.BR \-V ,
+.BR \-C ,
+.ig
+.BR \-D ,
+..
+.BR \-a ,
+and
+.B \-e
+options of the 2.11 version are no longer recognized.
+.SH AUTHORS
+The original version of \*(UX
+.I awk
+was designed and implemented by Alfred Aho,
+Peter Weinberger, and Brian Kernighan of AT&T Bell Labs. Brian Kernighan
+continues to maintain and enhance it.
+.PP
+Paul Rubin and Jay Fenlason,
+of the Free Software Foundation, wrote
+.IR gawk ,
+to be compatible with the original version of
+.I awk
+distributed in Seventh Edition \*(UX.
+John Woods contributed a number of bug fixes.
+David Trueman, with contributions
+from Arnold Robbins, made
+.I gawk
+compatible with the new version of \*(UX
+.IR awk .
+.PP
+The initial DOS port was done by Conrad Kwok and Scott Garfinkle.
+Scott Deifik is the current DOS maintainer.  Pat Rankin did the
+port to VMS, and Michal Jaegermann did the port to the Atari ST.
+.SH ACKNOWLEDGEMENTS
+Brian Kernighan of Bell Labs
+provided valuable assistance during testing and debugging.
+We thank him.
diff --git a/gnu/usr.bin/awk/awk.h b/gnu/usr.bin/awk/awk.h
new file mode 100644
index 000000000000..ca3997f11d4b
--- /dev/null
+++ b/gnu/usr.bin/awk/awk.h
@@ -0,0 +1,763 @@
+/*
+ * awk.h -- Definitions for gawk. 
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* ------------------------------ Includes ------------------------------ */
+#include <stdio.h>
+#include <limits.h>
+#include <ctype.h>
+#include <setjmp.h>
+#include <varargs.h>
+#include <time.h>
+#include <errno.h>
+#if !defined(errno) && !defined(MSDOS)
+extern int errno;
+#endif
+#ifdef __GNU_LIBRARY__
+#ifndef linux
+#include <signum.h>
+#endif
+#endif
+
+/* ----------------- System dependencies (with more includes) -----------*/
+
+#if !defined(VMS) || (!defined(VAXC) && !defined(__DECC))
+#include <sys/types.h>
+#include <sys/stat.h>
+#else	/* VMS w/ VAXC or DECC */
+#include <types.h>
+#include <stat.h>
+#include <file.h>	/* avoid <fcntl.h> in io.c */
+#endif
+
+#include <signal.h>
+
+#include "config.h"
+
+#ifdef __STDC__
+#define	P(s)	s
+#define MALLOC_ARG_T size_t
+#else
+#define	P(s)	()
+#define MALLOC_ARG_T unsigned
+#define volatile
+#define const
+#endif
+
+#ifndef SIGTYPE
+#define SIGTYPE	void
+#endif
+
+#ifdef SIZE_T_MISSING
+typedef unsigned int size_t;
+#endif
+
+#ifndef SZTC
+#define SZTC
+#define INTC
+#endif
+
+#ifdef STDC_HEADERS
+#include <stdlib.h>
+#include <string.h>
+#ifdef NeXT
+#include <libc.h>
+#undef atof
+#else
+#if defined(atarist) || defined(VMS)
+#include <unixlib.h>
+#else	/* atarist || VMS */
+#ifndef MSDOS
+#include <unistd.h>
+#endif	/* MSDOS */
+#endif	/* atarist || VMS */
+#endif	/* Next */
+#else	/* STDC_HEADERS */
+#include "protos.h"
+#endif	/* STDC_HEADERS */
+
+#if defined(ultrix) && !defined(Ultrix41)
+extern char * getenv P((char *name));
+extern double atof P((char *s));
+#endif
+
+#ifndef __GNUC__
+#ifdef sparc
+/* nasty nasty SunOS-ism */
+#include <alloca.h>
+#ifdef lint
+extern char *alloca();
+#endif
+#else /* not sparc */
+#if !defined(alloca) && !defined(ALLOCA_PROTO)
+extern char *alloca();
+#endif
+#endif /* sparc */
+#endif /* __GNUC__ */
+
+#ifdef HAVE_UNDERSCORE_SETJMP
+/* nasty nasty berkelixm */
+#define setjmp	_setjmp
+#define longjmp	_longjmp
+#endif
+
+/*
+ * if you don't have vprintf, try this and cross your fingers.
+ */
+#if defined(VPRINTF_MISSING)
+#define vfprintf(fp,fmt,arg)	_doprnt((fmt), (arg), (fp))
+#endif
+
+#ifdef VMS
+/* some macros to redirect to code in vms/vms_misc.c */
+#define exit		vms_exit
+#define open		vms_open
+#define strerror	vms_strerror
+#define strdup		vms_strdup
+extern void  exit P((int));
+extern int   open P((const char *,int,...));
+extern char *strerror P((int));
+extern char *strdup P((const char *str));
+extern int   vms_devopen P((const char *,int));
+# ifndef NO_TTY_FWRITE
+#define fwrite		tty_fwrite
+#define fclose		tty_fclose
+extern size_t fwrite P((const void *,size_t,size_t,FILE *));
+extern int    fclose P((FILE *));
+# endif
+extern FILE *popen P((const char *,const char *));
+extern int   pclose P((FILE *));
+extern void vms_arg_fixup P((int *,char ***));
+/* some things not in STDC_HEADERS */
+extern int gnu_strftime P((char *,size_t,const char *,const struct tm *));
+extern int unlink P((const char *));
+extern int getopt P((int,char **,char *));
+extern int isatty P((int));
+#ifndef fileno
+extern int fileno P((FILE *));
+#endif
+extern int close(), dup(), dup2(), fstat(), read(), stat();
+#endif  /*VMS*/
+
+#ifdef MSDOS
+#include <io.h>
+extern FILE *popen P((char *, char *));
+extern int   pclose P((FILE *));
+#endif
+
+#define	GNU_REGEX
+#ifdef GNU_REGEX
+#include "regex.h"
+#include "dfa.h"
+typedef struct Regexp {
+	struct re_pattern_buffer pat;
+	struct re_registers regs;
+	struct regexp dfareg;
+	int dfa;
+} Regexp;
+#define	RESTART(rp,s)	(rp)->regs.start[0]
+#define	REEND(rp,s)	(rp)->regs.end[0]
+#else	/* GNU_REGEX */
+#endif	/* GNU_REGEX */
+
+#ifdef atarist
+#define read _text_read /* we do not want all these CR's to mess our input */
+extern int _text_read (int, char *, int);
+#endif
+
+#ifndef DEFPATH
+#define DEFPATH	".:/usr/local/lib/awk:/usr/lib/awk"
+#endif
+
+#ifndef ENVSEP
+#define ENVSEP	':'
+#endif
+
+/* ------------------ Constants, Structures, Typedefs  ------------------ */
+#define AWKNUM	double
+
+typedef enum {
+	/* illegal entry == 0 */
+	Node_illegal,
+
+	/* binary operators  lnode and rnode are the expressions to work on */
+	Node_times,
+	Node_quotient,
+	Node_mod,
+	Node_plus,
+	Node_minus,
+	Node_cond_pair,		/* conditional pair (see Node_line_range) */
+	Node_subscript,
+	Node_concat,
+	Node_exp,
+
+	/* unary operators   subnode is the expression to work on */
+/*10*/	Node_preincrement,
+	Node_predecrement,
+	Node_postincrement,
+	Node_postdecrement,
+	Node_unary_minus,
+	Node_field_spec,
+
+	/* assignments   lnode is the var to assign to, rnode is the exp */
+	Node_assign,
+	Node_assign_times,
+	Node_assign_quotient,
+	Node_assign_mod,
+/*20*/	Node_assign_plus,
+	Node_assign_minus,
+	Node_assign_exp,
+
+	/* boolean binaries   lnode and rnode are expressions */
+	Node_and,
+	Node_or,
+
+	/* binary relationals   compares lnode and rnode */
+	Node_equal,
+	Node_notequal,
+	Node_less,
+	Node_greater,
+	Node_leq,
+/*30*/	Node_geq,
+	Node_match,
+	Node_nomatch,
+
+	/* unary relationals   works on subnode */
+	Node_not,
+
+	/* program structures */
+	Node_rule_list,		/* lnode is a rule, rnode is rest of list */
+	Node_rule_node,		/* lnode is pattern, rnode is statement */
+	Node_statement_list,	/* lnode is statement, rnode is more list */
+	Node_if_branches,	/* lnode is to run on true, rnode on false */
+	Node_expression_list,	/* lnode is an exp, rnode is more list */
+	Node_param_list,	/* lnode is a variable, rnode is more list */
+
+	/* keywords */
+/*40*/	Node_K_if,		/* lnode is conditonal, rnode is if_branches */
+	Node_K_while,		/* lnode is condtional, rnode is stuff to run */
+	Node_K_for,		/* lnode is for_struct, rnode is stuff to run */
+	Node_K_arrayfor,	/* lnode is for_struct, rnode is stuff to run */
+	Node_K_break,		/* no subs */
+	Node_K_continue,	/* no stuff */
+	Node_K_print,		/* lnode is exp_list, rnode is redirect */
+	Node_K_printf,		/* lnode is exp_list, rnode is redirect */
+	Node_K_next,		/* no subs */
+	Node_K_exit,		/* subnode is return value, or NULL */
+/*50*/	Node_K_do,		/* lnode is conditional, rnode stuff to run */
+	Node_K_return,
+	Node_K_delete,
+	Node_K_getline,
+	Node_K_function,	/* lnode is statement list, rnode is params */
+
+	/* I/O redirection for print statements */
+	Node_redirect_output,	/* subnode is where to redirect */
+	Node_redirect_append,	/* subnode is where to redirect */
+	Node_redirect_pipe,	/* subnode is where to redirect */
+	Node_redirect_pipein,	/* subnode is where to redirect */
+	Node_redirect_input,	/* subnode is where to redirect */
+
+	/* Variables */
+/*60*/	Node_var,		/* rnode is value, lnode is array stuff */
+	Node_var_array,		/* array is ptr to elements, asize num of
+				 * eles */
+	Node_val,		/* node is a value - type in flags */
+
+	/* Builtins   subnode is explist to work on, proc is func to call */
+	Node_builtin,
+
+	/*
+	 * pattern: conditional ',' conditional ;  lnode of Node_line_range
+	 * is the two conditionals (Node_cond_pair), other word (rnode place)
+	 * is a flag indicating whether or not this range has been entered.
+	 */
+	Node_line_range,
+
+	/*
+	 * boolean test of membership in array lnode is string-valued
+	 * expression rnode is array name 
+	 */
+	Node_in_array,
+
+	Node_func,		/* lnode is param. list, rnode is body */
+	Node_func_call,		/* lnode is name, rnode is argument list */
+
+	Node_cond_exp,		/* lnode is conditonal, rnode is if_branches */
+	Node_regex,
+/*70*/	Node_hashnode,
+	Node_ahash,
+	Node_NF,
+	Node_NR,
+	Node_FNR,
+	Node_FS,
+	Node_RS,
+	Node_FIELDWIDTHS,
+	Node_IGNORECASE,
+	Node_OFS,
+	Node_ORS,
+	Node_OFMT,
+	Node_CONVFMT,
+	Node_K_nextfile
+} NODETYPE;
+
+/*
+ * NOTE - this struct is a rather kludgey -- it is packed to minimize
+ * space usage, at the expense of cleanliness.  Alter at own risk.
+ */
+typedef struct exp_node {
+	union {
+		struct {
+			union {
+				struct exp_node *lptr;
+				char *param_name;
+			} l;
+			union {
+				struct exp_node *rptr;
+				struct exp_node *(*pptr) ();
+				Regexp *preg;
+				struct for_loop_header *hd;
+				struct exp_node **av;
+				int r_ent;	/* range entered */
+			} r;
+			union {
+				char *name;
+				struct exp_node *extra;
+			} x;
+			short number;
+			unsigned char reflags;
+#			define	CASE	1
+#			define	CONST	2
+#			define	FS_DFLT	4
+		} nodep;
+		struct {
+			AWKNUM fltnum;	/* this is here for optimal packing of
+					 * the structure on many machines
+					 */
+			char *sp;
+			size_t slen;
+			unsigned char sref;
+			char idx;
+		} val;
+		struct {
+			struct exp_node *next;
+			char *name;
+			int length;
+			struct exp_node *value;
+		} hash;
+#define	hnext	sub.hash.next
+#define	hname	sub.hash.name
+#define	hlength	sub.hash.length
+#define	hvalue	sub.hash.value
+		struct {
+			struct exp_node *next;
+			struct exp_node *name;
+			struct exp_node *value;
+		} ahash;
+#define	ahnext	sub.ahash.next
+#define	ahname	sub.ahash.name
+#define	ahvalue	sub.ahash.value
+	} sub;
+	NODETYPE type;
+	unsigned short flags;
+#			define	MALLOC	1	/* can be free'd */
+#			define	TEMP	2	/* should be free'd */
+#			define	PERM	4	/* can't be free'd */
+#			define	STRING	8	/* assigned as string */
+#			define	STR	16	/* string value is current */
+#			define	NUM	32	/* numeric value is current */
+#			define	NUMBER	64	/* assigned as number */
+#			define	MAYBE_NUM 128	/* user input:  if NUMERIC then
+						 * a NUMBER
+						 */
+	char *vname;	/* variable's name */
+} NODE;
+
+#define lnode	sub.nodep.l.lptr
+#define nextp	sub.nodep.l.lptr
+#define rnode	sub.nodep.r.rptr
+#define source_file	sub.nodep.x.name
+#define	source_line	sub.nodep.number
+#define	param_cnt	sub.nodep.number
+#define param	sub.nodep.l.param_name
+
+#define subnode	lnode
+#define proc	sub.nodep.r.pptr
+
+#define re_reg	sub.nodep.r.preg
+#define re_flags sub.nodep.reflags
+#define re_text lnode
+#define re_exp	sub.nodep.x.extra
+#define	re_cnt	sub.nodep.number
+
+#define forsub	lnode
+#define forloop	rnode->sub.nodep.r.hd
+
+#define stptr	sub.val.sp
+#define stlen	sub.val.slen
+#define stref	sub.val.sref
+#define	stfmt	sub.val.idx
+
+#define numbr	sub.val.fltnum
+
+#define var_value lnode
+#define var_array sub.nodep.r.av
+
+#define condpair lnode
+#define triggered sub.nodep.r.r_ent
+
+#ifdef DONTDEF
+int primes[] = {31, 61, 127, 257, 509, 1021, 2053, 4099, 8191, 16381};
+#endif
+/* a quick profile suggests that the following is a good value */
+#define	HASHSIZE	127
+
+typedef struct for_loop_header {
+	NODE *init;
+	NODE *cond;
+	NODE *incr;
+} FOR_LOOP_HEADER;
+
+/* for "for(iggy in foo) {" */
+struct search {
+	NODE **arr_ptr;
+	NODE **arr_end;
+	NODE *bucket;
+	NODE *retval;
+};
+
+/* for faster input, bypass stdio */
+typedef struct iobuf {
+	int fd;
+	char *buf;
+	char *off;
+	char *end;
+	size_t size;	/* this will be determined by an fstat() call */
+	int cnt;
+	long secsiz;
+	int flag;
+#	define		IOP_IS_TTY	1
+#	define		IOP_IS_INTERNAL	2
+#	define		IOP_NO_FREE	4
+} IOBUF;
+
+typedef void (*Func_ptr)();
+
+/*
+ * structure used to dynamically maintain a linked-list of open files/pipes
+ */
+struct redirect {
+	unsigned int flag;
+#		define		RED_FILE	1
+#		define		RED_PIPE	2
+#		define		RED_READ	4
+#		define		RED_WRITE	8
+#		define		RED_APPEND	16
+#		define		RED_NOBUF	32
+#		define		RED_USED	64
+#		define		RED_EOF		128
+	char *value;
+	FILE *fp;
+	IOBUF *iop;
+	int pid;
+	int status;
+	struct redirect *prev;
+	struct redirect *next;
+};
+
+/* structure for our source, either a command line string or a source file */
+struct src {
+	enum srctype { CMDLINE = 1, SOURCEFILE } stype;
+	char *val;
+};
+
+/* longjmp return codes, must be nonzero */
+/* Continue means either for loop/while continue, or next input record */
+#define TAG_CONTINUE 1
+/* Break means either for/while break, or stop reading input */
+#define TAG_BREAK 2
+/* Return means return from a function call; leave value in ret_node */
+#define	TAG_RETURN 3
+
+#define HUGE    INT_MAX 
+
+/* -------------------------- External variables -------------------------- */
+/* gawk builtin variables */
+extern int NF;
+extern int NR;
+extern int FNR;
+extern int IGNORECASE;
+extern char *RS;
+extern char *OFS;
+extern int OFSlen;
+extern char *ORS;
+extern int ORSlen;
+extern char *OFMT;
+extern char *CONVFMT;
+extern int CONVFMTidx;
+extern int OFMTidx;
+extern NODE *FS_node, *NF_node, *RS_node, *NR_node;
+extern NODE *FILENAME_node, *OFS_node, *ORS_node, *OFMT_node;
+extern NODE *CONVFMT_node;
+extern NODE *FNR_node, *RLENGTH_node, *RSTART_node, *SUBSEP_node;
+extern NODE *IGNORECASE_node;
+extern NODE *FIELDWIDTHS_node;
+
+extern NODE **stack_ptr;
+extern NODE *Nnull_string;
+extern NODE **fields_arr;
+extern int sourceline;
+extern char *source;
+extern NODE *expression_value;
+
+extern NODE *_t;	/* used as temporary in tree_eval */
+
+extern const char *myname;
+
+extern NODE *nextfree;
+extern int field0_valid;
+extern int do_unix;
+extern int do_posix;
+extern int do_lint;
+extern int in_begin_rule;
+extern int in_end_rule;
+
+/* ------------------------- Pseudo-functions ------------------------- */
+
+#define is_identchar(c) (isalnum(c) || (c) == '_')
+
+
+#ifndef MPROF
+#define	getnode(n)	if (nextfree) n = nextfree, nextfree = nextfree->nextp;\
+			else n = more_nodes()
+#define	freenode(n)	((n)->nextp = nextfree, nextfree = (n))
+#else
+#define	getnode(n)	emalloc(n, NODE *, sizeof(NODE), "getnode")
+#define	freenode(n)	free(n)
+#endif
+
+#ifdef DEBUG
+#define	tree_eval(t)	r_tree_eval(t)
+#else
+#define	tree_eval(t)	(_t = (t),(_t) == NULL ? Nnull_string : \
+			((_t)->type == Node_val ? (_t) : \
+			((_t)->type == Node_var ? (_t)->var_value : \
+			((_t)->type == Node_param_list ? \
+			(stack_ptr[(_t)->param_cnt])->var_value : \
+			r_tree_eval((_t))))))
+#endif
+
+#define	make_number(x)	mk_number((x), (MALLOC|NUM|NUMBER))
+#define	tmp_number(x)	mk_number((x), (MALLOC|TEMP|NUM|NUMBER))
+
+#define	free_temp(n)	do {if ((n)->flags&TEMP) { unref(n); }} while (0)
+#define	make_string(s,l)	make_str_node((s), SZTC (l),0)
+#define		SCAN			1
+#define		ALREADY_MALLOCED	2
+
+#define	cant_happen()	fatal("internal error line %d, file: %s", \
+				__LINE__, __FILE__);
+
+#if defined(__STDC__) && !defined(NO_TOKEN_PASTING)
+#define	emalloc(var,ty,x,str)	(void)((var=(ty)malloc((MALLOC_ARG_T)(x))) ||\
+				 (fatal("%s: %s: can't allocate memory (%s)",\
+					(str), #var, strerror(errno)),0))
+#define	erealloc(var,ty,x,str)	(void)((var=(ty)realloc((char *)var,\
+						  (MALLOC_ARG_T)(x))) ||\
+				 (fatal("%s: %s: can't allocate memory (%s)",\
+					(str), #var, strerror(errno)),0))
+#else /* __STDC__ */
+#define	emalloc(var,ty,x,str)	(void)((var=(ty)malloc((MALLOC_ARG_T)(x))) ||\
+				 (fatal("%s: %s: can't allocate memory (%s)",\
+					(str), "var", strerror(errno)),0))
+#define	erealloc(var,ty,x,str)	(void)((var=(ty)realloc((char *)var,\
+						  (MALLOC_ARG_T)(x))) ||\
+				 (fatal("%s: %s: can't allocate memory (%s)",\
+					(str), "var", strerror(errno)),0))
+#endif /* __STDC__ */
+
+#ifdef DEBUG
+#define	force_number	r_force_number
+#define	force_string	r_force_string
+#else /* not DEBUG */
+#ifdef lint
+extern AWKNUM force_number();
+#endif
+#ifdef MSDOS
+extern double _msc51bug;
+#define	force_number(n)	(_msc51bug=(_t = (n),(_t->flags & NUM) ? _t->numbr : r_force_number(_t)))
+#else /* not MSDOS */
+#define	force_number(n)	(_t = (n),(_t->flags & NUM) ? _t->numbr : r_force_number(_t))
+#endif /* MSDOS */
+#define	force_string(s)	(_t = (s),(_t->flags & STR) ? _t : r_force_string(_t))
+#endif /* not DEBUG */
+
+#define	STREQ(a,b)	(*(a) == *(b) && strcmp((a), (b)) == 0)
+#define	STREQN(a,b,n)	((n)&& *(a)== *(b) && strncmp((a), (b), SZTC (n)) == 0)
+
+/* ------------- Function prototypes or defs (as appropriate) ------------- */
+
+/* array.c */
+extern NODE *concat_exp P((NODE *tree));
+extern void assoc_clear P((NODE *symbol));
+extern unsigned int hash P((char *s, int len));
+extern int in_array P((NODE *symbol, NODE *subs));
+extern NODE **assoc_lookup P((NODE *symbol, NODE *subs));
+extern void do_delete P((NODE *symbol, NODE *tree));
+extern void assoc_scan P((NODE *symbol, struct search *lookat));
+extern void assoc_next P((struct search *lookat));
+/* awk.tab.c */
+extern char *tokexpand P((void));
+extern char nextc P((void));
+extern NODE *node P((NODE *left, NODETYPE op, NODE *right));
+extern NODE *install P((char *name, NODE *value));
+extern NODE *lookup P((char *name));
+extern NODE *variable P((char *name, int can_free));
+extern int yyparse P((void));
+/* builtin.c */
+extern NODE *do_exp P((NODE *tree));
+extern NODE *do_index P((NODE *tree));
+extern NODE *do_int P((NODE *tree));
+extern NODE *do_length P((NODE *tree));
+extern NODE *do_log P((NODE *tree));
+extern NODE *do_sprintf P((NODE *tree));
+extern void do_printf P((NODE *tree));
+extern void print_simple P((NODE *tree, FILE *fp));
+extern NODE *do_sqrt P((NODE *tree));
+extern NODE *do_substr P((NODE *tree));
+extern NODE *do_strftime P((NODE *tree));
+extern NODE *do_systime P((NODE *tree));
+extern NODE *do_system P((NODE *tree));
+extern void do_print P((NODE *tree));
+extern NODE *do_tolower P((NODE *tree));
+extern NODE *do_toupper P((NODE *tree));
+extern NODE *do_atan2 P((NODE *tree));
+extern NODE *do_sin P((NODE *tree));
+extern NODE *do_cos P((NODE *tree));
+extern NODE *do_rand P((NODE *tree));
+extern NODE *do_srand P((NODE *tree));
+extern NODE *do_match P((NODE *tree));
+extern NODE *do_gsub P((NODE *tree));
+extern NODE *do_sub P((NODE *tree));
+/* eval.c */
+extern int interpret P((NODE *volatile tree));
+extern NODE *r_tree_eval P((NODE *tree));
+extern int cmp_nodes P((NODE *t1, NODE *t2));
+extern NODE **get_lhs P((NODE *ptr, Func_ptr *assign));
+extern void set_IGNORECASE P((void));
+void set_OFS P((void));
+void set_ORS P((void));
+void set_OFMT P((void));
+void set_CONVFMT P((void));
+/* field.c */
+extern void init_fields P((void));
+extern void set_record P((char *buf, int cnt, int freeold));
+extern void reset_record P((void));
+extern void set_NF P((void));
+extern NODE **get_field P((int num, Func_ptr *assign));
+extern NODE *do_split P((NODE *tree));
+extern void set_FS P((void));
+extern void set_RS P((void));
+extern void set_FIELDWIDTHS P((void));
+/* io.c */
+extern void set_FNR P((void));
+extern void set_NR P((void));
+extern void do_input P((void));
+extern struct redirect *redirect P((NODE *tree, int *errflg));
+extern NODE *do_close P((NODE *tree));
+extern int flush_io P((void));
+extern int close_io P((void));
+extern int devopen P((char *name, char *mode));
+extern int pathopen P((char *file));
+extern NODE *do_getline P((NODE *tree));
+extern void do_nextfile P((void));
+/* iop.c */
+extern int optimal_bufsize P((int fd));
+extern IOBUF *iop_alloc P((int fd));
+extern int get_a_record P((char **out, IOBUF *iop, int rs, int *errcode));
+/* main.c */
+extern int main P((int argc, char **argv));
+extern Regexp *mk_re_parse P((char *s, int ignorecase));
+extern void load_environ P((void));
+extern char *arg_assign P((char *arg));
+extern SIGTYPE catchsig P((int sig, int code));
+/* msg.c */
+#ifdef MSDOS
+extern void err P((char *s, char *emsg, char *va_list, ...));
+extern void msg P((char *va_alist, ...));
+extern void warning P((char *va_alist, ...));
+extern void fatal P((char *va_alist, ...));
+#else
+extern void err ();
+extern void msg ();
+extern void warning ();
+extern void fatal ();
+#endif
+/* node.c */
+extern AWKNUM r_force_number P((NODE *n));
+extern NODE *r_force_string P((NODE *s));
+extern NODE *dupnode P((NODE *n));
+extern NODE *mk_number P((AWKNUM x, unsigned int flags));
+extern NODE *make_str_node P((char *s, size_t len, int scan ));
+extern NODE *tmp_string P((char *s, size_t len ));
+extern NODE *more_nodes P((void));
+#ifdef DEBUG
+extern void freenode P((NODE *it));
+#endif
+extern void unref P((NODE *tmp));
+extern int parse_escape P((char **string_ptr));
+/* re.c */
+extern Regexp *make_regexp P((char *s, int len, int ignorecase, int dfa));
+extern int research P((Regexp *rp, char *str, int start, int len, int need_start));
+extern void refree P((Regexp *rp));
+extern void reg_error P((const char *s));
+extern Regexp *re_update P((NODE *t));
+extern void resyntax P((int syntax));
+extern void resetup P((void));
+
+/* strcase.c */
+extern int strcasecmp P((const char *s1, const char *s2));
+extern int strncasecmp P((const char *s1, const char *s2, register size_t n));
+
+#ifdef atarist
+/* atari/tmpnam.c */
+extern char *tmpnam P((char *buf));
+extern char *tempnam P((const char *path, const char *base));
+#endif
+
+/* Figure out what '\a' really is. */
+#ifdef __STDC__
+#define BELL	'\a'		/* sure makes life easy, don't it? */
+#else
+#	if 'z' - 'a' == 25	/* ascii */
+#		if 'a' != 97	/* machine is dumb enough to use mark parity */
+#			define BELL	'\207'
+#		else
+#			define BELL	'\07'
+#		endif
+#	else
+#		define BELL	'\057'
+#	endif
+#endif
+
+extern char casetable[];	/* for case-independent regexp matching */
diff --git a/gnu/usr.bin/awk/awk.y b/gnu/usr.bin/awk/awk.y
new file mode 100644
index 000000000000..6e87f1c449cc
--- /dev/null
+++ b/gnu/usr.bin/awk/awk.y
@@ -0,0 +1,1804 @@
+/*
+ * awk.y --- yacc/bison parser
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+%{
+#ifdef DEBUG
+#define YYDEBUG 12
+#endif
+
+#include "awk.h"
+
+static void yyerror (); /* va_alist */
+static char *get_src_buf P((void));
+static int yylex P((void));
+static NODE *node_common P((NODETYPE op));
+static NODE *snode P((NODE *subn, NODETYPE op, int sindex));
+static NODE *mkrangenode P((NODE *cpair));
+static NODE *make_for_loop P((NODE *init, NODE *cond, NODE *incr));
+static NODE *append_right P((NODE *list, NODE *new));
+static void func_install P((NODE *params, NODE *def));
+static void pop_var P((NODE *np, int freeit));
+static void pop_params P((NODE *params));
+static NODE *make_param P((char *name));
+static NODE *mk_rexp P((NODE *exp));
+
+static int want_assign;		/* lexical scanning kludge */
+static int want_regexp;		/* lexical scanning kludge */
+static int can_return;		/* lexical scanning kludge */
+static int io_allowed = 1;	/* lexical scanning kludge */
+static char *lexptr;		/* pointer to next char during parsing */
+static char *lexend;
+static char *lexptr_begin;	/* keep track of where we were for error msgs */
+static char *lexeme;		/* beginning of lexeme for debugging */
+static char *thisline = NULL;
+#define YYDEBUG_LEXER_TEXT (lexeme)
+static int param_counter;
+static char *tokstart = NULL;
+static char *token = NULL;
+static char *tokend;
+
+NODE *variables[HASHSIZE];
+
+extern char *source;
+extern int sourceline;
+extern struct src *srcfiles;
+extern int numfiles;
+extern int errcount;
+extern NODE *begin_block;
+extern NODE *end_block;
+%}
+
+%union {
+	long lval;
+	AWKNUM fval;
+	NODE *nodeval;
+	NODETYPE nodetypeval;
+	char *sval;
+	NODE *(*ptrval)();
+}
+
+%type <nodeval> function_prologue function_body
+%type <nodeval> rexp exp start program rule simp_exp
+%type <nodeval> non_post_simp_exp
+%type <nodeval> pattern 
+%type <nodeval>	action variable param_list
+%type <nodeval>	rexpression_list opt_rexpression_list
+%type <nodeval>	expression_list opt_expression_list
+%type <nodeval>	statements statement if_statement opt_param_list 
+%type <nodeval> opt_exp opt_variable regexp 
+%type <nodeval> input_redir output_redir
+%type <nodetypeval> print
+%type <sval> func_name
+%type <lval> lex_builtin
+
+%token <sval> FUNC_CALL NAME REGEXP
+%token <lval> ERROR
+%token <nodeval> YNUMBER YSTRING
+%token <nodetypeval> RELOP APPEND_OP
+%token <nodetypeval> ASSIGNOP MATCHOP NEWLINE CONCAT_OP
+%token <nodetypeval> LEX_BEGIN LEX_END LEX_IF LEX_ELSE LEX_RETURN LEX_DELETE
+%token <nodetypeval> LEX_WHILE LEX_DO LEX_FOR LEX_BREAK LEX_CONTINUE
+%token <nodetypeval> LEX_PRINT LEX_PRINTF LEX_NEXT LEX_EXIT LEX_FUNCTION
+%token <nodetypeval> LEX_GETLINE
+%token <nodetypeval> LEX_IN
+%token <lval> LEX_AND LEX_OR INCREMENT DECREMENT
+%token <lval> LEX_BUILTIN LEX_LENGTH
+
+/* these are just yylval numbers */
+
+/* Lowest to highest */
+%right ASSIGNOP
+%right '?' ':'
+%left LEX_OR
+%left LEX_AND
+%left LEX_GETLINE
+%nonassoc LEX_IN
+%left FUNC_CALL LEX_BUILTIN LEX_LENGTH
+%nonassoc MATCHOP
+%nonassoc RELOP '<' '>' '|' APPEND_OP
+%left CONCAT_OP
+%left YSTRING YNUMBER
+%left '+' '-'
+%left '*' '/' '%'
+%right '!' UNARY
+%right '^'
+%left INCREMENT DECREMENT
+%left '$'
+%left '(' ')'
+%%
+
+start
+	: opt_nls program opt_nls
+		{ expression_value = $2; }
+	;
+
+program
+	: rule
+		{ 
+			if ($1 != NULL)
+				$$ = $1;
+			else
+				$$ = NULL;
+			yyerrok;
+		}
+	| program rule
+		/* add the rule to the tail of list */
+		{
+			if ($2 == NULL)
+				$$ = $1;
+			else if ($1 == NULL)
+				$$ = $2;
+			else {
+				if ($1->type != Node_rule_list)
+					$1 = node($1, Node_rule_list,
+						(NODE*)NULL);
+				$$ = append_right ($1,
+				   node($2, Node_rule_list,(NODE *) NULL));
+			}
+			yyerrok;
+		}
+	| error	{ $$ = NULL; }
+	| program error { $$ = NULL; }
+	;
+
+rule
+	: LEX_BEGIN { io_allowed = 0; }
+	  action
+	  {
+		if (begin_block) {
+			if (begin_block->type != Node_rule_list)
+				begin_block = node(begin_block, Node_rule_list,
+					(NODE *)NULL);
+			(void) append_right (begin_block, node(
+			    node((NODE *)NULL, Node_rule_node, $3),
+			    Node_rule_list, (NODE *)NULL) );
+		} else
+			begin_block = node((NODE *)NULL, Node_rule_node, $3);
+		$$ = NULL;
+		io_allowed = 1;
+		yyerrok;
+	  }
+	| LEX_END { io_allowed = 0; }
+	  action
+	  {
+		if (end_block) {
+			if (end_block->type != Node_rule_list)
+				end_block = node(end_block, Node_rule_list,
+					(NODE *)NULL);
+			(void) append_right (end_block, node(
+			    node((NODE *)NULL, Node_rule_node, $3),
+			    Node_rule_list, (NODE *)NULL));
+		} else
+			end_block = node((NODE *)NULL, Node_rule_node, $3);
+		$$ = NULL;
+		io_allowed = 1;
+		yyerrok;
+	  }
+	| LEX_BEGIN statement_term
+	  {
+		warning("BEGIN blocks must have an action part");
+		errcount++;
+		yyerrok;
+	  }
+	| LEX_END statement_term
+	  {
+		warning("END blocks must have an action part");
+		errcount++;
+		yyerrok;
+	  }
+	| pattern action
+		{ $$ = node ($1, Node_rule_node, $2); yyerrok; }
+	| action
+		{ $$ = node ((NODE *)NULL, Node_rule_node, $1); yyerrok; }
+	| pattern statement_term
+		{
+		  $$ = node ($1,
+			     Node_rule_node,
+			     node(node(node(make_number(0.0),
+					    Node_field_spec,
+					    (NODE *) NULL),
+					Node_expression_list,
+					(NODE *) NULL),
+				  Node_K_print,
+				  (NODE *) NULL));
+		  yyerrok;
+		}
+	| function_prologue function_body
+		{
+			func_install($1, $2);
+			$$ = NULL;
+			yyerrok;
+		}
+	;
+
+func_name
+	: NAME
+		{ $$ = $1; }
+	| FUNC_CALL
+		{ $$ = $1; }
+	| lex_builtin
+	  {
+		yyerror("%s() is a built-in function, it cannot be redefined",
+			tokstart);
+		errcount++;
+		/* yyerrok; */
+	  }
+	;
+
+lex_builtin
+	: LEX_BUILTIN
+	| LEX_LENGTH
+	;
+		
+function_prologue
+	: LEX_FUNCTION 
+		{
+			param_counter = 0;
+		}
+	  func_name '(' opt_param_list r_paren opt_nls
+		{
+			$$ = append_right(make_param($3), $5);
+			can_return = 1;
+		}
+	;
+
+function_body
+	: l_brace statements r_brace opt_semi
+	  {
+		$$ = $2;
+		can_return = 0;
+	  }
+	;
+
+
+pattern
+	: exp
+		{ $$ = $1; }
+	| exp comma exp
+		{ $$ = mkrangenode ( node($1, Node_cond_pair, $3) ); }
+	;
+
+regexp
+	/*
+	 * In this rule, want_regexp tells yylex that the next thing
+	 * is a regexp so it should read up to the closing slash.
+	 */
+	: '/'
+		{ ++want_regexp; }
+	  REGEXP '/'
+		{
+		  NODE *n;
+		  int len;
+
+		  getnode(n);
+		  n->type = Node_regex;
+		  len = strlen($3);
+		  n->re_exp = make_string($3, len);
+		  n->re_reg = make_regexp($3, len, 0, 1);
+		  n->re_text = NULL;
+		  n->re_flags = CONST;
+		  n->re_cnt = 1;
+		  $$ = n;
+		}
+	;
+
+action
+	: l_brace statements r_brace opt_semi opt_nls
+		{ $$ = $2 ; }
+	| l_brace r_brace opt_semi opt_nls
+		{ $$ = NULL; }
+	;
+
+statements
+	: statement
+		{ $$ = $1; }
+	| statements statement
+		{
+			if ($1 == NULL || $1->type != Node_statement_list)
+				$1 = node($1, Node_statement_list,(NODE *)NULL);
+	    		$$ = append_right($1,
+				node( $2, Node_statement_list, (NODE *)NULL));
+	    		yyerrok;
+		}
+	| error
+		{ $$ = NULL; }
+	| statements error
+		{ $$ = NULL; }
+	;
+
+statement_term
+	: nls
+	| semi opt_nls
+	;
+
+statement
+	: semi opt_nls
+		{ $$ = NULL; }
+	| l_brace r_brace
+		{ $$ = NULL; }
+	| l_brace statements r_brace
+		{ $$ = $2; }
+	| if_statement
+		{ $$ = $1; }
+	| LEX_WHILE '(' exp r_paren opt_nls statement
+		{ $$ = node ($3, Node_K_while, $6); }
+	| LEX_DO opt_nls statement LEX_WHILE '(' exp r_paren opt_nls
+		{ $$ = node ($6, Node_K_do, $3); }
+	| LEX_FOR '(' NAME LEX_IN NAME r_paren opt_nls statement
+	  {
+		$$ = node ($8, Node_K_arrayfor, make_for_loop(variable($3,1),
+			(NODE *)NULL, variable($5,1)));
+	  }
+	| LEX_FOR '(' opt_exp semi exp semi opt_exp r_paren opt_nls statement
+	  {
+		$$ = node($10, Node_K_for, (NODE *)make_for_loop($3, $5, $7));
+	  }
+	| LEX_FOR '(' opt_exp semi semi opt_exp r_paren opt_nls statement
+	  {
+		$$ = node ($9, Node_K_for,
+			(NODE *)make_for_loop($3, (NODE *)NULL, $6));
+	  }
+	| LEX_BREAK statement_term
+	   /* for break, maybe we'll have to remember where to break to */
+		{ $$ = node ((NODE *)NULL, Node_K_break, (NODE *)NULL); }
+	| LEX_CONTINUE statement_term
+	   /* similarly */
+		{ $$ = node ((NODE *)NULL, Node_K_continue, (NODE *)NULL); }
+	| print '(' expression_list r_paren output_redir statement_term
+		{ $$ = node ($3, $1, $5); }
+	| print opt_rexpression_list output_redir statement_term
+		{
+			if ($1 == Node_K_print && $2 == NULL)
+				$2 = node(node(make_number(0.0),
+					       Node_field_spec,
+					       (NODE *) NULL),
+					  Node_expression_list,
+					  (NODE *) NULL);
+
+			$$ = node ($2, $1, $3);
+		}
+	| LEX_NEXT opt_exp statement_term
+		{ NODETYPE type;
+
+		  if ($2 && $2 == lookup("file")) {
+			if (do_lint)
+				warning("`next file' is a gawk extension");
+			else if (do_unix || do_posix)
+				yyerror("`next file' is a gawk extension");
+			 else if (! io_allowed)
+				yyerror("`next file' used in BEGIN or END action");
+			type = Node_K_nextfile;
+		  } else {
+			if (! io_allowed)
+				yyerror("next used in BEGIN or END action");
+			type = Node_K_next;
+		}
+		  $$ = node ((NODE *)NULL, type, (NODE *)NULL);
+		}
+	| LEX_EXIT opt_exp statement_term
+		{ $$ = node ($2, Node_K_exit, (NODE *)NULL); }
+	| LEX_RETURN
+		{ if (! can_return) yyerror("return used outside function context"); }
+	  opt_exp statement_term
+		{ $$ = node ($3, Node_K_return, (NODE *)NULL); }
+	| LEX_DELETE NAME '[' expression_list ']' statement_term
+		{ $$ = node (variable($2,1), Node_K_delete, $4); }
+	| exp statement_term
+		{ $$ = $1; }
+	;
+
+print
+	: LEX_PRINT
+		{ $$ = $1; }
+	| LEX_PRINTF
+		{ $$ = $1; }
+	;
+
+if_statement
+	: LEX_IF '(' exp r_paren opt_nls statement
+	  {
+		$$ = node($3, Node_K_if, 
+			node($6, Node_if_branches, (NODE *)NULL));
+	  }
+	| LEX_IF '(' exp r_paren opt_nls statement
+	     LEX_ELSE opt_nls statement
+		{ $$ = node ($3, Node_K_if,
+				node ($6, Node_if_branches, $9)); }
+	;
+
+nls
+	: NEWLINE
+		{ want_assign = 0; }
+	| nls NEWLINE
+	;
+
+opt_nls
+	: /* empty */
+	| nls
+	;
+
+input_redir
+	: /* empty */
+		{ $$ = NULL; }
+	| '<' simp_exp
+		{ $$ = node ($2, Node_redirect_input, (NODE *)NULL); }
+	;
+
+output_redir
+	: /* empty */
+		{ $$ = NULL; }
+	| '>' exp
+		{ $$ = node ($2, Node_redirect_output, (NODE *)NULL); }
+	| APPEND_OP exp
+		{ $$ = node ($2, Node_redirect_append, (NODE *)NULL); }
+	| '|' exp
+		{ $$ = node ($2, Node_redirect_pipe, (NODE *)NULL); }
+	;
+
+opt_param_list
+	: /* empty */
+		{ $$ = NULL; }
+	| param_list
+		{ $$ = $1; }
+	;
+
+param_list
+	: NAME
+		{ $$ = make_param($1); }
+	| param_list comma NAME
+		{ $$ = append_right($1, make_param($3)); yyerrok; }
+	| error
+		{ $$ = NULL; }
+	| param_list error
+		{ $$ = NULL; }
+	| param_list comma error
+		{ $$ = NULL; }
+	;
+
+/* optional expression, as in for loop */
+opt_exp
+	: /* empty */
+		{ $$ = NULL; }
+	| exp
+		{ $$ = $1; }
+	;
+
+opt_rexpression_list
+	: /* empty */
+		{ $$ = NULL; }
+	| rexpression_list
+		{ $$ = $1; }
+	;
+
+rexpression_list
+	: rexp
+		{ $$ = node ($1, Node_expression_list, (NODE *)NULL); }
+	| rexpression_list comma rexp
+	  {
+		$$ = append_right($1,
+			node( $3, Node_expression_list, (NODE *)NULL));
+		yyerrok;
+	  }
+	| error
+		{ $$ = NULL; }
+	| rexpression_list error
+		{ $$ = NULL; }
+	| rexpression_list error rexp
+		{ $$ = NULL; }
+	| rexpression_list comma error
+		{ $$ = NULL; }
+	;
+
+opt_expression_list
+	: /* empty */
+		{ $$ = NULL; }
+	| expression_list
+		{ $$ = $1; }
+	;
+
+expression_list
+	: exp
+		{ $$ = node ($1, Node_expression_list, (NODE *)NULL); }
+	| expression_list comma exp
+		{
+			$$ = append_right($1,
+				node( $3, Node_expression_list, (NODE *)NULL));
+			yyerrok;
+		}
+	| error
+		{ $$ = NULL; }
+	| expression_list error
+		{ $$ = NULL; }
+	| expression_list error exp
+		{ $$ = NULL; }
+	| expression_list comma error
+		{ $$ = NULL; }
+	;
+
+/* Expressions, not including the comma operator.  */
+exp	: variable ASSIGNOP 
+		{ want_assign = 0; }
+	  exp
+		{
+		  if (do_lint && $4->type == Node_regex)
+			warning("Regular expression on left of assignment.");
+		  $$ = node ($1, $2, $4);
+		}
+	| '(' expression_list r_paren LEX_IN NAME
+		{ $$ = node (variable($5,1), Node_in_array, $2); }
+	| exp '|' LEX_GETLINE opt_variable
+		{
+		  $$ = node ($4, Node_K_getline,
+			 node ($1, Node_redirect_pipein, (NODE *)NULL));
+		}
+	| LEX_GETLINE opt_variable input_redir
+		{
+		  if (do_lint && ! io_allowed && $3 == NULL)
+			warning("non-redirected getline undefined inside BEGIN or END action");
+		  $$ = node ($2, Node_K_getline, $3);
+		}
+	| exp LEX_AND exp
+		{ $$ = node ($1, Node_and, $3); }
+	| exp LEX_OR exp
+		{ $$ = node ($1, Node_or, $3); }
+	| exp MATCHOP exp
+		{
+		  if ($1->type == Node_regex)
+			warning("Regular expression on left of MATCH operator.");
+		  $$ = node ($1, $2, mk_rexp($3));
+		}
+	| regexp
+		{ $$ = $1; }
+	| '!' regexp %prec UNARY
+		{
+		  $$ = node(node(make_number(0.0),
+				 Node_field_spec,
+				 (NODE *) NULL),
+		            Node_nomatch,
+			    $2);
+		}
+	| exp LEX_IN NAME
+		{ $$ = node (variable($3,1), Node_in_array, $1); }
+	| exp RELOP exp
+		{
+		  if (do_lint && $3->type == Node_regex)
+			warning("Regular expression on left of comparison.");
+		  $$ = node ($1, $2, $3);
+		}
+	| exp '<' exp
+		{ $$ = node ($1, Node_less, $3); }
+	| exp '>' exp
+		{ $$ = node ($1, Node_greater, $3); }
+	| exp '?' exp ':' exp
+		{ $$ = node($1, Node_cond_exp, node($3, Node_if_branches, $5));}
+	| simp_exp
+		{ $$ = $1; }
+	| exp simp_exp %prec CONCAT_OP
+		{ $$ = node ($1, Node_concat, $2); }
+	;
+
+rexp	
+	: variable ASSIGNOP 
+		{ want_assign = 0; }
+	  rexp
+		{ $$ = node ($1, $2, $4); }
+	| rexp LEX_AND rexp
+		{ $$ = node ($1, Node_and, $3); }
+	| rexp LEX_OR rexp
+		{ $$ = node ($1, Node_or, $3); }
+	| LEX_GETLINE opt_variable input_redir
+		{
+		  if (do_lint && ! io_allowed && $3 == NULL)
+			warning("non-redirected getline undefined inside BEGIN or END action");
+		  $$ = node ($2, Node_K_getline, $3);
+		}
+	| regexp
+		{ $$ = $1; } 
+	| '!' regexp %prec UNARY
+		{ $$ = node((NODE *) NULL, Node_nomatch, $2); }
+	| rexp MATCHOP rexp
+		 { $$ = node ($1, $2, mk_rexp($3)); }
+	| rexp LEX_IN NAME
+		{ $$ = node (variable($3,1), Node_in_array, $1); }
+	| rexp RELOP rexp
+		{ $$ = node ($1, $2, $3); }
+	| rexp '?' rexp ':' rexp
+		{ $$ = node($1, Node_cond_exp, node($3, Node_if_branches, $5));}
+	| simp_exp
+		{ $$ = $1; }
+	| rexp simp_exp %prec CONCAT_OP
+		{ $$ = node ($1, Node_concat, $2); }
+	;
+
+simp_exp
+	: non_post_simp_exp
+	/* Binary operators in order of decreasing precedence.  */
+	| simp_exp '^' simp_exp
+		{ $$ = node ($1, Node_exp, $3); }
+	| simp_exp '*' simp_exp
+		{ $$ = node ($1, Node_times, $3); }
+	| simp_exp '/' simp_exp
+		{ $$ = node ($1, Node_quotient, $3); }
+	| simp_exp '%' simp_exp
+		{ $$ = node ($1, Node_mod, $3); }
+	| simp_exp '+' simp_exp
+		{ $$ = node ($1, Node_plus, $3); }
+	| simp_exp '-' simp_exp
+		{ $$ = node ($1, Node_minus, $3); }
+	| variable INCREMENT
+		{ $$ = node ($1, Node_postincrement, (NODE *)NULL); }
+	| variable DECREMENT
+		{ $$ = node ($1, Node_postdecrement, (NODE *)NULL); }
+	;
+
+non_post_simp_exp
+	: '!' simp_exp %prec UNARY
+		{ $$ = node ($2, Node_not,(NODE *) NULL); }
+	| '(' exp r_paren
+		{ $$ = $2; }
+	| LEX_BUILTIN
+	  '(' opt_expression_list r_paren
+		{ $$ = snode ($3, Node_builtin, (int) $1); }
+	| LEX_LENGTH '(' opt_expression_list r_paren
+		{ $$ = snode ($3, Node_builtin, (int) $1); }
+	| LEX_LENGTH
+	  {
+		if (do_lint)
+			warning("call of `length' without parentheses is not portable");
+		$$ = snode ((NODE *)NULL, Node_builtin, (int) $1);
+		if (do_posix)
+			warning( "call of `length' without parentheses is deprecated by POSIX");
+	  }
+	| FUNC_CALL '(' opt_expression_list r_paren
+	  {
+		$$ = node ($3, Node_func_call, make_string($1, strlen($1)));
+	  }
+	| variable
+	| INCREMENT variable
+		{ $$ = node ($2, Node_preincrement, (NODE *)NULL); }
+	| DECREMENT variable
+		{ $$ = node ($2, Node_predecrement, (NODE *)NULL); }
+	| YNUMBER
+		{ $$ = $1; }
+	| YSTRING
+		{ $$ = $1; }
+
+	| '-' simp_exp    %prec UNARY
+		{ if ($2->type == Node_val) {
+			$2->numbr = -(force_number($2));
+			$$ = $2;
+		  } else
+			$$ = node ($2, Node_unary_minus, (NODE *)NULL);
+		}
+	| '+' simp_exp    %prec UNARY
+		{ $$ = $2; }
+	;
+
+opt_variable
+	: /* empty */
+		{ $$ = NULL; }
+	| variable
+		{ $$ = $1; }
+	;
+
+variable
+	: NAME
+		{ $$ = variable($1,1); }
+	| NAME '[' expression_list ']'
+		{
+		if ($3->rnode == NULL) {
+			$$ = node (variable($1,1), Node_subscript, $3->lnode);
+			freenode($3);
+		} else
+			$$ = node (variable($1,1), Node_subscript, $3);
+		}
+	| '$' non_post_simp_exp
+		{ $$ = node ($2, Node_field_spec, (NODE *)NULL); }
+	;
+
+l_brace
+	: '{' opt_nls
+	;
+
+r_brace
+	: '}' opt_nls	{ yyerrok; }
+	;
+
+r_paren
+	: ')' { yyerrok; }
+	;
+
+opt_semi
+	: /* empty */
+	| semi
+	;
+
+semi
+	: ';'	{ yyerrok; want_assign = 0; }
+	;
+
+comma	: ',' opt_nls	{ yyerrok; }
+	;
+
+%%
+
+struct token {
+	char *operator;		/* text to match */
+	NODETYPE value;		/* node type */
+	int class;		/* lexical class */
+	unsigned flags;		/* # of args. allowed and compatability */
+#	define	ARGS	0xFF	/* 0, 1, 2, 3 args allowed (any combination */
+#	define	A(n)	(1<<(n))
+#	define	VERSION	0xFF00	/* old awk is zero */
+#	define	NOT_OLD		0x0100	/* feature not in old awk */
+#	define	NOT_POSIX	0x0200	/* feature not in POSIX */
+#	define	GAWKX		0x0400	/* gawk extension */
+	NODE *(*ptr) ();	/* function that implements this keyword */
+};
+
+extern NODE
+	*do_exp(),	*do_getline(),	*do_index(),	*do_length(),
+	*do_sqrt(),	*do_log(),	*do_sprintf(),	*do_substr(),
+	*do_split(),	*do_system(),	*do_int(),	*do_close(),
+	*do_atan2(),	*do_sin(),	*do_cos(),	*do_rand(),
+	*do_srand(),	*do_match(),	*do_tolower(),	*do_toupper(),
+	*do_sub(),	*do_gsub(),	*do_strftime(),	*do_systime();
+
+/* Tokentab is sorted ascii ascending order, so it can be binary searched. */
+
+static struct token tokentab[] = {
+{"BEGIN",	Node_illegal,	 LEX_BEGIN,	0,		0},
+{"END",		Node_illegal,	 LEX_END,	0,		0},
+{"atan2",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(2),	do_atan2},
+{"break",	Node_K_break,	 LEX_BREAK,	0,		0},
+{"close",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(1),	do_close},
+{"continue",	Node_K_continue, LEX_CONTINUE,	0,		0},
+{"cos",		Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(1),	do_cos},
+{"delete",	Node_K_delete,	 LEX_DELETE,	NOT_OLD,	0},
+{"do",		Node_K_do,	 LEX_DO,	NOT_OLD,	0},
+{"else",	Node_illegal,	 LEX_ELSE,	0,		0},
+{"exit",	Node_K_exit,	 LEX_EXIT,	0,		0},
+{"exp",		Node_builtin,	 LEX_BUILTIN,	A(1),		do_exp},
+{"for",		Node_K_for,	 LEX_FOR,	0,		0},
+{"func",	Node_K_function, LEX_FUNCTION,	NOT_POSIX|NOT_OLD,	0},
+{"function",	Node_K_function, LEX_FUNCTION,	NOT_OLD,	0},
+{"getline",	Node_K_getline,	 LEX_GETLINE,	NOT_OLD,	0},
+{"gsub",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(2)|A(3), do_gsub},
+{"if",		Node_K_if,	 LEX_IF,	0,		0},
+{"in",		Node_illegal,	 LEX_IN,	0,		0},
+{"index",	Node_builtin,	 LEX_BUILTIN,	A(2),		do_index},
+{"int",		Node_builtin,	 LEX_BUILTIN,	A(1),		do_int},
+{"length",	Node_builtin,	 LEX_LENGTH,	A(0)|A(1),	do_length},
+{"log",		Node_builtin,	 LEX_BUILTIN,	A(1),		do_log},
+{"match",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(2),	do_match},
+{"next",	Node_K_next,	 LEX_NEXT,	0,		0},
+{"print",	Node_K_print,	 LEX_PRINT,	0,		0},
+{"printf",	Node_K_printf,	 LEX_PRINTF,	0,		0},
+{"rand",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(0),	do_rand},
+{"return",	Node_K_return,	 LEX_RETURN,	NOT_OLD,	0},
+{"sin",		Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(1),	do_sin},
+{"split",	Node_builtin,	 LEX_BUILTIN,	A(2)|A(3),	do_split},
+{"sprintf",	Node_builtin,	 LEX_BUILTIN,	0,		do_sprintf},
+{"sqrt",	Node_builtin,	 LEX_BUILTIN,	A(1),		do_sqrt},
+{"srand",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(0)|A(1), do_srand},
+{"strftime",	Node_builtin,	 LEX_BUILTIN,	GAWKX|A(1)|A(2), do_strftime},
+{"sub",		Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(2)|A(3), do_sub},
+{"substr",	Node_builtin,	 LEX_BUILTIN,	A(2)|A(3),	do_substr},
+{"system",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(1),	do_system},
+{"systime",	Node_builtin,	 LEX_BUILTIN,	GAWKX|A(0),	do_systime},
+{"tolower",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(1),	do_tolower},
+{"toupper",	Node_builtin,	 LEX_BUILTIN,	NOT_OLD|A(1),	do_toupper},
+{"while",	Node_K_while,	 LEX_WHILE,	0,		0},
+};
+
+/* VARARGS0 */
+static void
+yyerror(va_alist)
+va_dcl
+{
+	va_list args;
+	char *mesg = NULL;
+	register char *bp, *cp;
+	char *scan;
+	char buf[120];
+
+	errcount++;
+	/* Find the current line in the input file */
+	if (lexptr) {
+		if (!thisline) {
+			cp = lexeme;
+			if (*cp == '\n') {
+				cp--;
+				mesg = "unexpected newline";
+			}
+			for ( ; cp != lexptr_begin && *cp != '\n'; --cp)
+				;
+			if (*cp == '\n')
+				cp++;
+			thisline = cp;
+		}
+		/* NL isn't guaranteed */
+		bp = lexeme;
+		while (bp < lexend && *bp && *bp != '\n')
+			bp++;
+	} else {
+		thisline = "(END OF FILE)";
+		bp = thisline + 13;
+	}
+	msg("%.*s", (int) (bp - thisline), thisline);
+	bp = buf;
+	cp = buf + sizeof(buf) - 24;	/* 24 more than longest msg. input */
+	if (lexptr) {
+		scan = thisline;
+		while (bp < cp && scan < lexeme)
+			if (*scan++ == '\t')
+				*bp++ = '\t';
+			else
+				*bp++ = ' ';
+		*bp++ = '^';
+		*bp++ = ' ';
+	}
+	va_start(args);
+	if (mesg == NULL)
+		mesg = va_arg(args, char *);
+	strcpy(bp, mesg);
+	err("", buf, args);
+	va_end(args);
+	exit(2);
+}
+
+static char *
+get_src_buf()
+{
+	static int samefile = 0;
+	static int nextfile = 0;
+	static char *buf = NULL;
+	static int fd;
+	int n;
+	register char *scan;
+	static int len = 0;
+	static int did_newline = 0;
+#	define	SLOP	128	/* enough space to hold most source lines */
+
+	if (nextfile > numfiles)
+		return NULL;
+
+	if (srcfiles[nextfile].stype == CMDLINE) {
+		if (len == 0) {
+			len = strlen(srcfiles[nextfile].val);
+			sourceline = 1;
+			lexptr = lexptr_begin = srcfiles[nextfile].val;
+			lexend = lexptr + len;
+		} else if (!did_newline && *(lexptr-1) != '\n') {
+			/*
+			 * The following goop is to ensure that the source
+			 * ends with a newline and that the entire current
+			 * line is available for error messages.
+			 */
+			int offset;
+
+			did_newline = 1;
+			offset = lexptr - lexeme;
+			for (scan = lexeme; scan > lexptr_begin; scan--)
+				if (*scan == '\n') {
+					scan++;
+					break;
+				}
+			len = lexptr - scan;
+			emalloc(buf, char *, len+1, "get_src_buf");
+			memcpy(buf, scan, len);
+			thisline = buf;
+			lexptr = buf + len;
+			*lexptr = '\n';
+			lexeme = lexptr - offset;
+			lexptr_begin = buf;
+			lexend = lexptr + 1;
+		} else {
+			len = 0;
+			lexeme = lexptr = lexptr_begin = NULL;
+		}
+		if (lexptr == NULL && ++nextfile <= numfiles)
+			return get_src_buf();
+		return lexptr;
+	}
+	if (!samefile) {
+		source = srcfiles[nextfile].val;
+		if (source == NULL) {
+			if (buf) {
+				free(buf);
+				buf = NULL;
+			}
+			len = 0;
+			return lexeme = lexptr = lexptr_begin = NULL;
+		}
+		fd = pathopen(source);
+		if (fd == -1)
+			fatal("can't open source file \"%s\" for reading (%s)",
+				source, strerror(errno));
+		len = optimal_bufsize(fd);
+		if (buf)
+			free(buf);
+		emalloc(buf, char *, len + SLOP, "get_src_buf");
+		lexptr_begin = buf + SLOP;
+		samefile = 1;
+		sourceline = 1;
+	} else {
+		/*
+		 * Here, we retain the current source line (up to length SLOP)
+		 * in the beginning of the buffer that was overallocated above
+		 */
+		int offset;
+		int linelen;
+
+		offset = lexptr - lexeme;
+		for (scan = lexeme; scan > lexptr_begin; scan--)
+			if (*scan == '\n') {
+				scan++;
+				break;
+			}
+		linelen = lexptr - scan;
+		if (linelen > SLOP)
+			linelen = SLOP;
+		thisline = buf + SLOP - linelen;
+		memcpy(thisline, scan, linelen);
+		lexeme = buf + SLOP - offset;
+		lexptr_begin = thisline;
+	}
+	n = read(fd, buf + SLOP, len);
+	if (n == -1)
+		fatal("can't read sourcefile \"%s\" (%s)",
+			source, strerror(errno));
+	if (n == 0) {
+		samefile = 0;
+		nextfile++;
+		len = 0;
+		return get_src_buf();
+	}
+	lexptr = buf + SLOP;
+	lexend = lexptr + n;
+	return buf;
+}
+
+#define	tokadd(x) (*token++ = (x), token == tokend ? tokexpand() : token)
+
+char *
+tokexpand()
+{
+	static int toksize = 60;
+	int tokoffset;
+
+	tokoffset = token - tokstart;
+	toksize *= 2;
+	if (tokstart)
+		erealloc(tokstart, char *, toksize, "tokexpand");
+	else
+		emalloc(tokstart, char *, toksize, "tokexpand");
+	tokend = tokstart + toksize;
+	token = tokstart + tokoffset;
+	return token;
+}
+
+#if DEBUG
+char
+nextc() {
+	if (lexptr && lexptr < lexend)
+		return *lexptr++;
+	else if (get_src_buf())
+		return *lexptr++;
+	else
+		return '\0';
+}
+#else
+#define	nextc()	((lexptr && lexptr < lexend) ? \
+			*lexptr++ : \
+			(get_src_buf() ? *lexptr++ : '\0') \
+		)
+#endif
+#define pushback() (lexptr && lexptr > lexptr_begin ? lexptr-- : lexptr)
+
+/*
+ * Read the input and turn it into tokens.
+ */
+
+static int
+yylex()
+{
+	register int c;
+	int seen_e = 0;		/* These are for numbers */
+	int seen_point = 0;
+	int esc_seen;		/* for literal strings */
+	int low, mid, high;
+	static int did_newline = 0;
+	char *tokkey;
+
+	if (!nextc())
+		return 0;
+	pushback();
+	lexeme = lexptr;
+	thisline = NULL;
+	if (want_regexp) {
+		int in_brack = 0;
+
+		want_regexp = 0;
+		token = tokstart;
+		while ((c = nextc()) != 0) {
+			switch (c) {
+			case '[':
+				in_brack = 1;
+				break;
+			case ']':
+				in_brack = 0;
+				break;
+			case '\\':
+				if ((c = nextc()) == '\0') {
+					yyerror("unterminated regexp ends with \\ at end of file");
+				} else if (c == '\n') {
+					sourceline++;
+					continue;
+				} else
+					tokadd('\\');
+				break;
+			case '/':	/* end of the regexp */
+				if (in_brack)
+					break;
+
+				pushback();
+				tokadd('\0');
+				yylval.sval = tokstart;
+				return REGEXP;
+			case '\n':
+				pushback();
+				yyerror("unterminated regexp");
+			case '\0':
+				yyerror("unterminated regexp at end of file");
+			}
+			tokadd(c);
+		}
+	}
+retry:
+	while ((c = nextc()) == ' ' || c == '\t')
+		;
+
+	lexeme = lexptr ? lexptr - 1 : lexptr;
+	thisline = NULL;
+	token = tokstart;
+	yylval.nodetypeval = Node_illegal;
+
+	switch (c) {
+	case 0:
+		return 0;
+
+	case '\n':
+		sourceline++;
+		return NEWLINE;
+
+	case '#':		/* it's a comment */
+		while ((c = nextc()) != '\n') {
+			if (c == '\0')
+				return 0;
+		}
+		sourceline++;
+		return NEWLINE;
+
+	case '\\':
+#ifdef RELAXED_CONTINUATION
+		if (!do_unix) {	/* strip trailing white-space and/or comment */
+			while ((c = nextc()) == ' ' || c == '\t') continue;
+			if (c == '#')
+				while ((c = nextc()) != '\n') if (!c) break;
+			pushback();
+		}
+#endif /*RELAXED_CONTINUATION*/
+		if (nextc() == '\n') {
+			sourceline++;
+			goto retry;
+		} else
+			yyerror("inappropriate use of backslash");
+		break;
+
+	case '$':
+		want_assign = 1;
+		return '$';
+
+	case ')':
+	case ']':
+	case '(':	
+	case '[':
+	case ';':
+	case ':':
+	case '?':
+	case '{':
+	case ',':
+		return c;
+
+	case '*':
+		if ((c = nextc()) == '=') {
+			yylval.nodetypeval = Node_assign_times;
+			return ASSIGNOP;
+		} else if (do_posix) {
+			pushback();
+			return '*';
+		} else if (c == '*') {
+			/* make ** and **= aliases for ^ and ^= */
+			static int did_warn_op = 0, did_warn_assgn = 0;
+
+			if (nextc() == '=') {
+				if (do_lint && ! did_warn_assgn) {
+					did_warn_assgn = 1;
+					warning("**= is not allowed by POSIX");
+				}
+				yylval.nodetypeval = Node_assign_exp;
+				return ASSIGNOP;
+			} else {
+				pushback();
+				if (do_lint && ! did_warn_op) {
+					did_warn_op = 1;
+					warning("** is not allowed by POSIX");
+				}
+				return '^';
+			}
+		}
+		pushback();
+		return '*';
+
+	case '/':
+		if (want_assign) {
+			if (nextc() == '=') {
+				yylval.nodetypeval = Node_assign_quotient;
+				return ASSIGNOP;
+			}
+			pushback();
+		}
+		return '/';
+
+	case '%':
+		if (nextc() == '=') {
+			yylval.nodetypeval = Node_assign_mod;
+			return ASSIGNOP;
+		}
+		pushback();
+		return '%';
+
+	case '^':
+	{
+		static int did_warn_op = 0, did_warn_assgn = 0;
+
+		if (nextc() == '=') {
+
+			if (do_lint && ! did_warn_assgn) {
+				did_warn_assgn = 1;
+				warning("operator `^=' is not supported in old awk");
+			}
+			yylval.nodetypeval = Node_assign_exp;
+			return ASSIGNOP;
+		}
+		pushback();
+		if (do_lint && ! did_warn_op) {
+			did_warn_op = 1;
+			warning("operator `^' is not supported in old awk");
+		}
+		return '^';
+	}
+
+	case '+':
+		if ((c = nextc()) == '=') {
+			yylval.nodetypeval = Node_assign_plus;
+			return ASSIGNOP;
+		}
+		if (c == '+')
+			return INCREMENT;
+		pushback();
+		return '+';
+
+	case '!':
+		if ((c = nextc()) == '=') {
+			yylval.nodetypeval = Node_notequal;
+			return RELOP;
+		}
+		if (c == '~') {
+			yylval.nodetypeval = Node_nomatch;
+			want_assign = 0;
+			return MATCHOP;
+		}
+		pushback();
+		return '!';
+
+	case '<':
+		if (nextc() == '=') {
+			yylval.nodetypeval = Node_leq;
+			return RELOP;
+		}
+		yylval.nodetypeval = Node_less;
+		pushback();
+		return '<';
+
+	case '=':
+		if (nextc() == '=') {
+			yylval.nodetypeval = Node_equal;
+			return RELOP;
+		}
+		yylval.nodetypeval = Node_assign;
+		pushback();
+		return ASSIGNOP;
+
+	case '>':
+		if ((c = nextc()) == '=') {
+			yylval.nodetypeval = Node_geq;
+			return RELOP;
+		} else if (c == '>') {
+			yylval.nodetypeval = Node_redirect_append;
+			return APPEND_OP;
+		}
+		yylval.nodetypeval = Node_greater;
+		pushback();
+		return '>';
+
+	case '~':
+		yylval.nodetypeval = Node_match;
+		want_assign = 0;
+		return MATCHOP;
+
+	case '}':
+		/*
+		 * Added did newline stuff.  Easier than
+		 * hacking the grammar
+		 */
+		if (did_newline) {
+			did_newline = 0;
+			return c;
+		}
+		did_newline++;
+		--lexptr;	/* pick up } next time */
+		return NEWLINE;
+
+	case '"':
+		esc_seen = 0;
+		while ((c = nextc()) != '"') {
+			if (c == '\n') {
+				pushback();
+				yyerror("unterminated string");
+			}
+			if (c == '\\') {
+				c = nextc();
+				if (c == '\n') {
+					sourceline++;
+					continue;
+				}
+				esc_seen = 1;
+				tokadd('\\');
+			}
+			if (c == '\0') {
+				pushback();
+				yyerror("unterminated string");
+			}
+			tokadd(c);
+		}
+		yylval.nodeval = make_str_node(tokstart,
+					token - tokstart, esc_seen ? SCAN : 0);
+		yylval.nodeval->flags |= PERM;
+		return YSTRING;
+
+	case '-':
+		if ((c = nextc()) == '=') {
+			yylval.nodetypeval = Node_assign_minus;
+			return ASSIGNOP;
+		}
+		if (c == '-')
+			return DECREMENT;
+		pushback();
+		return '-';
+
+	case '.':
+		c = nextc();
+		pushback();
+		if (!isdigit(c))
+			return '.';
+		else
+			c = '.';	/* FALL THROUGH */
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+		/* It's a number */
+		for (;;) {
+			int gotnumber = 0;
+
+			tokadd(c);
+			switch (c) {
+			case '.':
+				if (seen_point) {
+					gotnumber++;
+					break;
+				}
+				++seen_point;
+				break;
+			case 'e':
+			case 'E':
+				if (seen_e) {
+					gotnumber++;
+					break;
+				}
+				++seen_e;
+				if ((c = nextc()) == '-' || c == '+')
+					tokadd(c);
+				else
+					pushback();
+				break;
+			case '0':
+			case '1':
+			case '2':
+			case '3':
+			case '4':
+			case '5':
+			case '6':
+			case '7':
+			case '8':
+			case '9':
+				break;
+			default:
+				gotnumber++;
+			}
+			if (gotnumber)
+				break;
+			c = nextc();
+		}
+		pushback();
+		yylval.nodeval = make_number(atof(tokstart));
+		yylval.nodeval->flags |= PERM;
+		return YNUMBER;
+
+	case '&':
+		if ((c = nextc()) == '&') {
+			yylval.nodetypeval = Node_and;
+			for (;;) {
+				c = nextc();
+				if (c == '\0')
+					break;
+				if (c == '#') {
+					while ((c = nextc()) != '\n' && c != '\0')
+						;
+					if (c == '\0')
+						break;
+				}
+				if (c == '\n')
+					sourceline++;
+				if (! isspace(c)) {
+					pushback();
+					break;
+				}
+			}
+			want_assign = 0;
+			return LEX_AND;
+		}
+		pushback();
+		return '&';
+
+	case '|':
+		if ((c = nextc()) == '|') {
+			yylval.nodetypeval = Node_or;
+			for (;;) {
+				c = nextc();
+				if (c == '\0')
+					break;
+				if (c == '#') {
+					while ((c = nextc()) != '\n' && c != '\0')
+						;
+					if (c == '\0')
+						break;
+				}
+				if (c == '\n')
+					sourceline++;
+				if (! isspace(c)) {
+					pushback();
+					break;
+				}
+			}
+			want_assign = 0;
+			return LEX_OR;
+		}
+		pushback();
+		return '|';
+	}
+
+	if (c != '_' && ! isalpha(c))
+		yyerror("Invalid char '%c' in expression\n", c);
+
+	/* it's some type of name-type-thing.  Find its length */
+	token = tokstart;
+	while (is_identchar(c)) {
+		tokadd(c);
+		c = nextc();
+	}
+	tokadd('\0');
+	emalloc(tokkey, char *, token - tokstart, "yylex");
+	memcpy(tokkey, tokstart, token - tokstart);
+	pushback();
+
+	/* See if it is a special token.  */
+	low = 0;
+	high = (sizeof (tokentab) / sizeof (tokentab[0])) - 1;
+	while (low <= high) {
+		int i/* , c */;
+
+		mid = (low + high) / 2;
+		c = *tokstart - tokentab[mid].operator[0];
+		i = c ? c : strcmp (tokstart, tokentab[mid].operator);
+
+		if (i < 0) {		/* token < mid */
+			high = mid - 1;
+		} else if (i > 0) {	/* token > mid */
+			low = mid + 1;
+		} else {
+			if (do_lint) {
+				if (tokentab[mid].flags & GAWKX)
+					warning("%s() is a gawk extension",
+						tokentab[mid].operator);
+				if (tokentab[mid].flags & NOT_POSIX)
+					warning("POSIX does not allow %s",
+						tokentab[mid].operator);
+				if (tokentab[mid].flags & NOT_OLD)
+					warning("%s is not supported in old awk",
+						tokentab[mid].operator);
+			}
+			if ((do_unix && (tokentab[mid].flags & GAWKX))
+			    || (do_posix && (tokentab[mid].flags & NOT_POSIX)))
+				break;
+			if (tokentab[mid].class == LEX_BUILTIN
+			    || tokentab[mid].class == LEX_LENGTH
+			   )
+				yylval.lval = mid;
+			else
+				yylval.nodetypeval = tokentab[mid].value;
+
+			return tokentab[mid].class;
+		}
+	}
+
+	yylval.sval = tokkey;
+	if (*lexptr == '(')
+		return FUNC_CALL;
+	else {
+		want_assign = 1;
+		return NAME;
+	}
+}
+
+static NODE *
+node_common(op)
+NODETYPE op;
+{
+	register NODE *r;
+
+	getnode(r);
+	r->type = op;
+	r->flags = MALLOC;
+	/* if lookahead is NL, lineno is 1 too high */
+	if (lexeme && *lexeme == '\n')
+		r->source_line = sourceline - 1;
+	else
+		r->source_line = sourceline;
+	r->source_file = source;
+	return r;
+}
+
+/*
+ * This allocates a node with defined lnode and rnode. 
+ */
+NODE *
+node(left, op, right)
+NODE *left, *right;
+NODETYPE op;
+{
+	register NODE *r;
+
+	r = node_common(op);
+	r->lnode = left;
+	r->rnode = right;
+	return r;
+}
+
+/*
+ * This allocates a node with defined subnode and proc for builtin functions
+ * Checks for arg. count and supplies defaults where possible.
+ */
+static NODE *
+snode(subn, op, idx)
+NODETYPE op;
+int idx;
+NODE *subn;
+{
+	register NODE *r;
+	register NODE *n;
+	int nexp = 0;
+	int args_allowed;
+
+	r = node_common(op);
+
+	/* traverse expression list to see how many args. given */
+	for (n= subn; n; n= n->rnode) {
+		nexp++;
+		if (nexp > 3)
+			break;
+	}
+
+	/* check against how many args. are allowed for this builtin */
+	args_allowed = tokentab[idx].flags & ARGS;
+	if (args_allowed && !(args_allowed & A(nexp)))
+		fatal("%s() cannot have %d argument%c",
+			tokentab[idx].operator, nexp, nexp == 1 ? ' ' : 's');
+
+	r->proc = tokentab[idx].ptr;
+
+	/* special case processing for a few builtins */
+	if (nexp == 0 && r->proc == do_length) {
+		subn = node(node(make_number(0.0),Node_field_spec,(NODE *)NULL),
+		            Node_expression_list,
+			    (NODE *) NULL);
+	} else if (r->proc == do_match) {
+		if (subn->rnode->lnode->type != Node_regex)
+			subn->rnode->lnode = mk_rexp(subn->rnode->lnode);
+	} else if (r->proc == do_sub || r->proc == do_gsub) {
+		if (subn->lnode->type != Node_regex)
+			subn->lnode = mk_rexp(subn->lnode);
+		if (nexp == 2)
+			append_right(subn, node(node(make_number(0.0),
+						     Node_field_spec,
+						     (NODE *) NULL),
+					        Node_expression_list,
+						(NODE *) NULL));
+		else if (do_lint && subn->rnode->rnode->lnode->type == Node_val)
+			warning("string literal as last arg of substitute");
+	} else if (r->proc == do_split) {
+		if (nexp == 2)
+			append_right(subn,
+			    node(FS_node, Node_expression_list, (NODE *) NULL));
+		n = subn->rnode->rnode->lnode;
+		if (n->type != Node_regex)
+			subn->rnode->rnode->lnode = mk_rexp(n);
+		if (nexp == 2)
+			subn->rnode->rnode->lnode->re_flags |= FS_DFLT;
+	}
+
+	r->subnode = subn;
+	return r;
+}
+
+/*
+ * This allocates a Node_line_range node with defined condpair and
+ * zeroes the trigger word to avoid the temptation of assuming that calling
+ * 'node( foo, Node_line_range, 0)' will properly initialize 'triggered'. 
+ */
+/* Otherwise like node() */
+static NODE *
+mkrangenode(cpair)
+NODE *cpair;
+{
+	register NODE *r;
+
+	getnode(r);
+	r->type = Node_line_range;
+	r->condpair = cpair;
+	r->triggered = 0;
+	return r;
+}
+
+/* Build a for loop */
+static NODE *
+make_for_loop(init, cond, incr)
+NODE *init, *cond, *incr;
+{
+	register FOR_LOOP_HEADER *r;
+	NODE *n;
+
+	emalloc(r, FOR_LOOP_HEADER *, sizeof(FOR_LOOP_HEADER), "make_for_loop");
+	getnode(n);
+	n->type = Node_illegal;
+	r->init = init;
+	r->cond = cond;
+	r->incr = incr;
+	n->sub.nodep.r.hd = r;
+	return n;
+}
+
+/*
+ * Install a name in the symbol table, even if it is already there.
+ * Caller must check against redefinition if that is desired. 
+ */
+NODE *
+install(name, value)
+char *name;
+NODE *value;
+{
+	register NODE *hp;
+	register int len, bucket;
+
+	len = strlen(name);
+	bucket = hash(name, len);
+	getnode(hp);
+	hp->type = Node_hashnode;
+	hp->hnext = variables[bucket];
+	variables[bucket] = hp;
+	hp->hlength = len;
+	hp->hvalue = value;
+	hp->hname = name;
+	hp->hvalue->vname = name;
+	return hp->hvalue;
+}
+
+/* find the most recent hash node for name installed by install */
+NODE *
+lookup(name)
+char *name;
+{
+	register NODE *bucket;
+	register int len;
+
+	len = strlen(name);
+	bucket = variables[hash(name, len)];
+	while (bucket) {
+		if (bucket->hlength == len && STREQN(bucket->hname, name, len))
+			return bucket->hvalue;
+		bucket = bucket->hnext;
+	}
+	return NULL;
+}
+
+/*
+ * Add new to the rightmost branch of LIST.  This uses n^2 time, so we make
+ * a simple attempt at optimizing it.
+ */
+static NODE *
+append_right(list, new)
+NODE *list, *new;
+{
+	register NODE *oldlist;
+	static NODE *savefront = NULL, *savetail = NULL;
+
+	oldlist = list;
+	if (savefront == oldlist) {
+		savetail = savetail->rnode = new;
+		return oldlist;
+	} else
+		savefront = oldlist;
+	while (list->rnode != NULL)
+		list = list->rnode;
+	savetail = list->rnode = new;
+	return oldlist;
+}
+
+/*
+ * check if name is already installed;  if so, it had better have Null value,
+ * in which case def is added as the value. Otherwise, install name with def
+ * as value. 
+ */
+static void
+func_install(params, def)
+NODE *params;
+NODE *def;
+{
+	NODE *r;
+
+	pop_params(params->rnode);
+	pop_var(params, 0);
+	r = lookup(params->param);
+	if (r != NULL) {
+		fatal("function name `%s' previously defined", params->param);
+	} else
+		(void) install(params->param, node(params, Node_func, def));
+}
+
+static void
+pop_var(np, freeit)
+NODE *np;
+int freeit;
+{
+	register NODE *bucket, **save;
+	register int len;
+	char *name;
+
+	name = np->param;
+	len = strlen(name);
+	save = &(variables[hash(name, len)]);
+	for (bucket = *save; bucket; bucket = bucket->hnext) {
+		if (len == bucket->hlength && STREQN(bucket->hname, name, len)) {
+			*save = bucket->hnext;
+			freenode(bucket);
+			if (freeit)
+				free(np->param);
+			return;
+		}
+		save = &(bucket->hnext);
+	}
+}
+
+static void
+pop_params(params)
+NODE *params;
+{
+	register NODE *np;
+
+	for (np = params; np != NULL; np = np->rnode)
+		pop_var(np, 1);
+}
+
+static NODE *
+make_param(name)
+char *name;
+{
+	NODE *r;
+
+	getnode(r);
+	r->type = Node_param_list;
+	r->rnode = NULL;
+	r->param = name;
+	r->param_cnt = param_counter++;
+	return (install(name, r));
+}
+
+/* Name points to a variable name.  Make sure its in the symbol table */
+NODE *
+variable(name, can_free)
+char *name;
+int can_free;
+{
+	register NODE *r;
+	static int env_loaded = 0;
+
+	if (!env_loaded && STREQ(name, "ENVIRON")) {
+		load_environ();
+		env_loaded = 1;
+	}
+	if ((r = lookup(name)) == NULL)
+		r = install(name, node(Nnull_string, Node_var, (NODE *) NULL));
+	else if (can_free)
+		free(name);
+	return r;
+}
+
+static NODE *
+mk_rexp(exp)
+NODE *exp;
+{
+	if (exp->type == Node_regex)
+		return exp;
+	else {
+		NODE *n;
+
+		getnode(n);
+		n->type = Node_regex;
+		n->re_exp = exp;
+		n->re_text = NULL;
+		n->re_reg = NULL;
+		n->re_flags = 0;
+		n->re_cnt = 1;
+		return n;
+	}
+}
diff --git a/gnu/usr.bin/awk/builtin.c b/gnu/usr.bin/awk/builtin.c
new file mode 100644
index 000000000000..9d5e3b302fde
--- /dev/null
+++ b/gnu/usr.bin/awk/builtin.c
@@ -0,0 +1,1133 @@
+/*
+ * builtin.c - Builtin functions and various utility procedures 
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include "awk.h"
+
+
+#ifndef SRANDOM_PROTO
+extern void srandom P((int seed));
+#endif
+#ifndef linux
+extern char *initstate P((unsigned seed, char *state, int n));
+extern char *setstate P((char *state));
+extern long random P((void));
+#endif
+
+extern NODE **fields_arr;
+extern int output_is_tty;
+
+static NODE *sub_common P((NODE *tree, int global));
+
+#ifdef GFMT_WORKAROUND
+char *gfmt P((double g, int prec, char *buf));
+#endif
+
+#ifdef _CRAY
+/* Work around a problem in conversion of doubles to exact integers. */
+#include <float.h>
+#define Floor(n) floor((n) * (1.0 + DBL_EPSILON))
+#define Ceil(n) ceil((n) * (1.0 + DBL_EPSILON))
+
+/* Force the standard C compiler to use the library math functions. */
+extern double exp(double);
+double (*Exp)() = exp;
+#define exp(x) (*Exp)(x)
+extern double log(double);
+double (*Log)() = log;
+#define log(x) (*Log)(x)
+#else
+#define Floor(n) floor(n)
+#define Ceil(n) ceil(n)
+#endif
+
+static void
+efwrite(ptr, size, count, fp, from, rp, flush)
+void *ptr;
+unsigned size, count;
+FILE *fp;
+char *from;
+struct redirect *rp;
+int flush;
+{
+	errno = 0;
+	if (fwrite(ptr, size, count, fp) != count)
+		goto wrerror;
+	if (flush
+	  && ((fp == stdout && output_is_tty)
+	   || (rp && (rp->flag & RED_NOBUF)))) {
+		fflush(fp);
+		if (ferror(fp))
+			goto wrerror;
+	}
+	return;
+
+  wrerror:
+	fatal("%s to \"%s\" failed (%s)", from,
+		rp ? rp->value : "standard output",
+		errno ? strerror(errno) : "reason unknown");
+}
+
+/* Builtin functions */
+NODE *
+do_exp(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	double d, res;
+#ifndef exp
+	double exp P((double));
+#endif
+
+	tmp= tree_eval(tree->lnode);
+	d = force_number(tmp);
+	free_temp(tmp);
+	errno = 0;
+	res = exp(d);
+	if (errno == ERANGE)
+		warning("exp argument %g is out of range", d);
+	return tmp_number((AWKNUM) res);
+}
+
+NODE *
+do_index(tree)
+NODE *tree;
+{
+	NODE *s1, *s2;
+	register char *p1, *p2;
+	register int l1, l2;
+	long ret;
+
+
+	s1 = tree_eval(tree->lnode);
+	s2 = tree_eval(tree->rnode->lnode);
+	force_string(s1);
+	force_string(s2);
+	p1 = s1->stptr;
+	p2 = s2->stptr;
+	l1 = s1->stlen;
+	l2 = s2->stlen;
+	ret = 0;
+	if (IGNORECASE) {
+		while (l1) {
+			if (l2 > l1)
+				break;
+			if (casetable[(int)*p1] == casetable[(int)*p2]
+			    && (l2 == 1 || strncasecmp(p1, p2, l2) == 0)) {
+				ret = 1 + s1->stlen - l1;
+				break;
+			}
+			l1--;
+			p1++;
+		}
+	} else {
+		while (l1) {
+			if (l2 > l1)
+				break;
+			if (*p1 == *p2
+			    && (l2 == 1 || STREQN(p1, p2, l2))) {
+				ret = 1 + s1->stlen - l1;
+				break;
+			}
+			l1--;
+			p1++;
+		}
+	}
+	free_temp(s1);
+	free_temp(s2);
+	return tmp_number((AWKNUM) ret);
+}
+
+NODE *
+do_int(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	double floor P((double));
+	double ceil P((double));
+	double d;
+
+	tmp = tree_eval(tree->lnode);
+	d = force_number(tmp);
+	if (d >= 0)
+		d = Floor(d);
+	else
+		d = Ceil(d);
+	free_temp(tmp);
+	return tmp_number((AWKNUM) d);
+}
+
+NODE *
+do_length(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	int len;
+
+	tmp = tree_eval(tree->lnode);
+	len = force_string(tmp)->stlen;
+	free_temp(tmp);
+	return tmp_number((AWKNUM) len);
+}
+
+NODE *
+do_log(tree)
+NODE *tree;
+{
+	NODE *tmp;
+#ifndef log
+	double log P((double));
+#endif
+	double d, arg;
+
+	tmp = tree_eval(tree->lnode);
+	arg = (double) force_number(tmp);
+	if (arg < 0.0)
+		warning("log called with negative argument %g", arg);
+	d = log(arg);
+	free_temp(tmp);
+	return tmp_number((AWKNUM) d);
+}
+
+/* %e and %f formats are not properly implemented.  Someone should fix them */
+/* Actually, this whole thing should be reimplemented. */
+
+NODE *
+do_sprintf(tree)
+NODE *tree;
+{
+#define bchunk(s,l) if(l) {\
+    while((l)>ofre) {\
+      erealloc(obuf, char *, osiz*2, "do_sprintf");\
+      ofre+=osiz;\
+      osiz*=2;\
+    }\
+    memcpy(obuf+olen,s,(l));\
+    olen+=(l);\
+    ofre-=(l);\
+  }
+
+	/* Is there space for something L big in the buffer? */
+#define chksize(l)  if((l)>ofre) {\
+    erealloc(obuf, char *, osiz*2, "do_sprintf");\
+    ofre+=osiz;\
+    osiz*=2;\
+  }
+
+	/*
+	 * Get the next arg to be formatted.  If we've run out of args,
+	 * return "" (Null string) 
+	 */
+#define parse_next_arg() {\
+  if(!carg) { toofew = 1; break; }\
+  else {\
+	arg=tree_eval(carg->lnode);\
+	carg=carg->rnode;\
+  }\
+ }
+
+	NODE *r;
+	int toofew = 0;
+	char *obuf;
+	int osiz, ofre, olen;
+	static char chbuf[] = "0123456789abcdef";
+	static char sp[] = " ";
+	char *s0, *s1;
+	int n0;
+	NODE *sfmt, *arg;
+	register NODE *carg;
+	long fw, prec, lj, alt, big;
+	long *cur;
+	long val;
+#ifdef sun386		/* Can't cast unsigned (int/long) from ptr->value */
+	long tmp_uval;	/* on 386i 4.0.1 C compiler -- it just hangs */
+#endif
+	unsigned long uval;
+	int sgn;
+	int base;
+	char cpbuf[30];		/* if we have numbers bigger than 30 */
+	char *cend = &cpbuf[30];/* chars, we lose, but seems unlikely */
+	char *cp;
+	char *fill;
+	double tmpval;
+	char *pr_str;
+	int ucasehex = 0;
+	char signchar = 0;
+	int len;
+
+
+	emalloc(obuf, char *, 120, "do_sprintf");
+	osiz = 120;
+	ofre = osiz - 1;
+	olen = 0;
+	sfmt = tree_eval(tree->lnode);
+	sfmt = force_string(sfmt);
+	carg = tree->rnode;
+	for (s0 = s1 = sfmt->stptr, n0 = sfmt->stlen; n0-- > 0;) {
+		if (*s1 != '%') {
+			s1++;
+			continue;
+		}
+		bchunk(s0, s1 - s0);
+		s0 = s1;
+		cur = &fw;
+		fw = 0;
+		prec = 0;
+		lj = alt = big = 0;
+		fill = sp;
+		cp = cend;
+		s1++;
+
+retry:
+		--n0;
+		switch (*s1++) {
+		case '%':
+			bchunk("%", 1);
+			s0 = s1;
+			break;
+
+		case '0':
+			if (fill != sp || lj)
+				goto lose;
+			if (cur == &fw)
+				fill = "0";	/* FALL through */
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7':
+		case '8':
+		case '9':
+			if (cur == 0)
+				goto lose;
+			*cur = s1[-1] - '0';
+			while (n0 > 0 && *s1 >= '0' && *s1 <= '9') {
+				--n0;
+				*cur = *cur * 10 + *s1++ - '0';
+			}
+			goto retry;
+		case '*':
+			if (cur == 0)
+				goto lose;
+			parse_next_arg();
+			*cur = force_number(arg);
+			free_temp(arg);
+			goto retry;
+		case ' ':		/* print ' ' or '-' */
+		case '+':		/* print '+' or '-' */
+			signchar = *(s1-1);
+			goto retry;
+		case '-':
+			if (lj || fill != sp)
+				goto lose;
+			lj++;
+			goto retry;
+		case '.':
+			if (cur != &fw)
+				goto lose;
+			cur = &prec;
+			goto retry;
+		case '#':
+			if (alt)
+				goto lose;
+			alt++;
+			goto retry;
+		case 'l':
+			if (big)
+				goto lose;
+			big++;
+			goto retry;
+		case 'c':
+			parse_next_arg();
+			if (arg->flags & NUMBER) {
+#ifdef sun386
+				tmp_uval = arg->numbr; 
+				uval= (unsigned long) tmp_uval;
+#else
+				uval = (unsigned long) arg->numbr;
+#endif
+				cpbuf[0] = uval;
+				prec = 1;
+				pr_str = cpbuf;
+				goto dopr_string;
+			}
+			if (! prec)
+				prec = 1;
+			else if (prec > arg->stlen)
+				prec = arg->stlen;
+			pr_str = arg->stptr;
+			goto dopr_string;
+		case 's':
+			parse_next_arg();
+			arg = force_string(arg);
+			if (!prec || prec > arg->stlen)
+				prec = arg->stlen;
+			pr_str = arg->stptr;
+
+	dopr_string:
+			if (fw > prec && !lj) {
+				while (fw > prec) {
+					bchunk(sp, 1);
+					fw--;
+				}
+			}
+			bchunk(pr_str, (int) prec);
+			if (fw > prec) {
+				while (fw > prec) {
+					bchunk(sp, 1);
+					fw--;
+				}
+			}
+			s0 = s1;
+			free_temp(arg);
+			break;
+		case 'd':
+		case 'i':
+			parse_next_arg();
+			val = (long) force_number(arg);
+			free_temp(arg);
+			if (val < 0) {
+				sgn = 1;
+				val = -val;
+			} else
+				sgn = 0;
+			do {
+				*--cp = '0' + val % 10;
+				val /= 10;
+			} while (val);
+			if (sgn)
+				*--cp = '-';
+			else if (signchar)
+				*--cp = signchar;
+			if (prec > fw)
+				fw = prec;
+			prec = cend - cp;
+			if (fw > prec && !lj) {
+				if (fill != sp && (*cp == '-' || signchar)) {
+					bchunk(cp, 1);
+					cp++;
+					prec--;
+					fw--;
+				}
+				while (fw > prec) {
+					bchunk(fill, 1);
+					fw--;
+				}
+			}
+			bchunk(cp, (int) prec);
+			if (fw > prec) {
+				while (fw > prec) {
+					bchunk(fill, 1);
+					fw--;
+				}
+			}
+			s0 = s1;
+			break;
+		case 'u':
+			base = 10;
+			goto pr_unsigned;
+		case 'o':
+			base = 8;
+			goto pr_unsigned;
+		case 'X':
+			ucasehex = 1;
+		case 'x':
+			base = 16;
+			goto pr_unsigned;
+	pr_unsigned:
+			parse_next_arg();
+			uval = (unsigned long) force_number(arg);
+			free_temp(arg);
+			do {
+				*--cp = chbuf[uval % base];
+				if (ucasehex && isalpha(*cp))
+					*cp = toupper(*cp);
+				uval /= base;
+			} while (uval);
+			if (alt && (base == 8 || base == 16)) {
+				if (base == 16) {
+					if (ucasehex)
+						*--cp = 'X';
+					else
+						*--cp = 'x';
+				}
+				*--cp = '0';
+			}
+			prec = cend - cp;
+			if (fw > prec && !lj) {
+				while (fw > prec) {
+					bchunk(fill, 1);
+					fw--;
+				}
+			}
+			bchunk(cp, (int) prec);
+			if (fw > prec) {
+				while (fw > prec) {
+					bchunk(fill, 1);
+					fw--;
+				}
+			}
+			s0 = s1;
+			break;
+		case 'g':
+			parse_next_arg();
+			tmpval = force_number(arg);
+			free_temp(arg);
+			chksize(fw + prec + 9);	/* 9==slop */
+
+			cp = cpbuf;
+			*cp++ = '%';
+			if (lj)
+				*cp++ = '-';
+			if (fill != sp)
+				*cp++ = '0';
+#ifndef GFMT_WORKAROUND
+			if (cur != &fw) {
+				(void) strcpy(cp, "*.*g");
+				(void) sprintf(obuf + olen, cpbuf, (int) fw, (int) prec, (double) tmpval);
+			} else {
+				(void) strcpy(cp, "*g");
+				(void) sprintf(obuf + olen, cpbuf, (int) fw, (double) tmpval);
+			}
+#else	/* GFMT_WORKAROUND */
+		      {
+			char *gptr, gbuf[120];
+#define DEFAULT_G_PRECISION 6
+			if (fw + prec + 9 > sizeof gbuf) {	/* 9==slop */
+				emalloc(gptr, char *, fw+prec+9, "do_sprintf(gfmt)");
+			} else
+				gptr = gbuf;
+			(void) gfmt((double) tmpval, cur != &fw ?
+				    (int) prec : DEFAULT_G_PRECISION, gptr);
+			*cp++ = '*',  *cp++ = 's',  *cp = '\0';
+			(void) sprintf(obuf + olen, cpbuf, (int) fw, gptr);
+			if (fill != sp && *gptr == ' ') {
+				char *p = gptr;
+				do { *p++ = '0'; } while (*p == ' ');
+			}
+			if (gptr != gbuf) free(gptr);
+		      }
+#endif	/* GFMT_WORKAROUND */
+			len = strlen(obuf + olen);
+			ofre -= len;
+			olen += len;
+			s0 = s1;
+			break;
+
+		case 'f':
+			parse_next_arg();
+			tmpval = force_number(arg);
+			free_temp(arg);
+			chksize(fw + prec + 9);	/* 9==slop */
+
+			cp = cpbuf;
+			*cp++ = '%';
+			if (lj)
+				*cp++ = '-';
+			if (fill != sp)
+				*cp++ = '0';
+			if (cur != &fw) {
+				(void) strcpy(cp, "*.*f");
+				(void) sprintf(obuf + olen, cpbuf, (int) fw, (int) prec, (double) tmpval);
+			} else {
+				(void) strcpy(cp, "*f");
+				(void) sprintf(obuf + olen, cpbuf, (int) fw, (double) tmpval);
+			}
+			len = strlen(obuf + olen);
+			ofre -= len;
+			olen += len;
+			s0 = s1;
+			break;
+		case 'e':
+			parse_next_arg();
+			tmpval = force_number(arg);
+			free_temp(arg);
+			chksize(fw + prec + 9);	/* 9==slop */
+			cp = cpbuf;
+			*cp++ = '%';
+			if (lj)
+				*cp++ = '-';
+			if (fill != sp)
+				*cp++ = '0';
+			if (cur != &fw) {
+				(void) strcpy(cp, "*.*e");
+				(void) sprintf(obuf + olen, cpbuf, (int) fw, (int) prec, (double) tmpval);
+			} else {
+				(void) strcpy(cp, "*e");
+				(void) sprintf(obuf + olen, cpbuf, (int) fw, (double) tmpval);
+			}
+			len = strlen(obuf + olen);
+			ofre -= len;
+			olen += len;
+			s0 = s1;
+			break;
+
+		default:
+	lose:
+			break;
+		}
+		if (toofew)
+			fatal("%s\n\t%s\n\t%*s%s",
+			"not enough arguments to satisfy format string",
+			sfmt->stptr, s1 - sfmt->stptr - 2, "",
+			"^ ran out for this one"
+			);
+	}
+	if (do_lint && carg != NULL)
+		warning("too many arguments supplied for format string");
+	bchunk(s0, s1 - s0);
+	free_temp(sfmt);
+	r = make_str_node(obuf, olen, ALREADY_MALLOCED);
+	r->flags |= TEMP;
+	return r;
+}
+
+void
+do_printf(tree)
+register NODE *tree;
+{
+	struct redirect *rp = NULL;
+	register FILE *fp;
+
+	if (tree->rnode) {
+		int errflg;	/* not used, sigh */
+
+		rp = redirect(tree->rnode, &errflg);
+		if (rp) {
+			fp = rp->fp;
+			if (!fp)
+				return;
+		} else
+			return;
+	} else
+		fp = stdout;
+	tree = do_sprintf(tree->lnode);
+	efwrite(tree->stptr, sizeof(char), tree->stlen, fp, "printf", rp , 1);
+	free_temp(tree);
+}
+
+NODE *
+do_sqrt(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	double arg;
+	extern double sqrt P((double));
+
+	tmp = tree_eval(tree->lnode);
+	arg = (double) force_number(tmp);
+	free_temp(tmp);
+	if (arg < 0.0)
+		warning("sqrt called with negative argument %g", arg);
+	return tmp_number((AWKNUM) sqrt(arg));
+}
+
+NODE *
+do_substr(tree)
+NODE *tree;
+{
+	NODE *t1, *t2, *t3;
+	NODE *r;
+	register int indx;
+	size_t length;
+
+	t1 = tree_eval(tree->lnode);
+	t2 = tree_eval(tree->rnode->lnode);
+	if (tree->rnode->rnode == NULL)	/* third arg. missing */
+		length = t1->stlen;
+	else {
+		t3 = tree_eval(tree->rnode->rnode->lnode);
+		length = (size_t) force_number(t3);
+		free_temp(t3);
+	}
+	indx = (int) force_number(t2) - 1;
+	free_temp(t2);
+	t1 = force_string(t1);
+	if (indx < 0)
+		indx = 0;
+	if (indx >= t1->stlen || length <= 0) {
+		free_temp(t1);
+		return Nnull_string;
+	}
+	if (indx + length > t1->stlen || LONG_MAX - indx < length)
+		length = t1->stlen - indx;
+	r =  tmp_string(t1->stptr + indx, length);
+	free_temp(t1);
+	return r;
+}
+
+NODE *
+do_strftime(tree)
+NODE *tree;
+{
+	NODE *t1, *t2;
+	struct tm *tm;
+	time_t fclock;
+	char buf[100];
+	int ret;
+
+	t1 = force_string(tree_eval(tree->lnode));
+
+	if (tree->rnode == NULL)	/* second arg. missing, default */
+		(void) time(&fclock);
+	else {
+		t2 = tree_eval(tree->rnode->lnode);
+		fclock = (time_t) force_number(t2);
+		free_temp(t2);
+	}
+	tm = localtime(&fclock);
+
+	ret = strftime(buf, 100, t1->stptr, tm);
+
+	return tmp_string(buf, ret);
+}
+
+NODE *
+do_systime(tree)
+NODE *tree;
+{
+	time_t lclock;
+
+	(void) time(&lclock);
+	return tmp_number((AWKNUM) lclock);
+}
+
+NODE *
+do_system(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	int ret = 0;
+	char *cmd;
+
+	(void) flush_io ();	/* so output is synchronous with gawk's */
+	tmp = tree_eval(tree->lnode);
+	cmd = force_string(tmp)->stptr;
+	if (cmd && *cmd) {
+		ret = system(cmd);
+		ret = (ret >> 8) & 0xff;
+	}
+	free_temp(tmp);
+	return tmp_number((AWKNUM) ret);
+}
+
+void 
+do_print(tree)
+register NODE *tree;
+{
+	register NODE *t1;
+	struct redirect *rp = NULL;
+	register FILE *fp;
+	register char *s;
+
+	if (tree->rnode) {
+		int errflg;		/* not used, sigh */
+
+		rp = redirect(tree->rnode, &errflg);
+		if (rp) {
+			fp = rp->fp;
+			if (!fp)
+				return;
+		} else
+			return;
+	} else
+		fp = stdout;
+	tree = tree->lnode;
+	while (tree) {
+		t1 = tree_eval(tree->lnode);
+		if (t1->flags & NUMBER) {
+			if (OFMTidx == CONVFMTidx)
+				(void) force_string(t1);
+			else {
+				char buf[100];
+
+				sprintf(buf, OFMT, t1->numbr);
+				t1 = tmp_string(buf, strlen(buf));
+			}
+		}
+		efwrite(t1->stptr, sizeof(char), t1->stlen, fp, "print", rp, 0);
+		free_temp(t1);
+		tree = tree->rnode;
+		if (tree) {
+			s = OFS;
+			if (OFSlen)
+				efwrite(s, sizeof(char), OFSlen, fp, "print", rp, 0);
+		}
+	}
+	s = ORS;
+	if (ORSlen)
+		efwrite(s, sizeof(char), ORSlen, fp, "print", rp, 1);
+}
+
+NODE *
+do_tolower(tree)
+NODE *tree;
+{
+	NODE *t1, *t2;
+	register char *cp, *cp2;
+
+	t1 = tree_eval(tree->lnode);
+	t1 = force_string(t1);
+	t2 = tmp_string(t1->stptr, t1->stlen);
+	for (cp = t2->stptr, cp2 = t2->stptr + t2->stlen; cp < cp2; cp++)
+		if (isupper(*cp))
+			*cp = tolower(*cp);
+	free_temp(t1);
+	return t2;
+}
+
+NODE *
+do_toupper(tree)
+NODE *tree;
+{
+	NODE *t1, *t2;
+	register char *cp;
+
+	t1 = tree_eval(tree->lnode);
+	t1 = force_string(t1);
+	t2 = tmp_string(t1->stptr, t1->stlen);
+	for (cp = t2->stptr; cp < t2->stptr + t2->stlen; cp++)
+		if (islower(*cp))
+			*cp = toupper(*cp);
+	free_temp(t1);
+	return t2;
+}
+
+NODE *
+do_atan2(tree)
+NODE *tree;
+{
+	NODE *t1, *t2;
+	extern double atan2 P((double, double));
+	double d1, d2;
+
+	t1 = tree_eval(tree->lnode);
+	t2 = tree_eval(tree->rnode->lnode);
+	d1 = force_number(t1);
+	d2 = force_number(t2);
+	free_temp(t1);
+	free_temp(t2);
+	return tmp_number((AWKNUM) atan2(d1, d2));
+}
+
+NODE *
+do_sin(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	extern double sin P((double));
+	double d;
+
+	tmp = tree_eval(tree->lnode);
+	d = sin((double)force_number(tmp));
+	free_temp(tmp);
+	return tmp_number((AWKNUM) d);
+}
+
+NODE *
+do_cos(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	extern double cos P((double));
+	double d;
+
+	tmp = tree_eval(tree->lnode);
+	d = cos((double)force_number(tmp));
+	free_temp(tmp);
+	return tmp_number((AWKNUM) d);
+}
+
+static int firstrand = 1;
+static char state[256];
+
+/* ARGSUSED */
+NODE *
+do_rand(tree)
+NODE *tree;
+{
+	if (firstrand) {
+		(void) initstate((unsigned) 1, state, sizeof state);
+		srandom(1);
+		firstrand = 0;
+	}
+	return tmp_number((AWKNUM) random() / LONG_MAX);
+}
+
+NODE *
+do_srand(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	static long save_seed = 0;
+	long ret = save_seed;	/* SVR4 awk srand returns previous seed */
+
+	if (firstrand)
+		(void) initstate((unsigned) 1, state, sizeof state);
+	else
+		(void) setstate(state);
+
+	if (!tree)
+		srandom((int) (save_seed = (long) time((time_t *) 0)));
+	else {
+		tmp = tree_eval(tree->lnode);
+		srandom((int) (save_seed = (long) force_number(tmp)));
+		free_temp(tmp);
+	}
+	firstrand = 0;
+	return tmp_number((AWKNUM) ret);
+}
+
+NODE *
+do_match(tree)
+NODE *tree;
+{
+	NODE *t1;
+	int rstart;
+	AWKNUM rlength;
+	Regexp *rp;
+
+	t1 = force_string(tree_eval(tree->lnode));
+	tree = tree->rnode->lnode;
+	rp = re_update(tree);
+	rstart = research(rp, t1->stptr, 0, t1->stlen, 1);
+	if (rstart >= 0) {	/* match succeded */
+		rstart++;	/* 1-based indexing */
+		rlength = REEND(rp, t1->stptr) - RESTART(rp, t1->stptr);
+	} else {		/* match failed */
+		rstart = 0;
+		rlength = -1.0;
+	}
+	free_temp(t1);
+	unref(RSTART_node->var_value);
+	RSTART_node->var_value = make_number((AWKNUM) rstart);
+	unref(RLENGTH_node->var_value);
+	RLENGTH_node->var_value = make_number(rlength);
+	return tmp_number((AWKNUM) rstart);
+}
+
+static NODE *
+sub_common(tree, global)
+NODE *tree;
+int global;
+{
+	register char *scan;
+	register char *bp, *cp;
+	char *buf;
+	int buflen;
+	register char *matchend;
+	register int len;
+	char *matchstart;
+	char *text;
+	int textlen;
+	char *repl;
+	char *replend;
+	int repllen;
+	int sofar;
+	int ampersands;
+	int matches = 0;
+	Regexp *rp;
+	NODE *s;		/* subst. pattern */
+	NODE *t;		/* string to make sub. in; $0 if none given */
+	NODE *tmp;
+	NODE **lhs = &tree;	/* value not used -- just different from NULL */
+	int priv = 0;
+	Func_ptr after_assign = NULL;
+
+	tmp = tree->lnode;
+	rp = re_update(tmp);
+
+	tree = tree->rnode;
+	s = tree->lnode;
+
+	tree = tree->rnode;
+	tmp = tree->lnode;
+	t = force_string(tree_eval(tmp));
+
+	/* do the search early to avoid work on non-match */
+	if (research(rp, t->stptr, 0, t->stlen, 1) == -1 ||
+	    (RESTART(rp, t->stptr) > t->stlen) && (matches = 1)) {
+		free_temp(t);
+		return tmp_number((AWKNUM) matches);
+	}
+
+	if (tmp->type == Node_val)
+		lhs = NULL;
+	else
+		lhs = get_lhs(tmp, &after_assign);
+	t->flags |= STRING;
+	/*
+	 * create a private copy of the string
+	 */
+	if (t->stref > 1 || (t->flags & PERM)) {
+		unsigned int saveflags;
+
+		saveflags = t->flags;
+		t->flags &= ~MALLOC;
+		tmp = dupnode(t);
+		t->flags = saveflags;
+		t = tmp;
+		priv = 1;
+	}
+	text = t->stptr;
+	textlen = t->stlen;
+	buflen = textlen + 2;
+
+	s = force_string(tree_eval(s));
+	repl = s->stptr;
+	replend = repl + s->stlen;
+	repllen = replend - repl;
+	emalloc(buf, char *, buflen, "do_sub");
+	ampersands = 0;
+	for (scan = repl; scan < replend; scan++) {
+		if (*scan == '&') {
+			repllen--;
+			ampersands++;
+		} else if (*scan == '\\' && (*(scan+1) == '&' || *(scan+1) == '\\')) {
+			repllen--;
+			scan++;
+		}
+	}
+
+	bp = buf;
+	for (;;) {
+		matches++;
+		matchstart = t->stptr + RESTART(rp, t->stptr);
+		matchend = t->stptr + REEND(rp, t->stptr);
+
+		/*
+		 * create the result, copying in parts of the original
+		 * string 
+		 */
+		len = matchstart - text + repllen
+		      + ampersands * (matchend - matchstart);
+		sofar = bp - buf;
+		while (buflen - sofar - len - 1 < 0) {
+			buflen *= 2;
+			erealloc(buf, char *, buflen, "do_sub");
+			bp = buf + sofar;
+		}
+		for (scan = text; scan < matchstart; scan++)
+			*bp++ = *scan;
+		for (scan = repl; scan < replend; scan++)
+			if (*scan == '&')
+				for (cp = matchstart; cp < matchend; cp++)
+					*bp++ = *cp;
+			else if (*scan == '\\' && (*(scan+1) == '&' || *(scan+1) == '\\')) {
+				scan++;
+				*bp++ = *scan;
+			} else
+				*bp++ = *scan;
+		if (global && matchstart == matchend && matchend < text + textlen) {
+			*bp++ = *matchend;
+			matchend++;
+		}
+		textlen = text + textlen - matchend;
+		text = matchend;
+		if (!global || textlen <= 0 ||
+		    research(rp, t->stptr, text-t->stptr, textlen, 1) == -1)
+			break;
+	}
+	sofar = bp - buf;
+	if (buflen - sofar - textlen - 1) {
+		buflen = sofar + textlen + 2;
+		erealloc(buf, char *, buflen, "do_sub");
+		bp = buf + sofar;
+	}
+	for (scan = matchend; scan < text + textlen; scan++)
+		*bp++ = *scan;
+	textlen = bp - buf;
+	free(t->stptr);
+	t->stptr = buf;
+	t->stlen = textlen;
+
+	free_temp(s);
+	if (matches > 0 && lhs) {
+		if (priv) {
+			unref(*lhs);
+			*lhs = t;
+		}
+		if (after_assign)
+			(*after_assign)();
+		t->flags &= ~(NUM|NUMBER);
+	}
+	return tmp_number((AWKNUM) matches);
+}
+
+NODE *
+do_gsub(tree)
+NODE *tree;
+{
+	return sub_common(tree, 1);
+}
+
+NODE *
+do_sub(tree)
+NODE *tree;
+{
+	return sub_common(tree, 0);
+}
+
+#ifdef GFMT_WORKAROUND
+	/*
+	 *	printf's %g format [can't rely on gcvt()]
+	 *		caveat: don't use as argument to *printf()!
+	 */
+char *
+gfmt(g, prec, buf)
+double g;	/* value to format */
+int prec;	/* indicates desired significant digits, not decimal places */
+char *buf;	/* return buffer; assumed big enough to hold result */
+{
+	if (g == 0.0) {
+		(void) strcpy(buf, "0");	/* easy special case */
+	} else {
+		register char *d, *e, *p;
+
+		/* start with 'e' format (it'll provide nice exponent) */
+		if (prec < 1) prec = 1;	    /* at least 1 significant digit */
+		(void) sprintf(buf, "%.*e", prec - 1, g);
+		if ((e = strchr(buf, 'e')) != 0) {	/* find exponent  */
+			int exp = atoi(e+1);		/* fetch exponent */
+			if (exp >= -4 && exp < prec) {	/* per K&R2, B1.2 */
+				/* switch to 'f' format and re-do */
+				prec -= (exp + 1);	/* decimal precision */
+				(void) sprintf(buf, "%.*f", prec, g);
+				e = buf + strlen(buf);
+			}
+			if ((d = strchr(buf, '.')) != 0) {
+				/* remove trailing zeroes and decimal point */
+				for (p = e; p > d && *--p == '0'; ) continue;
+				if (*p == '.') --p;
+				if (++p < e)	/* copy exponent and NUL */
+					while ((*p++ = *e++) != '\0') continue;
+			}
+		}
+	}
+	return buf;
+}
+#endif	/* GFMT_WORKAROUND */
diff --git a/gnu/usr.bin/awk/config.h b/gnu/usr.bin/awk/config.h
new file mode 100644
index 000000000000..8c20953ed531
--- /dev/null
+++ b/gnu/usr.bin/awk/config.h
@@ -0,0 +1,272 @@
+/*
+ * config.h -- configuration definitions for gawk.
+ *
+ * For generic 4.4 alpha
+ */
+
+/* 
+ * Copyright (C) 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * This file isolates configuration dependencies for gnu awk.
+ * You should know something about your system, perhaps by having
+ * a manual handy, when you edit this file.  You should copy config.h-dist
+ * to config.h, and edit config.h.  Do not modify config.h-dist, so that
+ * it will be easy to apply any patches that may be distributed.
+ *
+ * The general idea is that systems conforming to the various standards
+ * should need to do the least amount of changing.  Definining the various
+ * items in ths file usually means that your system is missing that
+ * particular feature.
+ *
+ * The order of preference in standard conformance is ANSI C, POSIX,
+ * and the SVID.
+ *
+ * If you have no clue as to what's going on with your system, try
+ * compiling gawk without editing this file and see what shows up
+ * missing in the link stage.  From there, you can probably figure out
+ * which defines to turn on.
+ */
+
+/**************************/
+/* Miscellanious features */
+/**************************/
+
+/*
+ * BLKSIZE_MISSING
+ *
+ * Check your /usr/include/sys/stat.h file.  If the stat structure
+ * does not have a member named st_blksize, define this.  (This will
+ * most likely be the case on most System V systems prior to V.4.)
+ */
+/* #define BLKSIZE_MISSING	1 */
+
+/*
+ * SIGTYPE
+ *
+ * The return type of the routines passed to the signal function.
+ * Modern systems use `void', older systems use `int'.
+ * If left undefined, it will default to void.
+ */
+/* #define SIGTYPE	int */
+
+/*
+ * SIZE_T_MISSING
+ *
+ * If your system has no typedef for size_t, define this to get a default
+ */
+/* #define	SIZE_T_MISSING	1 */
+
+/*
+ * CHAR_UNSIGNED
+ *
+ * If your machine uses unsigned characters (IBM RT and RS/6000 and others)
+ * then define this for use in regex.c
+ */
+/* #define CHAR_UNSIGNED	1 */
+
+/*
+ * HAVE_UNDERSCORE_SETJMP
+ *
+ * Check in your /usr/include/setjmp.h file.  If there are routines
+ * there named _setjmp and _longjmp, then you should define this.
+ * Typically only systems derived from Berkeley Unix have this.
+ */
+#define	HAVE_UNDERSCORE_SETJMP	1
+
+/***********************************************/
+/* Missing library subroutines or system calls */
+/***********************************************/
+
+/*
+ * MEMCMP_MISSING
+ * MEMCPY_MISSING
+ * MEMSET_MISSING
+ *
+ * These three routines are for manipulating blocks of memory. Most
+ * likely they will either all three be present or all three be missing,
+ * so they're grouped together.
+ */
+/* #define MEMCMP_MISSING	1 */
+/* #define MEMCPY_MISSING	1 */
+/* #define MEMSET_MISSING	1 */
+
+/*
+ * RANDOM_MISSING
+ *
+ * Your system does not have the random(3) suite of random number
+ * generating routines.  These are different than the old rand(3)
+ * routines!
+ */
+/* #define RANDOM_MISSING	1 */
+
+/*
+ * STRCASE_MISSING
+ *
+ * Your system does not have the strcasemp() and strncasecmp()
+ * routines that originated in Berkeley Unix.
+ */
+/* #define STRCASE_MISSING	1 */
+
+/*
+ * STRCHR_MISSING
+ *
+ * Your system does not have the strchr() and strrchr() functions.
+ */
+/* #define STRCHR_MISSING	1 */
+
+/*
+ * STRERROR_MISSING
+ *
+ * Your system lacks the ANSI C strerror() routine for returning the
+ * strings associated with errno values.
+ */
+/* #define STRERROR_MISSING	1 */
+
+/*
+ * STRTOD_MISSING
+ *
+ * Your system does not have the strtod() routine for converting
+ * strings to double precision floating point values.
+ */
+/* #define	STRTOD_MISSING  1 */
+
+/*
+ * STRFTIME_MISSING
+ *
+ * Your system lacks the ANSI C strftime() routine for formatting
+ * broken down time values.
+ */
+/* #define STRFTIME_MISSING	1 */
+
+/*
+ * TZSET_MISSING
+ *
+ * If you have a 4.2 BSD vintage system, then the strftime() routine
+ * supplied in the missing directory won't be enough, because it relies on the
+ * tzset() routine from System V / Posix.  Fortunately, there is an
+ * emulation for tzset() too that should do the trick.  If you don't
+ * have tzset(), define this.
+ */
+/* #define TZSET_MISSING	1 */
+
+/*
+ * TZNAME_MISSING
+ *
+ * Some systems do not support the external variables tzname and daylight.
+ * If this is the case *and* strftime() is missing, define this.
+ */
+/* #define TZNAME_MISSING	1 */
+
+/*
+ * STDC_HEADERS
+ *
+ * If your system does have ANSI compliant header files that
+ * provide prototypes for library routines, then define this.
+ */
+#define	STDC_HEADERS    1
+
+/*
+ * NO_TOKEN_PASTING
+ *
+ * If your compiler define's __STDC__ but does not support token
+ * pasting (tok##tok), then define this.
+ */
+/* #define NO_TOKEN_PASTING	1 */
+
+/*****************************************************************/
+/* Stuff related to the Standard I/O Library.			 */
+/*****************************************************************/
+/* Much of this is (still, unfortunately) black magic in nature. */
+/* You may have to use some or all of these together to get gawk */
+/* to work correctly.						 */
+/*****************************************************************/
+
+/*
+ * NON_STD_SPRINTF
+ *
+ * Look in your /usr/include/stdio.h file.  If the return type of the
+ * sprintf() function is NOT `int', define this.
+ */
+/* #define NON_STD_SPRINTF	1 */
+
+/*
+ * VPRINTF_MISSING
+ *
+ * Define this if your system lacks vprintf() and the other routines
+ * that go with it.  This will trigger an attempt to use _doprnt().
+ * If you don't have that, this attempt will fail and you are on your own.
+ */
+/* #define VPRINTF_MISSING	1 */
+
+/*
+ * Casts from size_t to int and back.  These will become unnecessary
+ * at some point in the future, but for now are required where the
+ * two types are a different representation.
+ */
+/* #define SZTC */
+/* #define INTC */
+
+/*
+ * SYSTEM_MISSING
+ *
+ * Define this if your library does not provide a system function
+ * or you are not entirely happy with it and would rather use
+ * a provided replacement (atari only).
+ */
+/* #define SYSTEM_MISSING   1 */
+
+/*
+ * FMOD_MISSING
+ *
+ * Define this if your system lacks the fmod() function and modf() will
+ * be used instead.
+ */
+/* #define FMOD_MISSING	1 */
+
+
+/*******************************/
+/* Gawk configuration options. */
+/*******************************/
+
+/*
+ * DEFPATH
+ *
+ * The default search path for the -f option of gawk.  It is used
+ * if the AWKPATH environment variable is undefined.  The default
+ * definition is provided here.  Most likely you should not change
+ * this.
+ */
+
+/* #define DEFPATH	".:/usr/lib/awk:/usr/local/lib/awk" */
+/* #define ENVSEP	':' */
+
+/*
+ * alloca already has a prototype defined - don't redefine it
+ */
+#define	ALLOCA_PROTO	1
+
+/*
+ * srandom already has a prototype defined - don't redefine it
+ */
+#define	SRANDOM_PROTO	1
+
+/* anything that follows is for system-specific short-term kludges */
diff --git a/gnu/usr.bin/awk/dfa.c b/gnu/usr.bin/awk/dfa.c
new file mode 100644
index 000000000000..5293c755871d
--- /dev/null
+++ b/gnu/usr.bin/awk/dfa.c
@@ -0,0 +1,2291 @@
+/* dfa.c - determinisitic extended regexp routines for GNU
+   Copyright (C) 1988 Free Software Foundation, Inc.
+                      Written June, 1988 by Mike Haertel
+		      Modified July, 1988 by Arthur David Olson
+			 to assist BMG speedups
+
+		       NO WARRANTY
+
+  BECAUSE THIS PROGRAM IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY
+NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW.  EXCEPT
+WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC,
+RICHARD M. STALLMAN AND/OR OTHER PARTIES PROVIDE THIS PROGRAM "AS IS"
+WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY
+AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE PROGRAM PROVE
+DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
+CORRECTION.
+
+ IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL RICHARD M.
+STALLMAN, THE FREE SOFTWARE FOUNDATION, INC., AND/OR ANY OTHER PARTY
+WHO MAY MODIFY AND REDISTRIBUTE THIS PROGRAM AS PERMITTED BELOW, BE
+LIABLE TO YOU FOR DAMAGES, INCLUDING ANY LOST PROFITS, LOST MONIES, OR
+OTHER SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR
+DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES OR
+A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) THIS
+PROGRAM, EVEN IF YOU HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
+DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY.
+
+		GENERAL PUBLIC LICENSE TO COPY
+
+  1. You may copy and distribute verbatim copies of this source file
+as you receive it, in any medium, provided that you conspicuously and
+appropriately publish on each copy a valid copyright notice "Copyright
+ (C) 1988 Free Software Foundation, Inc."; and include following the
+copyright notice a verbatim copy of the above disclaimer of warranty
+and of this License.  You may charge a distribution fee for the
+physical act of transferring a copy.
+
+  2. You may modify your copy or copies of this source file or
+any portion of it, and copy and distribute such modifications under
+the terms of Paragraph 1 above, provided that you also do the following:
+
+    a) cause the modified files to carry prominent notices stating
+    that you changed the files and the date of any change; and
+
+    b) cause the whole of any work that you distribute or publish,
+    that in whole or in part contains or is a derivative of this
+    program or any part thereof, to be licensed at no charge to all
+    third parties on terms identical to those contained in this
+    License Agreement (except that you may choose to grant more extensive
+    warranty protection to some or all third parties, at your option).
+
+    c) You may charge a distribution fee for the physical act of
+    transferring a copy, and you may at your option offer warranty
+    protection in exchange for a fee.
+
+Mere aggregation of another unrelated program with this program (or its
+derivative) on a volume of a storage or distribution medium does not bring
+the other program under the scope of these terms.
+
+  3. You may copy and distribute this program or any portion of it in
+compiled, executable or object code form under the terms of Paragraphs
+1 and 2 above provided that you do the following:
+
+    a) accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of
+    Paragraphs 1 and 2 above; or,
+
+    b) accompany it with a written offer, valid for at least three
+    years, to give any third party free (except for a nominal
+    shipping charge) a complete machine-readable copy of the
+    corresponding source code, to be distributed under the terms of
+    Paragraphs 1 and 2 above; or,
+
+    c) accompany it with the information you received as to where the
+    corresponding source code may be obtained.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form alone.)
+
+For an executable file, complete source code means all the source code for
+all modules it contains; but, as a special exception, it need not include
+source code for modules which are standard libraries that accompany the
+operating system on which the executable file runs.
+
+  4. You may not copy, sublicense, distribute or transfer this program
+except as expressly provided under this License Agreement.  Any attempt
+otherwise to copy, sublicense, distribute or transfer this program is void and
+your rights to use the program under this License agreement shall be
+automatically terminated.  However, parties who have received computer
+software programs from you with this License Agreement will not have
+their licenses terminated so long as such parties remain in full compliance.
+
+  5. If you wish to incorporate parts of this program into other free
+programs whose distribution conditions are different, write to the Free
+Software Foundation at 675 Mass Ave, Cambridge, MA 02139.  We have not yet
+worked out a simple rule that can be stated here, but we will often permit
+this.  We will be guided by the two goals of preserving the free status of
+all derivatives our free software and of promoting the sharing and reuse of
+software.
+
+
+In other words, you are welcome to use, share and improve this program.
+You are forbidden to forbid anyone else to use, share and improve
+what you give them.   Help stamp out software-hoarding!  */
+
+#include "awk.h"
+#include <assert.h>
+
+#ifdef setbit  /* surprise - setbit and clrbit are macros on NeXT */
+#undef setbit
+#endif
+#ifdef clrbit
+#undef clrbit
+#endif
+
+#ifdef __STDC__
+typedef void *ptr_t;
+#else
+typedef char *ptr_t;
+#endif
+
+typedef struct {
+	char **	in;
+	char *	left;
+	char *	right;
+	char *	is;
+} must;
+
+static ptr_t xcalloc P((int n, size_t s));
+static ptr_t xmalloc P((size_t n));
+static ptr_t xrealloc P((ptr_t p, size_t n));
+static int tstbit P((int b, _charset c));
+static void setbit P((int b, _charset c));
+static void clrbit P((int b, _charset c));
+static void copyset P((const _charset src, _charset dst));
+static void zeroset P((_charset s));
+static void notset P((_charset s));
+static int equal P((const _charset s1, const _charset s2));
+static int charset_index P((const _charset s));
+static _token lex P((void));
+static void addtok P((_token t));
+static void atom P((void));
+static void closure P((void));
+static void branch P((void));
+static void regexp P((void));
+static void copy P((const _position_set *src, _position_set *dst));
+static void insert P((_position p, _position_set *s));
+static void merge P((_position_set *s1, _position_set *s2, _position_set *m));
+static void delete P((_position p, _position_set *s));
+static int state_index P((struct regexp *r, _position_set *s,
+			  int newline, int letter));
+static void epsclosure P((_position_set *s, struct regexp *r));
+static void build_state P((int s, struct regexp *r));
+static void build_state_zero P((struct regexp *r));
+static char *icatalloc P((char *old, const char *new));
+static char *icpyalloc P((const char *string));
+static char *istrstr P((char *lookin, char *lookfor));
+static void ifree P((char *cp));
+static void freelist P((char **cpp));
+static char **enlist P((char **cpp, char *new, size_t len));
+static char **comsubs P((char *left, char *right));
+static char **addlists P((char **old, char **new));
+static char **inboth P((char **left, char **right));
+static void resetmust P((must *mp));
+static void regmust P((struct regexp *r));
+
+#undef P
+
+static ptr_t
+xcalloc(n, s)
+     int n;
+     size_t s;
+{
+  ptr_t r = calloc(n, s);
+
+  if (NULL == r)
+    reg_error("Memory exhausted");  /* reg_error does not return */
+  return r;
+}
+
+static ptr_t
+xmalloc(n)
+     size_t n;
+{
+  ptr_t r = malloc(n);
+
+  assert(n != 0);
+  if (NULL == r)
+    reg_error("Memory exhausted");
+  return r;
+}
+
+static ptr_t
+xrealloc(p, n)
+     ptr_t p;
+     size_t n;
+{
+  ptr_t r = realloc(p, n);
+
+  assert(n != 0);
+  if (NULL == r)
+    reg_error("Memory exhausted");
+  return r;
+}
+
+#define CALLOC(p, t, n) ((p) = (t *) xcalloc((n), sizeof (t)))
+#undef MALLOC
+#define MALLOC(p, t, n) ((p) = (t *) xmalloc((n) * sizeof (t)))
+#define REALLOC(p, t, n) ((p) = (t *) xrealloc((ptr_t) (p), (n) * sizeof (t)))
+
+/* Reallocate an array of type t if nalloc is too small for index. */
+#define REALLOC_IF_NECESSARY(p, t, nalloc, index) \
+  if ((index) >= (nalloc))			  \
+    {						  \
+      while ((index) >= (nalloc))		  \
+	(nalloc) *= 2;				  \
+      REALLOC(p, t, nalloc);			  \
+    }
+
+/* Stuff pertaining to charsets. */
+
+static int
+tstbit(b, c)
+     int b;
+     _charset c;
+{
+  return c[b / INTBITS] & 1 << b % INTBITS;
+}
+
+static void
+setbit(b, c)
+     int b;
+     _charset c;
+{
+  c[b / INTBITS] |= 1 << b % INTBITS;
+}
+
+static void
+clrbit(b, c)
+     int b;
+     _charset c;
+{
+  c[b / INTBITS] &= ~(1 << b % INTBITS);
+}
+
+static void
+copyset(src, dst)
+     const _charset src;
+     _charset dst;
+{
+  int i;
+
+  for (i = 0; i < _CHARSET_INTS; ++i)
+    dst[i] = src[i];
+}
+
+static void
+zeroset(s)
+     _charset s;
+{
+  int i;
+
+  for (i = 0; i < _CHARSET_INTS; ++i)
+    s[i] = 0;
+}
+
+static void
+notset(s)
+     _charset s;
+{
+  int i;
+
+  for (i = 0; i < _CHARSET_INTS; ++i)
+    s[i] = ~s[i];
+}
+
+static int
+equal(s1, s2)
+     const _charset s1;
+     const _charset s2;
+{
+  int i;
+
+  for (i = 0; i < _CHARSET_INTS; ++i)
+    if (s1[i] != s2[i])
+      return 0;
+  return 1;
+}
+
+/* A pointer to the current regexp is kept here during parsing. */
+static struct regexp *reg;
+
+/* Find the index of charset s in reg->charsets, or allocate a new charset. */
+static int
+charset_index(s)
+     const _charset s;
+{
+  int i;
+
+  for (i = 0; i < reg->cindex; ++i)
+    if (equal(s, reg->charsets[i]))
+      return i;
+  REALLOC_IF_NECESSARY(reg->charsets, _charset, reg->calloc, reg->cindex);
+  ++reg->cindex;
+  copyset(s, reg->charsets[i]);
+  return i;
+}
+
+/* Syntax bits controlling the behavior of the lexical analyzer. */
+static syntax_bits, syntax_bits_set;
+
+/* Flag for case-folding letters into sets. */
+static case_fold;
+
+/* Entry point to set syntax options. */
+void
+regsyntax(bits, fold)
+     long bits;
+     int fold;
+{
+  syntax_bits_set = 1;
+  syntax_bits = bits;
+  case_fold = fold;
+}
+
+/* Lexical analyzer. */
+static const char *lexstart;	/* Pointer to beginning of input string. */
+static const char *lexptr;	/* Pointer to next input character. */
+static lexleft;			/* Number of characters remaining. */
+static caret_allowed;		/* True if backward context allows ^
+				   (meaningful only if RE_CONTEXT_INDEP_OPS
+				   is turned off). */
+static closure_allowed;		/* True if backward context allows closures
+				   (meaningful only if RE_CONTEXT_INDEP_OPS
+				   is turned off). */
+
+/* Note that characters become unsigned here. */
+#define FETCH(c, eoferr)   	      \
+  {			   	      \
+    if (! lexleft)	   	      \
+      if (eoferr != NULL)   	      \
+	reg_error(eoferr);  	      \
+      else		   	      \
+	return _END;	   	      \
+    (c) = (unsigned char) *lexptr++;  \
+    --lexleft;		   	      \
+  }
+
+static _token
+lex()
+{
+  _token c, c2;
+  int invert;
+  _charset cset;
+
+  FETCH(c, (char *) 0);
+  switch (c)
+    {
+    case '^':
+      if (! (syntax_bits & RE_CONTEXT_INDEP_OPS)
+	  && (!caret_allowed ||
+	      ((syntax_bits & RE_TIGHT_VBAR) && lexptr - 1 != lexstart)))
+	goto normal_char;
+      caret_allowed = 0;
+      return syntax_bits & RE_TIGHT_VBAR ? _ALLBEGLINE : _BEGLINE;
+
+    case '$':
+      if (syntax_bits & RE_CONTEXT_INDEP_OPS || !lexleft
+	  || (! (syntax_bits & RE_TIGHT_VBAR)
+	      && ((syntax_bits & RE_NO_BK_PARENS
+		   ? lexleft > 0 && *lexptr == ')'
+		   : lexleft > 1 && *lexptr == '\\' && lexptr[1] == ')')
+		  || (syntax_bits & RE_NO_BK_VBAR
+		      ? lexleft > 0 && *lexptr == '|'
+		      : lexleft > 1 && *lexptr == '\\' && lexptr[1] == '|'))))
+	return syntax_bits & RE_TIGHT_VBAR ? _ALLENDLINE : _ENDLINE;
+      goto normal_char;
+
+    case '\\':
+      FETCH(c, "Unfinished \\ quote");
+      switch (c)
+	{
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+	  caret_allowed = 0;
+	  closure_allowed = 1;
+	  return _BACKREF;
+
+	case '<':
+	  caret_allowed = 0;
+	  return _BEGWORD;
+
+	case '>':
+	  caret_allowed = 0;
+	  return _ENDWORD;
+
+	case 'b':
+	  caret_allowed = 0;
+	  return _LIMWORD;
+
+	case 'B':
+	  caret_allowed = 0;
+	  return _NOTLIMWORD;
+
+	case 'w':
+	case 'W':
+	  zeroset(cset);
+	  for (c2 = 0; c2 < _NOTCHAR; ++c2)
+	    if (ISALNUM(c2))
+	      setbit(c2, cset);
+	  if (c == 'W')
+	    notset(cset);
+	  caret_allowed = 0;
+	  closure_allowed = 1;
+	  return _SET + charset_index(cset);
+
+	case '?':
+	  if (syntax_bits & RE_BK_PLUS_QM)
+	    goto qmark;
+	  goto normal_char;
+
+	case '+':
+	  if (syntax_bits & RE_BK_PLUS_QM)
+	    goto plus;
+	  goto normal_char;
+
+	case '|':
+	  if (! (syntax_bits & RE_NO_BK_VBAR))
+	    goto or;
+	  goto normal_char;
+
+	case '(':
+	  if (! (syntax_bits & RE_NO_BK_PARENS))
+	    goto lparen;
+	  goto normal_char;
+
+	case ')':
+	  if (! (syntax_bits & RE_NO_BK_PARENS))
+	    goto rparen;
+	  goto normal_char;
+
+	default:
+	  goto normal_char;
+	}
+
+    case '?':
+      if (syntax_bits & RE_BK_PLUS_QM)
+	goto normal_char;
+    qmark:
+      if (! (syntax_bits & RE_CONTEXT_INDEP_OPS) && !closure_allowed)
+	goto normal_char;
+      return _QMARK;
+
+    case '*':
+      if (! (syntax_bits & RE_CONTEXT_INDEP_OPS) && !closure_allowed)
+	goto normal_char;
+      return _STAR;
+
+    case '+':
+      if (syntax_bits & RE_BK_PLUS_QM)
+	goto normal_char;
+    plus:
+      if (! (syntax_bits & RE_CONTEXT_INDEP_OPS) && !closure_allowed)
+	goto normal_char;
+      return _PLUS;
+
+    case '|':
+      if (! (syntax_bits & RE_NO_BK_VBAR))
+	goto normal_char;
+    or:
+      caret_allowed = 1;
+      closure_allowed = 0;
+      return _OR;
+
+    case '\n':
+      if (! (syntax_bits & RE_NEWLINE_OR))
+	goto normal_char;
+      goto or;
+
+    case '(':
+      if (! (syntax_bits & RE_NO_BK_PARENS))
+	goto normal_char;
+    lparen:
+      caret_allowed = 1;
+      closure_allowed = 0;
+      return _LPAREN;
+
+    case ')':
+      if (! (syntax_bits & RE_NO_BK_PARENS))
+	goto normal_char;
+    rparen:
+      caret_allowed = 0;
+      closure_allowed = 1;
+      return _RPAREN;
+
+    case '.':
+      zeroset(cset);
+      notset(cset);
+      clrbit('\n', cset);
+      caret_allowed = 0;
+      closure_allowed = 1;
+      return _SET + charset_index(cset);
+
+    case '[':
+      zeroset(cset);
+      FETCH(c, "Unbalanced [");
+      if (c == '^')
+	{
+	  FETCH(c, "Unbalanced [");
+	  invert = 1;
+	}
+      else
+	invert = 0;
+      do
+	{
+	  FETCH(c2, "Unbalanced [");
+	  if ((syntax_bits & RE_AWK_CLASS_HACK) && c == '\\')
+	    {
+	      c = c2;
+	      FETCH(c2, "Unbalanced [");
+	    }
+	  if (c2 == '-')
+	    {
+	      FETCH(c2, "Unbalanced [");
+	      if (c2 == ']' && (syntax_bits & RE_AWK_CLASS_HACK))
+		{
+		  setbit(c, cset);
+		  setbit('-', cset);
+		  break;
+	        }
+	      while (c <= c2)
+		  setbit(c++, cset);
+	      FETCH(c, "Unbalanced [");
+	    }
+	  else
+	    {
+	      setbit(c, cset);
+	      c = c2;
+	    }
+	}
+      while (c != ']');
+      if (invert)
+	notset(cset);
+      caret_allowed = 0;
+      closure_allowed = 1;
+      return _SET + charset_index(cset);
+
+    default:
+    normal_char:
+      caret_allowed = 0;
+      closure_allowed = 1;
+      if (case_fold && ISALPHA(c))
+	{
+	  zeroset(cset);
+	  if (isupper(c))
+	    c = tolower(c);
+	  setbit(c, cset);
+	  setbit(toupper(c), cset);
+	  return _SET + charset_index(cset);
+	}
+      return c;
+    }
+}
+
+/* Recursive descent parser for regular expressions. */
+
+static _token tok;		/* Lookahead token. */
+static depth;			/* Current depth of a hypothetical stack
+				   holding deferred productions.  This is
+				   used to determine the depth that will be
+				   required of the real stack later on in
+				   reganalyze(). */
+
+/* Add the given token to the parse tree, maintaining the depth count and
+   updating the maximum depth if necessary. */
+static void
+addtok(t)
+     _token t;
+{
+  REALLOC_IF_NECESSARY(reg->tokens, _token, reg->talloc, reg->tindex);
+  reg->tokens[reg->tindex++] = t;
+
+  switch (t)
+    {
+    case _QMARK:
+    case _STAR:
+    case _PLUS:
+      break;
+
+    case _CAT:
+    case _OR:
+      --depth;
+      break;
+
+    default:
+      ++reg->nleaves;
+    case _EMPTY:
+      ++depth;
+      break;
+    }
+  if (depth > reg->depth)
+    reg->depth = depth;
+}
+
+/* The grammar understood by the parser is as follows.
+
+   start:
+     regexp
+     _ALLBEGLINE regexp
+     regexp _ALLENDLINE
+     _ALLBEGLINE regexp _ALLENDLINE
+
+   regexp:
+     regexp _OR branch
+     branch
+
+   branch:
+     branch closure
+     closure
+
+   closure:
+     closure _QMARK
+     closure _STAR
+     closure _PLUS
+     atom
+
+   atom:
+     <normal character>
+     _SET
+     _BACKREF
+     _BEGLINE
+     _ENDLINE
+     _BEGWORD
+     _ENDWORD
+     _LIMWORD
+     _NOTLIMWORD
+     <empty>
+
+   The parser builds a parse tree in postfix form in an array of tokens. */
+
+#ifdef __STDC__
+static void regexp(void);
+#else
+static void regexp();
+#endif
+
+static void
+atom()
+{
+  if (tok >= 0 && (tok < _NOTCHAR || tok >= _SET || tok == _BACKREF
+      || tok == _BEGLINE || tok == _ENDLINE || tok == _BEGWORD
+      || tok == _ENDWORD || tok == _LIMWORD || tok == _NOTLIMWORD))
+    {
+      addtok(tok);
+      tok = lex();
+    }
+  else if (tok == _LPAREN)
+    {
+      tok = lex();
+      regexp();
+      if (tok != _RPAREN)
+	reg_error("Unbalanced (");
+      tok = lex();
+    }
+  else
+    addtok(_EMPTY);
+}
+
+static void
+closure()
+{
+  atom();
+  while (tok == _QMARK || tok == _STAR || tok == _PLUS)
+    {
+      addtok(tok);
+      tok = lex();
+    }
+}
+
+static void
+branch()
+{
+  closure();
+  while (tok != _RPAREN && tok != _OR && tok != _ALLENDLINE && tok >= 0)
+    {
+      closure();
+      addtok(_CAT);
+    }
+}
+
+static void
+regexp()
+{
+  branch();
+  while (tok == _OR)
+    {
+      tok = lex();
+      branch();
+      addtok(_OR);
+    }
+}
+
+/* Main entry point for the parser.  S is a string to be parsed, len is the
+   length of the string, so s can include NUL characters.  R is a pointer to
+   the struct regexp to parse into. */
+void
+regparse(s, len, r)
+     const char *s;
+     size_t len;
+     struct regexp *r;
+{
+  reg = r;
+  lexstart = lexptr = s;
+  lexleft = len;
+  caret_allowed = 1;
+  closure_allowed = 0;
+
+  if (! syntax_bits_set)
+    reg_error("No syntax specified");
+
+  tok = lex();
+  depth = r->depth;
+
+  if (tok == _ALLBEGLINE)
+    {
+      addtok(_BEGLINE);
+      tok = lex();
+      regexp();
+      addtok(_CAT);
+    }
+  else
+    regexp();
+
+  if (tok == _ALLENDLINE)
+    {
+      addtok(_ENDLINE);
+      addtok(_CAT);
+      tok = lex();
+    }
+
+  if (tok != _END)
+    reg_error("Unbalanced )");
+
+  addtok(_END - r->nregexps);
+  addtok(_CAT);
+
+  if (r->nregexps)
+    addtok(_OR);
+
+  ++r->nregexps;
+}
+
+/* Some primitives for operating on sets of positions. */
+
+/* Copy one set to another; the destination must be large enough. */
+static void
+copy(src, dst)
+     const _position_set *src;
+     _position_set *dst;
+{
+  int i;
+
+  for (i = 0; i < src->nelem; ++i)
+    dst->elems[i] = src->elems[i];
+  dst->nelem = src->nelem;
+}
+
+/* Insert a position in a set.  Position sets are maintained in sorted
+   order according to index.  If position already exists in the set with
+   the same index then their constraints are logically or'd together.
+   S->elems must point to an array large enough to hold the resulting set. */
+static void
+insert(p, s)
+     _position p;
+     _position_set *s;
+{
+  int i;
+  _position t1, t2;
+
+  for (i = 0; i < s->nelem && p.index < s->elems[i].index; ++i)
+    ;
+  if (i < s->nelem && p.index == s->elems[i].index)
+    s->elems[i].constraint |= p.constraint;
+  else
+    {
+      t1 = p;
+      ++s->nelem;
+      while (i < s->nelem)
+	{
+	  t2 = s->elems[i];
+	  s->elems[i++] = t1;
+	  t1 = t2;
+	}
+    }
+}
+
+/* Merge two sets of positions into a third.  The result is exactly as if
+   the positions of both sets were inserted into an initially empty set. */
+static void
+merge(s1, s2, m)
+     _position_set *s1;
+     _position_set *s2;
+     _position_set *m;
+{
+  int i = 0, j = 0;
+
+  m->nelem = 0;
+  while (i < s1->nelem && j < s2->nelem)
+    if (s1->elems[i].index > s2->elems[j].index)
+      m->elems[m->nelem++] = s1->elems[i++];
+    else if (s1->elems[i].index < s2->elems[j].index)
+      m->elems[m->nelem++] = s2->elems[j++];
+    else
+      {
+	m->elems[m->nelem] = s1->elems[i++];
+	m->elems[m->nelem++].constraint |= s2->elems[j++].constraint;
+      }
+  while (i < s1->nelem)
+    m->elems[m->nelem++] = s1->elems[i++];
+  while (j < s2->nelem)
+    m->elems[m->nelem++] = s2->elems[j++];
+}
+
+/* Delete a position from a set. */
+static void
+delete(p, s)
+     _position p;
+     _position_set *s;
+{
+  int i;
+
+  for (i = 0; i < s->nelem; ++i)
+    if (p.index == s->elems[i].index)
+      break;
+  if (i < s->nelem)
+    for (--s->nelem; i < s->nelem; ++i)
+      s->elems[i] = s->elems[i + 1];
+}
+
+/* Find the index of the state corresponding to the given position set with
+   the given preceding context, or create a new state if there is no such
+   state.  Newline and letter tell whether we got here on a newline or
+   letter, respectively. */
+static int
+state_index(r, s, newline, letter)
+     struct regexp *r;
+     _position_set *s;
+     int newline;
+     int letter;
+{
+  int lhash = 0;
+  int constraint;
+  int i, j;
+
+  newline = newline ? 1 : 0;
+  letter = letter ? 1 : 0;
+
+  for (i = 0; i < s->nelem; ++i)
+    lhash ^= s->elems[i].index + s->elems[i].constraint;
+
+  /* Try to find a state that exactly matches the proposed one. */
+  for (i = 0; i < r->sindex; ++i)
+    {
+      if (lhash != r->states[i].hash || s->nelem != r->states[i].elems.nelem
+	  || newline != r->states[i].newline || letter != r->states[i].letter)
+	continue;
+      for (j = 0; j < s->nelem; ++j)
+	if (s->elems[j].constraint
+	    != r->states[i].elems.elems[j].constraint
+	    || s->elems[j].index != r->states[i].elems.elems[j].index)
+	  break;
+      if (j == s->nelem)
+	return i;
+    }
+
+  /* We'll have to create a new state. */
+  REALLOC_IF_NECESSARY(r->states, _dfa_state, r->salloc, r->sindex);
+  r->states[i].hash = lhash;
+  MALLOC(r->states[i].elems.elems, _position, s->nelem);
+  copy(s, &r->states[i].elems);
+  r->states[i].newline = newline;
+  r->states[i].letter = letter;
+  r->states[i].backref = 0;
+  r->states[i].constraint = 0;
+  r->states[i].first_end = 0;
+  for (j = 0; j < s->nelem; ++j)
+    if (r->tokens[s->elems[j].index] < 0)
+      {
+	constraint = s->elems[j].constraint;
+	if (_SUCCEEDS_IN_CONTEXT(constraint, newline, 0, letter, 0)
+	    || _SUCCEEDS_IN_CONTEXT(constraint, newline, 0, letter, 1)
+	    || _SUCCEEDS_IN_CONTEXT(constraint, newline, 1, letter, 0)
+	    || _SUCCEEDS_IN_CONTEXT(constraint, newline, 1, letter, 1))
+	  r->states[i].constraint |= constraint;
+	if (! r->states[i].first_end)
+	  r->states[i].first_end = r->tokens[s->elems[j].index];
+      }
+    else if (r->tokens[s->elems[j].index] == _BACKREF)
+      {
+	r->states[i].constraint = _NO_CONSTRAINT;
+	r->states[i].backref = 1;
+      }
+
+  ++r->sindex;
+
+  return i;
+}
+
+/* Find the epsilon closure of a set of positions.  If any position of the set
+   contains a symbol that matches the empty string in some context, replace
+   that position with the elements of its follow labeled with an appropriate
+   constraint.  Repeat exhaustively until no funny positions are left.
+   S->elems must be large enough to hold the result. */
+static void
+epsclosure(s, r)
+     _position_set *s;
+     struct regexp *r;
+{
+  int i, j;
+  int *visited;
+  _position p, old;
+
+  MALLOC(visited, int, r->tindex);
+  for (i = 0; i < r->tindex; ++i)
+    visited[i] = 0;
+
+  for (i = 0; i < s->nelem; ++i)
+    if (r->tokens[s->elems[i].index] >= _NOTCHAR
+	&& r->tokens[s->elems[i].index] != _BACKREF
+	&& r->tokens[s->elems[i].index] < _SET)
+      {
+	old = s->elems[i];
+	p.constraint = old.constraint;
+	delete(s->elems[i], s);
+	if (visited[old.index])
+	  {
+	    --i;
+	    continue;
+	  }
+	visited[old.index] = 1;
+	switch (r->tokens[old.index])
+	  {
+	  case _BEGLINE:
+	    p.constraint &= _BEGLINE_CONSTRAINT;
+	    break;
+	  case _ENDLINE:
+	    p.constraint &= _ENDLINE_CONSTRAINT;
+	    break;
+	  case _BEGWORD:
+	    p.constraint &= _BEGWORD_CONSTRAINT;
+	    break;
+	  case _ENDWORD:
+	    p.constraint &= _ENDWORD_CONSTRAINT;
+	    break;
+	  case _LIMWORD:
+	    p.constraint &= _ENDWORD_CONSTRAINT;
+	    break;
+	  case _NOTLIMWORD:
+	    p.constraint &= _NOTLIMWORD_CONSTRAINT;
+	    break;
+	  default:
+	    break;
+	  }
+	for (j = 0; j < r->follows[old.index].nelem; ++j)
+	  {
+	    p.index = r->follows[old.index].elems[j].index;
+	    insert(p, s);
+	  }
+	/* Force rescan to start at the beginning. */
+	i = -1;
+      }
+
+  free(visited);
+}
+
+/* Perform bottom-up analysis on the parse tree, computing various functions.
+   Note that at this point, we're pretending constructs like \< are real
+   characters rather than constraints on what can follow them.
+
+   Nullable:  A node is nullable if it is at the root of a regexp that can
+   match the empty string.
+   *  _EMPTY leaves are nullable.
+   * No other leaf is nullable.
+   * A _QMARK or _STAR node is nullable.
+   * A _PLUS node is nullable if its argument is nullable.
+   * A _CAT node is nullable if both its arguments are nullable.
+   * An _OR node is nullable if either argument is nullable.
+
+   Firstpos:  The firstpos of a node is the set of positions (nonempty leaves)
+   that could correspond to the first character of a string matching the
+   regexp rooted at the given node.
+   * _EMPTY leaves have empty firstpos.
+   * The firstpos of a nonempty leaf is that leaf itself.
+   * The firstpos of a _QMARK, _STAR, or _PLUS node is the firstpos of its
+     argument.
+   * The firstpos of a _CAT node is the firstpos of the left argument, union
+     the firstpos of the right if the left argument is nullable.
+   * The firstpos of an _OR node is the union of firstpos of each argument.
+
+   Lastpos:  The lastpos of a node is the set of positions that could
+   correspond to the last character of a string matching the regexp at
+   the given node.
+   * _EMPTY leaves have empty lastpos.
+   * The lastpos of a nonempty leaf is that leaf itself.
+   * The lastpos of a _QMARK, _STAR, or _PLUS node is the lastpos of its
+     argument.
+   * The lastpos of a _CAT node is the lastpos of its right argument, union
+     the lastpos of the left if the right argument is nullable.
+   * The lastpos of an _OR node is the union of the lastpos of each argument.
+
+   Follow:  The follow of a position is the set of positions that could
+   correspond to the character following a character matching the node in
+   a string matching the regexp.  At this point we consider special symbols
+   that match the empty string in some context to be just normal characters.
+   Later, if we find that a special symbol is in a follow set, we will
+   replace it with the elements of its follow, labeled with an appropriate
+   constraint.
+   * Every node in the firstpos of the argument of a _STAR or _PLUS node is in
+     the follow of every node in the lastpos.
+   * Every node in the firstpos of the second argument of a _CAT node is in
+     the follow of every node in the lastpos of the first argument.
+
+   Because of the postfix representation of the parse tree, the depth-first
+   analysis is conveniently done by a linear scan with the aid of a stack.
+   Sets are stored as arrays of the elements, obeying a stack-like allocation
+   scheme; the number of elements in each set deeper in the stack can be
+   used to determine the address of a particular set's array. */
+void
+reganalyze(r, searchflag)
+     struct regexp *r;
+     int searchflag;
+{
+  int *nullable;		/* Nullable stack. */
+  int *nfirstpos;		/* Element count stack for firstpos sets. */
+  _position *firstpos;		/* Array where firstpos elements are stored. */
+  int *nlastpos;		/* Element count stack for lastpos sets. */
+  _position *lastpos;		/* Array where lastpos elements are stored. */
+  int *nalloc;			/* Sizes of arrays allocated to follow sets. */
+  _position_set tmp;		/* Temporary set for merging sets. */
+  _position_set merged;		/* Result of merging sets. */
+  int wants_newline;		/* True if some position wants newline info. */
+  int *o_nullable;
+  int *o_nfirst, *o_nlast;
+  _position *o_firstpos, *o_lastpos;
+  int i, j;
+  _position *pos;
+
+  r->searchflag = searchflag;
+
+  MALLOC(nullable, int, r->depth);
+  o_nullable = nullable;
+  MALLOC(nfirstpos, int, r->depth);
+  o_nfirst = nfirstpos;
+  MALLOC(firstpos, _position, r->nleaves);
+  o_firstpos = firstpos, firstpos += r->nleaves;
+  MALLOC(nlastpos, int, r->depth);
+  o_nlast = nlastpos;
+  MALLOC(lastpos, _position, r->nleaves);
+  o_lastpos = lastpos, lastpos += r->nleaves;
+  MALLOC(nalloc, int, r->tindex);
+  for (i = 0; i < r->tindex; ++i)
+    nalloc[i] = 0;
+  MALLOC(merged.elems, _position, r->nleaves);
+
+  CALLOC(r->follows, _position_set, r->tindex);
+
+  for (i = 0; i < r->tindex; ++i)
+    switch (r->tokens[i])
+      {
+      case _EMPTY:
+	/* The empty set is nullable. */
+	*nullable++ = 1;
+
+	/* The firstpos and lastpos of the empty leaf are both empty. */
+	*nfirstpos++ = *nlastpos++ = 0;
+	break;
+
+      case _STAR:
+      case _PLUS:
+	/* Every element in the firstpos of the argument is in the follow
+	   of every element in the lastpos. */
+	tmp.nelem = nfirstpos[-1];
+	tmp.elems = firstpos;
+	pos = lastpos;
+	for (j = 0; j < nlastpos[-1]; ++j)
+	  {
+	    merge(&tmp, &r->follows[pos[j].index], &merged);
+	    REALLOC_IF_NECESSARY(r->follows[pos[j].index].elems, _position,
+				 nalloc[pos[j].index], merged.nelem - 1);
+	    copy(&merged, &r->follows[pos[j].index]);
+	  }
+
+      case _QMARK:
+	/* A _QMARK or _STAR node is automatically nullable. */
+	if (r->tokens[i] != _PLUS)
+	  nullable[-1] = 1;
+	break;
+
+      case _CAT:
+	/* Every element in the firstpos of the second argument is in the
+	   follow of every element in the lastpos of the first argument. */
+	tmp.nelem = nfirstpos[-1];
+	tmp.elems = firstpos;
+	pos = lastpos + nlastpos[-1];
+	for (j = 0; j < nlastpos[-2]; ++j)
+	  {
+	    merge(&tmp, &r->follows[pos[j].index], &merged);
+	    REALLOC_IF_NECESSARY(r->follows[pos[j].index].elems, _position,
+				 nalloc[pos[j].index], merged.nelem - 1);
+	    copy(&merged, &r->follows[pos[j].index]);
+	  }
+
+	/* The firstpos of a _CAT node is the firstpos of the first argument,
+	   union that of the second argument if the first is nullable. */
+	if (nullable[-2])
+	  nfirstpos[-2] += nfirstpos[-1];
+	else
+	  firstpos += nfirstpos[-1];
+	--nfirstpos;
+
+	/* The lastpos of a _CAT node is the lastpos of the second argument,
+	   union that of the first argument if the second is nullable. */
+	if (nullable[-1])
+	  nlastpos[-2] += nlastpos[-1];
+	else
+	  {
+	    pos = lastpos + nlastpos[-2];
+	    for (j = nlastpos[-1] - 1; j >= 0; --j)
+	      pos[j] = lastpos[j];
+	    lastpos += nlastpos[-2];
+	    nlastpos[-2] = nlastpos[-1];
+	  }
+	--nlastpos;
+
+	/* A _CAT node is nullable if both arguments are nullable. */
+	nullable[-2] = nullable[-1] && nullable[-2];
+	--nullable;
+	break;
+
+      case _OR:
+	/* The firstpos is the union of the firstpos of each argument. */
+	nfirstpos[-2] += nfirstpos[-1];
+	--nfirstpos;
+
+	/* The lastpos is the union of the lastpos of each argument. */
+	nlastpos[-2] += nlastpos[-1];
+	--nlastpos;
+
+	/* An _OR node is nullable if either argument is nullable. */
+	nullable[-2] = nullable[-1] || nullable[-2];
+	--nullable;
+	break;
+
+      default:
+	/* Anything else is a nonempty position.  (Note that special
+	   constructs like \< are treated as nonempty strings here;
+	   an "epsilon closure" effectively makes them nullable later.
+	   Backreferences have to get a real position so we can detect
+	   transitions on them later.  But they are nullable. */
+	*nullable++ = r->tokens[i] == _BACKREF;
+
+	/* This position is in its own firstpos and lastpos. */
+	*nfirstpos++ = *nlastpos++ = 1;
+	--firstpos, --lastpos;
+	firstpos->index = lastpos->index = i;
+	firstpos->constraint = lastpos->constraint = _NO_CONSTRAINT;
+
+	/* Allocate the follow set for this position. */
+	nalloc[i] = 1;
+	MALLOC(r->follows[i].elems, _position, nalloc[i]);
+	break;
+      }
+
+  /* For each follow set that is the follow set of a real position, replace
+     it with its epsilon closure. */
+  for (i = 0; i < r->tindex; ++i)
+    if (r->tokens[i] < _NOTCHAR || r->tokens[i] == _BACKREF
+	|| r->tokens[i] >= _SET)
+      {
+	copy(&r->follows[i], &merged);
+	epsclosure(&merged, r);
+	if (r->follows[i].nelem < merged.nelem)
+	  REALLOC(r->follows[i].elems, _position, merged.nelem);
+	copy(&merged, &r->follows[i]);
+      }
+
+  /* Get the epsilon closure of the firstpos of the regexp.  The result will
+     be the set of positions of state 0. */
+  merged.nelem = 0;
+  for (i = 0; i < nfirstpos[-1]; ++i)
+    insert(firstpos[i], &merged);
+  epsclosure(&merged, r);
+
+  /* Check if any of the positions of state 0 will want newline context. */
+  wants_newline = 0;
+  for (i = 0; i < merged.nelem; ++i)
+    if (_PREV_NEWLINE_DEPENDENT(merged.elems[i].constraint))
+      wants_newline = 1;
+
+  /* Build the initial state. */
+  r->salloc = 1;
+  r->sindex = 0;
+  MALLOC(r->states, _dfa_state, r->salloc);
+  state_index(r, &merged, wants_newline, 0);
+
+  free(o_nullable);
+  free(o_nfirst);
+  free(o_firstpos);
+  free(o_nlast);
+  free(o_lastpos);
+  free(nalloc);
+  free(merged.elems);
+}
+
+/* Find, for each character, the transition out of state s of r, and store
+   it in the appropriate slot of trans.
+
+   We divide the positions of s into groups (positions can appear in more
+   than one group).  Each group is labeled with a set of characters that
+   every position in the group matches (taking into account, if necessary,
+   preceding context information of s).  For each group, find the union
+   of the its elements' follows.  This set is the set of positions of the
+   new state.  For each character in the group's label, set the transition
+   on this character to be to a state corresponding to the set's positions,
+   and its associated backward context information, if necessary.
+
+   If we are building a searching matcher, we include the positions of state
+   0 in every state.
+
+   The collection of groups is constructed by building an equivalence-class
+   partition of the positions of s.
+
+   For each position, find the set of characters C that it matches.  Eliminate
+   any characters from C that fail on grounds of backward context.
+
+   Search through the groups, looking for a group whose label L has nonempty
+   intersection with C.  If L - C is nonempty, create a new group labeled
+   L - C and having the same positions as the current group, and set L to
+   the intersection of L and C.  Insert the position in this group, set
+   C = C - L, and resume scanning.
+
+   If after comparing with every group there are characters remaining in C,
+   create a new group labeled with the characters of C and insert this
+   position in that group. */
+void
+regstate(s, r, trans)
+     int s;
+     struct regexp *r;
+     int trans[];
+{
+  _position_set grps[_NOTCHAR];	/* As many as will ever be needed. */
+  _charset labels[_NOTCHAR];	/* Labels corresponding to the groups. */
+  int ngrps = 0;		/* Number of groups actually used. */
+  _position pos;		/* Current position being considered. */
+  _charset matches;		/* Set of matching characters. */
+  int matchesf;			/* True if matches is nonempty. */
+  _charset intersect;		/* Intersection with some label set. */
+  int intersectf;		/* True if intersect is nonempty. */
+  _charset leftovers;		/* Stuff in the label that didn't match. */
+  int leftoversf;		/* True if leftovers is nonempty. */
+  static _charset letters;	/* Set of characters considered letters. */
+  static _charset newline;	/* Set of characters that aren't newline. */
+  _position_set follows;	/* Union of the follows of some group. */
+  _position_set tmp;		/* Temporary space for merging sets. */
+  int state;			/* New state. */
+  int wants_newline;		/* New state wants to know newline context. */
+  int state_newline;		/* New state on a newline transition. */
+  int wants_letter;		/* New state wants to know letter context. */
+  int state_letter;		/* New state on a letter transition. */
+  static initialized;		/* Flag for static initialization. */
+  int i, j, k;
+
+  /* Initialize the set of letters, if necessary. */
+  if (! initialized)
+    {
+      initialized = 1;
+      for (i = 0; i < _NOTCHAR; ++i)
+	if (ISALNUM(i))
+	  setbit(i, letters);
+      setbit('\n', newline);
+    }
+
+  zeroset(matches);
+
+  for (i = 0; i < r->states[s].elems.nelem; ++i)
+    {
+      pos = r->states[s].elems.elems[i];
+      if (r->tokens[pos.index] >= 0 && r->tokens[pos.index] < _NOTCHAR)
+	setbit(r->tokens[pos.index], matches);
+      else if (r->tokens[pos.index] >= _SET)
+	copyset(r->charsets[r->tokens[pos.index] - _SET], matches);
+      else
+	continue;
+
+      /* Some characters may need to be climinated from matches because
+	 they fail in the current context. */
+      if (pos.constraint != 0xff)
+	{
+	  if (! _MATCHES_NEWLINE_CONTEXT(pos.constraint,
+					 r->states[s].newline, 1))
+	    clrbit('\n', matches);
+	  if (! _MATCHES_NEWLINE_CONTEXT(pos.constraint,
+					 r->states[s].newline, 0))
+	    for (j = 0; j < _CHARSET_INTS; ++j)
+	      matches[j] &= newline[j];
+	  if (! _MATCHES_LETTER_CONTEXT(pos.constraint,
+					r->states[s].letter, 1))
+	    for (j = 0; j < _CHARSET_INTS; ++j)
+	      matches[j] &= ~letters[j];
+	  if (! _MATCHES_LETTER_CONTEXT(pos.constraint,
+					r->states[s].letter, 0))
+	    for (j = 0; j < _CHARSET_INTS; ++j)
+	      matches[j] &= letters[j];
+
+	  /* If there are no characters left, there's no point in going on. */
+	  for (j = 0; j < _CHARSET_INTS && !matches[j]; ++j)
+	    ;
+	  if (j == _CHARSET_INTS)
+	    continue;
+	}
+
+      for (j = 0; j < ngrps; ++j)
+	{
+	  /* If matches contains a single character only, and the current
+	     group's label doesn't contain that character, go on to the
+	     next group. */
+	  if (r->tokens[pos.index] >= 0 && r->tokens[pos.index] < _NOTCHAR
+	      && !tstbit(r->tokens[pos.index], labels[j]))
+	    continue;
+
+	  /* Check if this group's label has a nonempty intersection with
+	     matches. */
+	  intersectf = 0;
+	  for (k = 0; k < _CHARSET_INTS; ++k)
+	    (intersect[k] = matches[k] & labels[j][k]) ? intersectf = 1 : 0;
+	  if (! intersectf)
+	    continue;
+
+	  /* It does; now find the set differences both ways. */
+	  leftoversf = matchesf = 0;
+	  for (k = 0; k < _CHARSET_INTS; ++k)
+	    {
+	      /* Even an optimizing compiler can't know this for sure. */
+	      int match = matches[k], label = labels[j][k];
+
+	      (leftovers[k] = ~match & label) ? leftoversf = 1 : 0;
+	      (matches[k] = match & ~label) ? matchesf = 1 : 0;
+	    }
+
+	  /* If there were leftovers, create a new group labeled with them. */
+	  if (leftoversf)
+	    {
+	      copyset(leftovers, labels[ngrps]);
+	      copyset(intersect, labels[j]);
+	      MALLOC(grps[ngrps].elems, _position, r->nleaves);
+	      copy(&grps[j], &grps[ngrps]);
+	      ++ngrps;
+	    }
+
+	  /* Put the position in the current group.  Note that there is no
+	     reason to call insert() here. */
+	  grps[j].elems[grps[j].nelem++] = pos;
+
+	  /* If every character matching the current position has been
+	     accounted for, we're done. */
+	  if (! matchesf)
+	    break;
+	}
+
+      /* If we've passed the last group, and there are still characters
+	 unaccounted for, then we'll have to create a new group. */
+      if (j == ngrps)
+	{
+	  copyset(matches, labels[ngrps]);
+	  zeroset(matches);
+	  MALLOC(grps[ngrps].elems, _position, r->nleaves);
+	  grps[ngrps].nelem = 1;
+	  grps[ngrps].elems[0] = pos;
+	  ++ngrps;
+	}
+    }
+
+  MALLOC(follows.elems, _position, r->nleaves);
+  MALLOC(tmp.elems, _position, r->nleaves);
+
+  /* If we are a searching matcher, the default transition is to a state
+     containing the positions of state 0, otherwise the default transition
+     is to fail miserably. */
+  if (r->searchflag)
+    {
+      wants_newline = 0;
+      wants_letter = 0;
+      for (i = 0; i < r->states[0].elems.nelem; ++i)
+	{
+	  if (_PREV_NEWLINE_DEPENDENT(r->states[0].elems.elems[i].constraint))
+	    wants_newline = 1;
+	  if (_PREV_LETTER_DEPENDENT(r->states[0].elems.elems[i].constraint))
+	    wants_letter = 1;
+	}
+      copy(&r->states[0].elems, &follows);
+      state = state_index(r, &follows, 0, 0);
+      if (wants_newline)
+	state_newline = state_index(r, &follows, 1, 0);
+      else
+	state_newline = state;
+      if (wants_letter)
+	state_letter = state_index(r, &follows, 0, 1);
+      else
+	state_letter = state;
+      for (i = 0; i < _NOTCHAR; ++i)
+	trans[i] = (ISALNUM(i)) ? state_letter : state ;
+      trans['\n'] = state_newline;
+    }
+  else
+    for (i = 0; i < _NOTCHAR; ++i)
+      trans[i] = -1;
+
+  for (i = 0; i < ngrps; ++i)
+    {
+      follows.nelem = 0;
+
+      /* Find the union of the follows of the positions of the group.
+	 This is a hideously inefficient loop.  Fix it someday. */
+      for (j = 0; j < grps[i].nelem; ++j)
+	for (k = 0; k < r->follows[grps[i].elems[j].index].nelem; ++k)
+	  insert(r->follows[grps[i].elems[j].index].elems[k], &follows);
+
+      /* If we are building a searching matcher, throw in the positions
+	 of state 0 as well. */
+      if (r->searchflag)
+	for (j = 0; j < r->states[0].elems.nelem; ++j)
+	  insert(r->states[0].elems.elems[j], &follows);
+
+      /* Find out if the new state will want any context information. */
+      wants_newline = 0;
+      if (tstbit('\n', labels[i]))
+	for (j = 0; j < follows.nelem; ++j)
+	  if (_PREV_NEWLINE_DEPENDENT(follows.elems[j].constraint))
+	    wants_newline = 1;
+
+      wants_letter = 0;
+      for (j = 0; j < _CHARSET_INTS; ++j)
+	if (labels[i][j] & letters[j])
+	  break;
+      if (j < _CHARSET_INTS)
+	for (j = 0; j < follows.nelem; ++j)
+	  if (_PREV_LETTER_DEPENDENT(follows.elems[j].constraint))
+	    wants_letter = 1;
+
+      /* Find the state(s) corresponding to the union of the follows. */
+      state = state_index(r, &follows, 0, 0);
+      if (wants_newline)
+	state_newline = state_index(r, &follows, 1, 0);
+      else
+	state_newline = state;
+      if (wants_letter)
+	state_letter = state_index(r, &follows, 0, 1);
+      else
+	state_letter = state;
+
+      /* Set the transitions for each character in the current label. */
+      for (j = 0; j < _CHARSET_INTS; ++j)
+	for (k = 0; k < INTBITS; ++k)
+	  if (labels[i][j] & 1 << k)
+	    {
+	      int c = j * INTBITS + k;
+
+	      if (c == '\n')
+		trans[c] = state_newline;
+	      else if (ISALNUM(c))
+		trans[c] = state_letter;
+	      else if (c < _NOTCHAR)
+		trans[c] = state;
+	    }
+    }
+
+  for (i = 0; i < ngrps; ++i)
+    free(grps[i].elems);
+  free(follows.elems);
+  free(tmp.elems);
+}
+
+/* Some routines for manipulating a compiled regexp's transition tables.
+   Each state may or may not have a transition table; if it does, and it
+   is a non-accepting state, then r->trans[state] points to its table.
+   If it is an accepting state then r->fails[state] points to its table.
+   If it has no table at all, then r->trans[state] is NULL.
+   TODO: Improve this comment, get rid of the unnecessary redundancy. */
+
+static void
+build_state(s, r)
+     int s;
+     struct regexp *r;
+{
+  int *trans;			/* The new transition table. */
+  int i;
+
+  /* Set an upper limit on the number of transition tables that will ever
+     exist at once.  1024 is arbitrary.  The idea is that the frequently
+     used transition tables will be quickly rebuilt, whereas the ones that
+     were only needed once or twice will be cleared away. */
+  if (r->trcount >= 1024)
+    {
+      for (i = 0; i < r->tralloc; ++i)
+	if (r->trans[i])
+	  {
+	    free((ptr_t) r->trans[i]);
+	    r->trans[i] = NULL;
+	  }
+	else if (r->fails[i])
+	  {
+	    free((ptr_t) r->fails[i]);
+	    r->fails[i] = NULL;
+	  }
+      r->trcount = 0;
+    }
+
+  ++r->trcount;
+
+  /* Set up the success bits for this state. */
+  r->success[s] = 0;
+  if (ACCEPTS_IN_CONTEXT(r->states[s].newline, 1, r->states[s].letter, 0,
+      s, *r))
+    r->success[s] |= 4;
+  if (ACCEPTS_IN_CONTEXT(r->states[s].newline, 0, r->states[s].letter, 1,
+      s, *r))
+    r->success[s] |= 2;
+  if (ACCEPTS_IN_CONTEXT(r->states[s].newline, 0, r->states[s].letter, 0,
+      s, *r))
+    r->success[s] |= 1;
+
+  MALLOC(trans, int, _NOTCHAR);
+  regstate(s, r, trans);
+
+  /* Now go through the new transition table, and make sure that the trans
+     and fail arrays are allocated large enough to hold a pointer for the
+     largest state mentioned in the table. */
+  for (i = 0; i < _NOTCHAR; ++i)
+    if (trans[i] >= r->tralloc)
+      {
+	int oldalloc = r->tralloc;
+
+	while (trans[i] >= r->tralloc)
+	  r->tralloc *= 2;
+	REALLOC(r->realtrans, int *, r->tralloc + 1);
+	r->trans = r->realtrans + 1;
+	REALLOC(r->fails, int *, r->tralloc);
+	REALLOC(r->success, int, r->tralloc);
+	REALLOC(r->newlines, int, r->tralloc);
+	while (oldalloc < r->tralloc)
+	  {
+	    r->trans[oldalloc] = NULL;
+	    r->fails[oldalloc++] = NULL;
+	  }
+      }
+
+  /* Keep the newline transition in a special place so we can use it as
+     a sentinel. */
+  r->newlines[s] = trans['\n'];
+  trans['\n'] = -1;
+
+  if (ACCEPTING(s, *r))
+    r->fails[s] = trans;
+  else
+    r->trans[s] = trans;
+}
+
+static void
+build_state_zero(r)
+     struct regexp *r;
+{
+  r->tralloc = 1;
+  r->trcount = 0;
+  CALLOC(r->realtrans, int *, r->tralloc + 1);
+  r->trans = r->realtrans + 1;
+  CALLOC(r->fails, int *, r->tralloc);
+  MALLOC(r->success, int, r->tralloc);
+  MALLOC(r->newlines, int, r->tralloc);
+  build_state(0, r);
+}
+
+/* Search through a buffer looking for a match to the given struct regexp.
+   Find the first occurrence of a string matching the regexp in the buffer,
+   and the shortest possible version thereof.  Return a pointer to the first
+   character after the match, or NULL if none is found.  Begin points to
+   the beginning of the buffer, and end points to the first character after
+   its end.  We store a newline in *end to act as a sentinel, so end had
+   better point somewhere valid.  Newline is a flag indicating whether to
+   allow newlines to be in the matching string.  If count is non-
+   NULL it points to a place we're supposed to increment every time we
+   see a newline.  Finally, if backref is non-NULL it points to a place
+   where we're supposed to store a 1 if backreferencing happened and the
+   match needs to be verified by a backtracking matcher.  Otherwise
+   we store a 0 in *backref. */
+char *
+regexecute(r, begin, end, newline, count, backref)
+     struct regexp *r;
+     char *begin;
+     char *end;
+     int newline;
+     int *count;
+     int *backref;
+{
+  register s, s1, tmp;		/* Current state. */
+  register unsigned char *p;	/* Current input character. */
+  register **trans, *t;		/* Copy of r->trans so it can be optimized
+				   into a register. */
+  static sbit[_NOTCHAR];	/* Table for anding with r->success. */
+  static sbit_init;
+
+  if (! sbit_init)
+    {
+      int i;
+
+      sbit_init = 1;
+      for (i = 0; i < _NOTCHAR; ++i)
+	sbit[i] = (ISALNUM(i)) ? 2 : 1;
+      sbit['\n'] = 4;
+    }
+
+  if (! r->tralloc)
+    build_state_zero(r);
+
+  s = s1 = 0;
+  p = (unsigned char *) begin;
+  trans = r->trans;
+  *end = '\n';
+
+  for (;;)
+    {
+      while ((t = trans[s]) != 0) { /* hand-optimized loop */
+	s1 = t[*p++];
+        if ((t = trans[s1]) == 0) {
+           tmp = s ; s = s1 ; s1 = tmp ; /* swap */
+           break;
+        }
+	s = t[*p++];
+      }
+
+      if (s >= 0 && p <= (unsigned char *) end && r->fails[s])
+	{
+	  if (r->success[s] & sbit[*p])
+	    {
+	      if (backref)
+		*backref = (r->states[s].backref != 0);
+	      return (char *) p;
+	    }
+
+	  s1 = s;
+	  s = r->fails[s][*p++];
+	  continue;
+	}
+
+      /* If the previous character was a newline, count it. */
+      if (count && (char *) p <= end && p[-1] == '\n')
+	++*count;
+
+      /* Check if we've run off the end of the buffer. */
+      if ((char *) p >= end)
+	return NULL;
+
+      if (s >= 0)
+	{
+	  build_state(s, r);
+	  trans = r->trans;
+	  continue;
+	}
+
+      if (p[-1] == '\n' && newline)
+	{
+	  s = r->newlines[s1];
+	  continue;
+	}
+
+      s = 0;
+    }
+}
+
+/* Initialize the components of a regexp that the other routines don't
+   initialize for themselves. */
+void
+reginit(r)
+     struct regexp *r;
+{
+  r->calloc = 1;
+  MALLOC(r->charsets, _charset, r->calloc);
+  r->cindex = 0;
+
+  r->talloc = 1;
+  MALLOC(r->tokens, _token, r->talloc);
+  r->tindex = r->depth = r->nleaves = r->nregexps = 0;
+
+  r->searchflag = 0;
+  r->tralloc = 0;
+}
+
+/* Parse and analyze a single string of the given length. */
+void
+regcompile(s, len, r, searchflag)
+     const char *s;
+     size_t len;
+     struct regexp *r;
+     int searchflag;
+{
+  if (case_fold)	/* dummy folding in service of regmust() */
+    {
+      char *regcopy;
+      int i;
+
+      regcopy = malloc(len);
+      if (!regcopy)
+	reg_error("out of memory");
+      
+      /* This is a complete kludge and could potentially break
+	 \<letter> escapes . . . */
+      case_fold = 0;
+      for (i = 0; i < len; ++i)
+	if (ISUPPER(s[i]))
+	  regcopy[i] = tolower(s[i]);
+	else
+	  regcopy[i] = s[i];
+
+      reginit(r);
+      r->mustn = 0;
+      r->must[0] = '\0';
+      regparse(regcopy, len, r);
+      free(regcopy);
+      regmust(r);
+      reganalyze(r, searchflag);
+      case_fold = 1;
+      reginit(r);
+      regparse(s, len, r);
+      reganalyze(r, searchflag);
+    }
+  else
+    {
+        reginit(r);
+        regparse(s, len, r);
+        regmust(r);
+        reganalyze(r, searchflag);
+    }
+}
+
+/* Free the storage held by the components of a regexp. */
+void
+reg_free(r)
+     struct regexp *r;
+{
+  int i;
+
+  free((ptr_t) r->charsets);
+  free((ptr_t) r->tokens);
+  for (i = 0; i < r->sindex; ++i)
+    free((ptr_t) r->states[i].elems.elems);
+  free((ptr_t) r->states);
+  for (i = 0; i < r->tindex; ++i)
+    if (r->follows[i].elems)
+      free((ptr_t) r->follows[i].elems);
+  free((ptr_t) r->follows);
+  for (i = 0; i < r->tralloc; ++i)
+    if (r->trans[i])
+      free((ptr_t) r->trans[i]);
+    else if (r->fails[i])
+      free((ptr_t) r->fails[i]);
+  if (r->realtrans)
+    free((ptr_t) r->realtrans);
+  if (r->fails)
+    free((ptr_t) r->fails);
+  if (r->newlines)
+    free((ptr_t) r->newlines);
+}
+
+/*
+Having found the postfix representation of the regular expression,
+try to find a long sequence of characters that must appear in any line
+containing the r.e.
+Finding a "longest" sequence is beyond the scope here;
+we take an easy way out and hope for the best.
+(Take "(ab|a)b"--please.)
+
+We do a bottom-up calculation of sequences of characters that must appear
+in matches of r.e.'s represented by trees rooted at the nodes of the postfix
+representation:
+	sequences that must appear at the left of the match ("left")
+	sequences that must appear at the right of the match ("right")
+	lists of sequences that must appear somewhere in the match ("in")
+	sequences that must constitute the match ("is")
+When we get to the root of the tree, we use one of the longest of its
+calculated "in" sequences as our answer.  The sequence we find is returned in
+r->must (where "r" is the single argument passed to "regmust");
+the length of the sequence is returned in r->mustn.
+
+The sequences calculated for the various types of node (in pseudo ANSI c)
+are shown below.  "p" is the operand of unary operators (and the left-hand
+operand of binary operators); "q" is the right-hand operand of binary operators
+.
+"ZERO" means "a zero-length sequence" below.
+
+Type	left		right		is		in
+----	----		-----		--		--
+char c	# c		# c		# c		# c
+
+SET	ZERO		ZERO		ZERO		ZERO
+
+STAR	ZERO		ZERO		ZERO		ZERO
+
+QMARK	ZERO		ZERO		ZERO		ZERO
+
+PLUS	p->left		p->right	ZERO		p->in
+
+CAT	(p->is==ZERO)?	(q->is==ZERO)?	(p->is!=ZERO &&	p->in plus
+	p->left :	q->right :	q->is!=ZERO) ?	q->in plus
+	p->is##q->left	p->right##q->is	p->is##q->is :	p->right##q->left
+					ZERO
+
+OR	longest common	longest common	(do p->is and	substrings common to
+	leading		trailing	q->is have same	p->in and q->in
+	(sub)sequence	(sub)sequence	length and	
+	of p->left	of p->right	content) ?	
+	and q->left	and q->right	p->is : NULL	
+
+If there's anything else we recognize in the tree, all four sequences get set
+to zero-length sequences.  If there's something we don't recognize in the tree,
+we just return a zero-length sequence.
+
+Break ties in favor of infrequent letters (choosing 'zzz' in preference to
+'aaa')?
+
+And. . .is it here or someplace that we might ponder "optimizations" such as
+	egrep 'psi|epsilon'	->	egrep 'psi'
+	egrep 'pepsi|epsilon'	->	egrep 'epsi'
+					(Yes, we now find "epsi" as a "string
+					that must occur", but we might also
+					simplify the *entire* r.e. being sought
+)
+	grep '[c]'		->	grep 'c'
+	grep '(ab|a)b'		->	grep 'ab'
+	grep 'ab*'		->	grep 'a'
+	grep 'a*b'		->	grep 'b'
+There are several issues:
+	Is optimization easy (enough)?
+
+	Does optimization actually accomplish anything,
+	or is the automaton you get from "psi|epsilon" (for example)
+	the same as the one you get from "psi" (for example)?
+
+	Are optimizable r.e.'s likely to be used in real-life situations
+	(something like 'ab*' is probably unlikely; something like is
+	'psi|epsilon' is likelier)?
+*/
+
+static char *
+icatalloc(old, new)
+char *	old;
+const char *	new;
+{
+	register char *	result;
+	register int	oldsize, newsize;
+
+	newsize = (new == NULL) ? 0 : strlen(new);
+	if (old == NULL)
+		oldsize = 0;
+	else if (newsize == 0)
+		return old;
+	else	oldsize = strlen(old);
+	if (old == NULL)
+		result = (char *) malloc(newsize + 1);
+	else	result = (char *) realloc((void *) old, oldsize + newsize + 1);
+	if (result != NULL && new != NULL)
+		(void) strcpy(result + oldsize, new);
+	return result;
+}
+
+static char *
+icpyalloc(string)
+const char *	string;
+{
+	return icatalloc((char *) NULL, string);
+}
+
+static char *
+istrstr(lookin, lookfor)
+char *		lookin;
+register char *	lookfor;
+{
+	register char *	cp;
+	register int	len;
+
+	len = strlen(lookfor);
+	for (cp = lookin; *cp != '\0'; ++cp)
+		if (strncmp(cp, lookfor, len) == 0)
+			return cp;
+	return NULL;
+}
+
+static void
+ifree(cp)
+char *	cp;
+{
+	if (cp != NULL)
+		free(cp);
+}
+
+static void
+freelist(cpp)
+register char **	cpp;
+{
+	register int	i;
+
+	if (cpp == NULL)
+		return;
+	for (i = 0; cpp[i] != NULL; ++i) {
+		free(cpp[i]);
+		cpp[i] = NULL;
+	}
+}
+
+static char **
+enlist(cpp, new, len)
+register char **	cpp;
+register char *		new;
+#ifdef __STDC__
+size_t                  len;
+#else
+int                     len;
+#endif
+{
+	register int	i, j;
+
+	if (cpp == NULL)
+		return NULL;
+	if ((new = icpyalloc(new)) == NULL) {
+		freelist(cpp);
+		return NULL;
+	}
+	new[len] = '\0';
+	/*
+	** Is there already something in the list that's new (or longer)?
+	*/
+	for (i = 0; cpp[i] != NULL; ++i)
+		if (istrstr(cpp[i], new) != NULL) {
+			free(new);
+			return cpp;
+		}
+	/*
+	** Eliminate any obsoleted strings.
+	*/
+	j = 0;
+	while (cpp[j] != NULL)
+		if (istrstr(new, cpp[j]) == NULL)
+			++j;
+		else {
+			free(cpp[j]);
+			if (--i == j)
+				break;
+			cpp[j] = cpp[i];
+		}
+	/*
+	** Add the new string.
+	*/
+	cpp = (char **) realloc((char *) cpp, (i + 2) * sizeof *cpp);
+	if (cpp == NULL)
+		return NULL;
+	cpp[i] = new;
+	cpp[i + 1] = NULL;
+	return cpp;
+}
+
+/*
+** Given pointers to two strings,
+** return a pointer to an allocated list of their distinct common substrings.
+** Return NULL if something seems wild.
+*/
+
+static char **
+comsubs(left, right)
+char *	left;
+char *	right;
+{
+	register char **	cpp;
+	register char *		lcp;
+	register char *		rcp;
+	register int		i, len;
+
+	if (left == NULL || right == NULL)
+		return NULL;
+	cpp = (char **) malloc(sizeof *cpp);
+	if (cpp == NULL)
+		return NULL;
+	cpp[0] = NULL;
+	for (lcp = left; *lcp != '\0'; ++lcp) {
+		len = 0;
+		rcp = strchr(right, *lcp);
+		while (rcp != NULL) {
+			for (i = 1; lcp[i] != '\0' && lcp[i] == rcp[i]; ++i)
+				;
+			if (i > len)
+				len = i;
+			rcp = strchr(rcp + 1, *lcp);
+		}
+		if (len == 0)
+			continue;
+#ifdef __STDC__
+		if ((cpp = enlist(cpp, lcp, (size_t)len)) == NULL)
+#else
+		if ((cpp = enlist(cpp, lcp, len)) == NULL)
+#endif
+			break;
+	}
+	return cpp;
+}
+
+static char **
+addlists(old, new)
+char **	old;
+char **	new;
+{
+	register int	i;
+
+	if (old == NULL || new == NULL)
+		return NULL;
+	for (i = 0; new[i] != NULL; ++i) {
+		old = enlist(old, new[i], strlen(new[i]));
+		if (old == NULL)
+			break;
+	}
+	return old;
+}
+
+/*
+** Given two lists of substrings,
+** return a new list giving substrings common to both.
+*/
+
+static char **
+inboth(left, right)
+char **	left;
+char **	right;
+{
+	register char **	both;
+	register char **	temp;
+	register int		lnum, rnum;
+
+	if (left == NULL || right == NULL)
+		return NULL;
+	both = (char **) malloc(sizeof *both);
+	if (both == NULL)
+		return NULL;
+	both[0] = NULL;
+	for (lnum = 0; left[lnum] != NULL; ++lnum) {
+		for (rnum = 0; right[rnum] != NULL; ++rnum) {
+			temp = comsubs(left[lnum], right[rnum]);
+			if (temp == NULL) {
+				freelist(both);
+				return NULL;
+			}
+			both = addlists(both, temp);
+			freelist(temp);
+			if (both == NULL)
+				return NULL;
+		}
+	}
+	return both;
+}
+
+/*
+typedef struct {
+	char **	in;
+	char *	left;
+	char *	right;
+	char *	is;
+} must;
+ */
+static void
+resetmust(mp)
+register must *	mp;
+{
+	mp->left[0] = mp->right[0] = mp->is[0] = '\0';
+	freelist(mp->in);
+}
+
+static void
+regmust(r)
+register struct regexp *	r;
+{
+	register must *		musts;
+	register must *		mp;
+	register char *		result = "";
+	register int		ri;
+	register int		i;
+	register _token		t;
+	static must		must0;
+
+	reg->mustn = 0;
+	reg->must[0] = '\0';
+	musts = (must *) malloc((reg->tindex + 1) * sizeof *musts);
+	if (musts == NULL)
+		return;
+	mp = musts;
+	for (i = 0; i <= reg->tindex; ++i)
+		mp[i] = must0;
+	for (i = 0; i <= reg->tindex; ++i) {
+		mp[i].in = (char **) malloc(sizeof *mp[i].in);
+		mp[i].left = malloc(2);
+		mp[i].right = malloc(2);
+		mp[i].is = malloc(2);
+		if (mp[i].in == NULL || mp[i].left == NULL ||
+			mp[i].right == NULL || mp[i].is == NULL)
+				goto done;
+		mp[i].left[0] = mp[i].right[0] = mp[i].is[0] = '\0';
+		mp[i].in[0] = NULL;
+	}
+	for (ri = 0; ri < reg->tindex; ++ri) {
+		switch (t = reg->tokens[ri]) {
+		case _ALLBEGLINE:
+		case _ALLENDLINE:
+		case _LPAREN:
+		case _RPAREN:
+			goto done;		/* "cannot happen" */
+		case _EMPTY:
+		case _BEGLINE:
+		case _ENDLINE:
+		case _BEGWORD:
+		case _ENDWORD:
+		case _LIMWORD:
+		case _NOTLIMWORD:
+		case _BACKREF:
+			resetmust(mp);
+			break;
+		case _STAR:
+		case _QMARK:
+			if (mp <= musts)
+				goto done;	/* "cannot happen" */
+			--mp;
+			resetmust(mp);
+			break;
+		case _OR:
+			if (mp < &musts[2])
+				goto done;	/* "cannot happen" */
+			{
+				register char **	new;
+				register must *		lmp;
+				register must *		rmp;
+				register int		j, ln, rn, n;
+
+				rmp = --mp;
+				lmp = --mp;
+				/* Guaranteed to be.  Unlikely, but. . . */
+				if (strcmp(lmp->is, rmp->is) != 0)
+					lmp->is[0] = '\0';
+				/* Left side--easy */
+				i = 0;
+				while (lmp->left[i] != '\0' &&
+					lmp->left[i] == rmp->left[i])
+						++i;
+				lmp->left[i] = '\0';
+				/* Right side */
+				ln = strlen(lmp->right);
+				rn = strlen(rmp->right);
+				n = ln;
+				if (n > rn)
+					n = rn;
+				for (i = 0; i < n; ++i)
+					if (lmp->right[ln - i - 1] !=
+					    rmp->right[rn - i - 1])
+						break;
+				for (j = 0; j < i; ++j)
+					lmp->right[j] =
+						lmp->right[(ln - i) + j];
+				lmp->right[j] = '\0';
+				new = inboth(lmp->in, rmp->in);
+				if (new == NULL)
+					goto done;
+				freelist(lmp->in);
+				free((char *) lmp->in);
+				lmp->in = new;
+			}
+			break;
+		case _PLUS:
+			if (mp <= musts)
+				goto done;	/* "cannot happen" */
+			--mp;
+			mp->is[0] = '\0';
+			break;
+		case _END:
+			if (mp != &musts[1])
+				goto done;	/* "cannot happen" */
+			for (i = 0; musts[0].in[i] != NULL; ++i)
+				if (strlen(musts[0].in[i]) > strlen(result))
+					result = musts[0].in[i];
+			goto done;
+		case _CAT:
+			if (mp < &musts[2])
+				goto done;	/* "cannot happen" */
+			{
+				register must *	lmp;
+				register must *	rmp;
+
+				rmp = --mp;
+				lmp = --mp;
+				/*
+				** In.  Everything in left, plus everything in
+				** right, plus catenation of
+				** left's right and right's left.
+				*/
+				lmp->in = addlists(lmp->in, rmp->in);
+				if (lmp->in == NULL)
+					goto done;
+				if (lmp->right[0] != '\0' &&
+					rmp->left[0] != '\0') {
+						register char *	tp;
+
+						tp = icpyalloc(lmp->right);
+						if (tp == NULL)
+							goto done;
+						tp = icatalloc(tp, rmp->left);
+						if (tp == NULL)
+							goto done;
+						lmp->in = enlist(lmp->in, tp,
+							strlen(tp));
+						free(tp);
+						if (lmp->in == NULL)
+							goto done;
+				}
+				/* Left-hand */
+				if (lmp->is[0] != '\0') {
+					lmp->left = icatalloc(lmp->left,
+						rmp->left);
+					if (lmp->left == NULL)
+						goto done;
+				}
+				/* Right-hand */
+				if (rmp->is[0] == '\0')
+					lmp->right[0] = '\0';
+				lmp->right = icatalloc(lmp->right, rmp->right);
+				if (lmp->right == NULL)
+					goto done;
+				/* Guaranteed to be */
+				if (lmp->is[0] != '\0' && rmp->is[0] != '\0') {
+					lmp->is = icatalloc(lmp->is, rmp->is);
+					if (lmp->is == NULL)
+						goto done;
+				}
+			}
+			break;
+		default:
+			if (t < _END) {
+				/* "cannot happen" */
+				goto done;
+			} else if (t == '\0') {
+				/* not on *my* shift */
+				goto done;
+			} else if (t >= _SET) {
+				/* easy enough */
+				resetmust(mp);
+			} else {
+				/* plain character */
+				resetmust(mp);
+				mp->is[0] = mp->left[0] = mp->right[0] = t;
+				mp->is[1] = mp->left[1] = mp->right[1] = '\0';
+				mp->in = enlist(mp->in, mp->is, 1);
+				if (mp->in == NULL)
+					goto done;
+			}
+			break;
+		}
+		++mp;
+	}
+done:
+	(void) strncpy(reg->must, result, MUST_MAX - 1);
+	reg->must[MUST_MAX - 1] = '\0';
+	reg->mustn = strlen(reg->must);
+	mp = musts;
+	for (i = 0; i <= reg->tindex; ++i) {
+		freelist(mp[i].in);
+		ifree((char *) mp[i].in);
+		ifree(mp[i].left);
+		ifree(mp[i].right);
+		ifree(mp[i].is);
+	}
+	free((char *) mp);
+}
diff --git a/gnu/usr.bin/awk/dfa.h b/gnu/usr.bin/awk/dfa.h
new file mode 100644
index 000000000000..65fc49565a7c
--- /dev/null
+++ b/gnu/usr.bin/awk/dfa.h
@@ -0,0 +1,543 @@
+/* dfa.h - declarations for GNU deterministic regexp compiler
+   Copyright (C) 1988 Free Software Foundation, Inc.
+                      Written June, 1988 by Mike Haertel
+
+		       NO WARRANTY
+
+  BECAUSE THIS PROGRAM IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY
+NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW.  EXCEPT
+WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC,
+RICHARD M. STALLMAN AND/OR OTHER PARTIES PROVIDE THIS PROGRAM "AS IS"
+WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY
+AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE PROGRAM PROVE
+DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
+CORRECTION.
+
+ IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL RICHARD M.
+STALLMAN, THE FREE SOFTWARE FOUNDATION, INC., AND/OR ANY OTHER PARTY
+WHO MAY MODIFY AND REDISTRIBUTE THIS PROGRAM AS PERMITTED BELOW, BE
+LIABLE TO YOU FOR DAMAGES, INCLUDING ANY LOST PROFITS, LOST MONIES, OR
+OTHER SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR
+DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES OR
+A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) THIS
+PROGRAM, EVEN IF YOU HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
+DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY.
+
+		GENERAL PUBLIC LICENSE TO COPY
+
+  1. You may copy and distribute verbatim copies of this source file
+as you receive it, in any medium, provided that you conspicuously and
+appropriately publish on each copy a valid copyright notice "Copyright
+ (C) 1988 Free Software Foundation, Inc."; and include following the
+copyright notice a verbatim copy of the above disclaimer of warranty
+and of this License.  You may charge a distribution fee for the
+physical act of transferring a copy.
+
+  2. You may modify your copy or copies of this source file or
+any portion of it, and copy and distribute such modifications under
+the terms of Paragraph 1 above, provided that you also do the following:
+
+    a) cause the modified files to carry prominent notices stating
+    that you changed the files and the date of any change; and
+
+    b) cause the whole of any work that you distribute or publish,
+    that in whole or in part contains or is a derivative of this
+    program or any part thereof, to be licensed at no charge to all
+    third parties on terms identical to those contained in this
+    License Agreement (except that you may choose to grant more extensive
+    warranty protection to some or all third parties, at your option).
+
+    c) You may charge a distribution fee for the physical act of
+    transferring a copy, and you may at your option offer warranty
+    protection in exchange for a fee.
+
+Mere aggregation of another unrelated program with this program (or its
+derivative) on a volume of a storage or distribution medium does not bring
+the other program under the scope of these terms.
+
+  3. You may copy and distribute this program or any portion of it in
+compiled, executable or object code form under the terms of Paragraphs
+1 and 2 above provided that you do the following:
+
+    a) accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of
+    Paragraphs 1 and 2 above; or,
+
+    b) accompany it with a written offer, valid for at least three
+    years, to give any third party free (except for a nominal
+    shipping charge) a complete machine-readable copy of the
+    corresponding source code, to be distributed under the terms of
+    Paragraphs 1 and 2 above; or,
+
+    c) accompany it with the information you received as to where the
+    corresponding source code may be obtained.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form alone.)
+
+For an executable file, complete source code means all the source code for
+all modules it contains; but, as a special exception, it need not include
+source code for modules which are standard libraries that accompany the
+operating system on which the executable file runs.
+
+  4. You may not copy, sublicense, distribute or transfer this program
+except as expressly provided under this License Agreement.  Any attempt
+otherwise to copy, sublicense, distribute or transfer this program is void and
+your rights to use the program under this License agreement shall be
+automatically terminated.  However, parties who have received computer
+software programs from you with this License Agreement will not have
+their licenses terminated so long as such parties remain in full compliance.
+
+  5. If you wish to incorporate parts of this program into other free
+programs whose distribution conditions are different, write to the Free
+Software Foundation at 675 Mass Ave, Cambridge, MA 02139.  We have not yet
+worked out a simple rule that can be stated here, but we will often permit
+this.  We will be guided by the two goals of preserving the free status of
+all derivatives our free software and of promoting the sharing and reuse of
+software.
+
+
+In other words, you are welcome to use, share and improve this program.
+You are forbidden to forbid anyone else to use, share and improve
+what you give them.   Help stamp out software-hoarding!  */
+
+#ifdef __STDC__
+
+#ifdef SOMEDAY
+#define ISALNUM(c) isalnum(c)
+#define ISALPHA(c) isalpha(c)
+#define ISUPPER(c) isupper(c)
+#else
+#define ISALNUM(c) (isascii(c) && isalnum(c))
+#define ISALPHA(c) (isascii(c) && isalpha(c))
+#define ISUPPER(c) (isascii(c) && isupper(c))
+#endif
+
+#else /* ! __STDC__ */
+
+#define const
+
+#define ISALNUM(c) (isascii(c) && isalnum(c))
+#define ISALPHA(c) (isascii(c) && isalpha(c))
+#define ISUPPER(c) (isascii(c) && isupper(c))
+
+#endif /* ! __STDC__ */
+
+/* 1 means plain parentheses serve as grouping, and backslash
+     parentheses are needed for literal searching.
+   0 means backslash-parentheses are grouping, and plain parentheses
+     are for literal searching.  */
+#define RE_NO_BK_PARENS 1L
+
+/* 1 means plain | serves as the "or"-operator, and \| is a literal.
+   0 means \| serves as the "or"-operator, and | is a literal.  */
+#define RE_NO_BK_VBAR (1L << 1)
+
+/* 0 means plain + or ? serves as an operator, and \+, \? are literals.
+   1 means \+, \? are operators and plain +, ? are literals.  */
+#define RE_BK_PLUS_QM (1L << 2)
+
+/* 1 means | binds tighter than ^ or $.
+   0 means the contrary.  */
+#define RE_TIGHT_VBAR (1L << 3)
+
+/* 1 means treat \n as an _OR operator
+   0 means treat it as a normal character */
+#define RE_NEWLINE_OR (1L << 4)
+
+/* 0 means that a special characters (such as *, ^, and $) always have
+     their special meaning regardless of the surrounding context.
+   1 means that special characters may act as normal characters in some
+     contexts.  Specifically, this applies to:
+	^ - only special at the beginning, or after ( or |
+	$ - only special at the end, or before ) or |
+	*, +, ? - only special when not after the beginning, (, or | */
+#define RE_CONTEXT_INDEP_OPS (1L << 5)
+
+/* 1 means that \ in a character class escapes the next character (typically
+   a hyphen.  It also is overloaded to mean that hyphen at the end of the range
+   is allowable and means that the hyphen is to be taken literally. */
+#define	RE_AWK_CLASS_HACK (1L << 6)
+
+/* Now define combinations of bits for the standard possibilities.  */
+#ifdef notdef
+#define RE_SYNTAX_AWK (RE_NO_BK_PARENS | RE_NO_BK_VBAR | RE_CONTEXT_INDEP_OPS)
+#define RE_SYNTAX_EGREP (RE_SYNTAX_AWK | RE_NEWLINE_OR)
+#define RE_SYNTAX_GREP (RE_BK_PLUS_QM | RE_NEWLINE_OR)
+#define RE_SYNTAX_EMACS 0
+#endif
+
+/* The NULL pointer. */
+#ifndef NULL
+#define NULL 0
+#endif
+
+/* Number of bits in an unsigned char. */
+#ifndef CHARBITS
+#define CHARBITS 8
+#endif
+
+/* First integer value that is greater than any character code. */
+#define _NOTCHAR (1 << CHARBITS)
+
+/* INTBITS need not be exact, just a lower bound. */
+#ifndef INTBITS
+#define INTBITS (CHARBITS * sizeof (int))
+#endif
+
+/* Number of ints required to hold a bit for every character. */
+#define _CHARSET_INTS ((_NOTCHAR + INTBITS - 1) / INTBITS)
+
+/* Sets of unsigned characters are stored as bit vectors in arrays of ints. */
+typedef int _charset[_CHARSET_INTS];
+
+/* The regexp is parsed into an array of tokens in postfix form.  Some tokens
+   are operators and others are terminal symbols.  Most (but not all) of these
+   codes are returned by the lexical analyzer. */
+#ifdef __STDC__
+
+typedef enum
+{
+  _END = -1,			/* _END is a terminal symbol that matches the
+				   end of input; any value of _END or less in
+				   the parse tree is such a symbol.  Accepting
+				   states of the DFA are those that would have
+				   a transition on _END. */
+
+  /* Ordinary character values are terminal symbols that match themselves. */
+
+  _EMPTY = _NOTCHAR,		/* _EMPTY is a terminal symbol that matches
+				   the empty string. */
+
+  _BACKREF,			/* _BACKREF is generated by \<digit>; it
+				   it not completely handled.  If the scanner
+				   detects a transition on backref, it returns
+				   a kind of "semi-success" indicating that
+				   the match will have to be verified with
+				   a backtracking matcher. */
+
+  _BEGLINE,			/* _BEGLINE is a terminal symbol that matches
+				   the empty string if it is at the beginning
+				   of a line. */
+
+  _ALLBEGLINE,			/* _ALLBEGLINE is a terminal symbol that
+				   matches the empty string if it is at the
+				   beginning of a line; _ALLBEGLINE applies
+				   to the entire regexp and can only occur
+				   as the first token thereof.  _ALLBEGLINE
+				   never appears in the parse tree; a _BEGLINE
+				   is prepended with _CAT to the entire
+				   regexp instead. */
+
+  _ENDLINE,			/* _ENDLINE is a terminal symbol that matches
+				   the empty string if it is at the end of
+				   a line. */
+
+  _ALLENDLINE,			/* _ALLENDLINE is to _ENDLINE as _ALLBEGLINE
+				   is to _BEGLINE. */
+
+  _BEGWORD,			/* _BEGWORD is a terminal symbol that matches
+				   the empty string if it is at the beginning
+				   of a word. */
+
+  _ENDWORD,			/* _ENDWORD is a terminal symbol that matches
+				   the empty string if it is at the end of
+				   a word. */
+
+  _LIMWORD,			/* _LIMWORD is a terminal symbol that matches
+				   the empty string if it is at the beginning
+				   or the end of a word. */
+
+  _NOTLIMWORD,			/* _NOTLIMWORD is a terminal symbol that
+				   matches the empty string if it is not at
+				   the beginning or end of a word. */
+
+  _QMARK,			/* _QMARK is an operator of one argument that
+				   matches zero or one occurences of its
+				   argument. */
+
+  _STAR,			/* _STAR is an operator of one argument that
+				   matches the Kleene closure (zero or more
+				   occurrences) of its argument. */
+
+  _PLUS,			/* _PLUS is an operator of one argument that
+				   matches the positive closure (one or more
+				   occurrences) of its argument. */
+
+  _CAT,				/* _CAT is an operator of two arguments that
+				   matches the concatenation of its
+				   arguments.  _CAT is never returned by the
+				   lexical analyzer. */
+
+  _OR,				/* _OR is an operator of two arguments that
+				   matches either of its arguments. */
+
+  _LPAREN,			/* _LPAREN never appears in the parse tree,
+				   it is only a lexeme. */
+
+  _RPAREN,			/* _RPAREN never appears in the parse tree. */
+
+  _SET				/* _SET and (and any value greater) is a
+				   terminal symbol that matches any of a
+				   class of characters. */
+} _token;
+
+#else /* ! __STDC__ */
+
+typedef short _token;
+
+#define _END -1
+#define _EMPTY _NOTCHAR
+#define _BACKREF (_EMPTY + 1)
+#define _BEGLINE (_EMPTY + 2)
+#define _ALLBEGLINE (_EMPTY + 3)
+#define _ENDLINE (_EMPTY + 4)
+#define _ALLENDLINE (_EMPTY + 5)
+#define _BEGWORD (_EMPTY + 6)
+#define _ENDWORD (_EMPTY + 7)
+#define _LIMWORD (_EMPTY + 8)
+#define _NOTLIMWORD (_EMPTY + 9)
+#define _QMARK (_EMPTY + 10)
+#define _STAR (_EMPTY + 11)
+#define _PLUS (_EMPTY + 12)
+#define _CAT (_EMPTY + 13)
+#define _OR (_EMPTY + 14)
+#define _LPAREN (_EMPTY + 15)
+#define _RPAREN (_EMPTY + 16)
+#define _SET (_EMPTY + 17)
+
+#endif /* ! __STDC__ */
+
+/* Sets are stored in an array in the compiled regexp; the index of the
+   array corresponding to a given set token is given by _SET_INDEX(t). */
+#define _SET_INDEX(t) ((t) - _SET)
+
+/* Sometimes characters can only be matched depending on the surrounding
+   context.  Such context decisions depend on what the previous character
+   was, and the value of the current (lookahead) character.  Context
+   dependent constraints are encoded as 8 bit integers.  Each bit that
+   is set indicates that the constraint succeeds in the corresponding
+   context.
+
+   bit 7 - previous and current are newlines
+   bit 6 - previous was newline, current isn't
+   bit 5 - previous wasn't newline, current is
+   bit 4 - neither previous nor current is a newline
+   bit 3 - previous and current are word-constituents
+   bit 2 - previous was word-constituent, current isn't
+   bit 1 - previous wasn't word-constituent, current is
+   bit 0 - neither previous nor current is word-constituent
+
+   Word-constituent characters are those that satisfy isalnum().
+
+   The macro _SUCCEEDS_IN_CONTEXT determines whether a a given constraint
+   succeeds in a particular context.  Prevn is true if the previous character
+   was a newline, currn is true if the lookahead character is a newline.
+   Prevl and currl similarly depend upon whether the previous and current
+   characters are word-constituent letters. */
+#define _MATCHES_NEWLINE_CONTEXT(constraint, prevn, currn) \
+  ((constraint) & (1 << (((prevn) ? 2 : 0) + ((currn) ? 1 : 0) + 4)))
+#define _MATCHES_LETTER_CONTEXT(constraint, prevl, currl) \
+  ((constraint) & (1 << (((prevl) ? 2 : 0) + ((currl) ? 1 : 0))))
+#define _SUCCEEDS_IN_CONTEXT(constraint, prevn, currn, prevl, currl) \
+  (_MATCHES_NEWLINE_CONTEXT(constraint, prevn, currn)		     \
+   && _MATCHES_LETTER_CONTEXT(constraint, prevl, currl))
+
+/* The following macros give information about what a constraint depends on. */
+#define _PREV_NEWLINE_DEPENDENT(constraint) \
+  (((constraint) & 0xc0) >> 2 != ((constraint) & 0x30))
+#define _PREV_LETTER_DEPENDENT(constraint) \
+  (((constraint) & 0x0c) >> 2 != ((constraint) & 0x03))
+
+/* Tokens that match the empty string subject to some constraint actually
+   work by applying that constraint to determine what may follow them,
+   taking into account what has gone before.  The following values are
+   the constraints corresponding to the special tokens previously defined. */
+#define _NO_CONSTRAINT 0xff
+#define _BEGLINE_CONSTRAINT 0xcf
+#define _ENDLINE_CONSTRAINT 0xaf
+#define _BEGWORD_CONSTRAINT 0xf2
+#define _ENDWORD_CONSTRAINT 0xf4
+#define _LIMWORD_CONSTRAINT 0xf6
+#define _NOTLIMWORD_CONSTRAINT 0xf9
+
+/* States of the recognizer correspond to sets of positions in the parse
+   tree, together with the constraints under which they may be matched.
+   So a position is encoded as an index into the parse tree together with
+   a constraint. */
+typedef struct
+{
+  unsigned index;		/* Index into the parse array. */
+  unsigned constraint;		/* Constraint for matching this position. */
+} _position;
+
+/* Sets of positions are stored as arrays. */
+typedef struct
+{
+  _position *elems;		/* Elements of this position set. */
+  int nelem;			/* Number of elements in this set. */
+} _position_set;
+
+/* A state of the regexp consists of a set of positions, some flags,
+   and the token value of the lowest-numbered position of the state that
+   contains an _END token. */
+typedef struct
+{
+  int hash;			/* Hash of the positions of this state. */
+  _position_set elems;		/* Positions this state could match. */
+  char newline;			/* True if previous state matched newline. */
+  char letter;			/* True if previous state matched a letter. */
+  char backref;			/* True if this state matches a \<digit>. */
+  unsigned char constraint;	/* Constraint for this state to accept. */
+  int first_end;		/* Token value of the first _END in elems. */
+} _dfa_state;
+
+/* If an r.e. is at most MUST_MAX characters long, we look for a string which
+   must appear in it; whatever's found is dropped into the struct reg. */
+
+#define MUST_MAX	50
+
+/* A compiled regular expression. */
+struct regexp
+{
+  /* Stuff built by the scanner. */
+  _charset *charsets;		/* Array of character sets for _SET tokens. */
+  int cindex;			/* Index for adding new charsets. */
+  int calloc;			/* Number of charsets currently allocated. */
+
+  /* Stuff built by the parser. */
+  _token *tokens;		/* Postfix parse array. */
+  int tindex;			/* Index for adding new tokens. */
+  int talloc;			/* Number of tokens currently allocated. */
+  int depth;			/* Depth required of an evaluation stack
+				   used for depth-first traversal of the
+				   parse tree. */
+  int nleaves;			/* Number of leaves on the parse tree. */
+  int nregexps;			/* Count of parallel regexps being built
+				   with regparse(). */
+
+  /* Stuff owned by the state builder. */
+  _dfa_state *states;		/* States of the regexp. */
+  int sindex;			/* Index for adding new states. */
+  int salloc;			/* Number of states currently allocated. */
+
+  /* Stuff built by the structure analyzer. */
+  _position_set *follows;	/* Array of follow sets, indexed by position
+				   index.  The follow of a position is the set
+				   of positions containing characters that
+				   could conceivably follow a character
+				   matching the given position in a string
+				   matching the regexp.  Allocated to the
+				   maximum possible position index. */
+  int searchflag;		/* True if we are supposed to build a searching
+				   as opposed to an exact matcher.  A searching
+				   matcher finds the first and shortest string
+				   matching a regexp anywhere in the buffer,
+				   whereas an exact matcher finds the longest
+				   string matching, but anchored to the
+				   beginning of the buffer. */
+
+  /* Stuff owned by the executor. */
+  int tralloc;			/* Number of transition tables that have
+				   slots so far. */
+  int trcount;			/* Number of transition tables that have
+				   actually been built. */
+  int **trans;			/* Transition tables for states that can
+				   never accept.  If the transitions for a
+				   state have not yet been computed, or the
+				   state could possibly accept, its entry in
+				   this table is NULL. */
+  int **realtrans;		/* Trans always points to realtrans + 1; this
+				   is so trans[-1] can contain NULL. */
+  int **fails;			/* Transition tables after failing to accept
+				   on a state that potentially could do so. */
+  int *success;			/* Table of acceptance conditions used in
+				   regexecute and computed in build_state. */
+  int *newlines;		/* Transitions on newlines.  The entry for a
+				   newline in any transition table is always
+				   -1 so we can count lines without wasting
+				   too many cycles.  The transition for a
+				   newline is stored separately and handled
+				   as a special case.  Newline is also used
+				   as a sentinel at the end of the buffer. */
+  char must[MUST_MAX];
+  int mustn;
+};
+
+/* Some macros for user access to regexp internals. */
+
+/* ACCEPTING returns true if s could possibly be an accepting state of r. */
+#define ACCEPTING(s, r) ((r).states[s].constraint)
+
+/* ACCEPTS_IN_CONTEXT returns true if the given state accepts in the
+   specified context. */
+#define ACCEPTS_IN_CONTEXT(prevn, currn, prevl, currl, state, reg) \
+  _SUCCEEDS_IN_CONTEXT((reg).states[state].constraint,		   \
+		       prevn, currn, prevl, currl)
+
+/* FIRST_MATCHING_REGEXP returns the index number of the first of parallel
+   regexps that a given state could accept.  Parallel regexps are numbered
+   starting at 1. */
+#define FIRST_MATCHING_REGEXP(state, reg) (-(reg).states[state].first_end)
+
+/* Entry points. */
+
+#ifdef __STDC__
+
+/* Regsyntax() takes two arguments; the first sets the syntax bits described
+   earlier in this file, and the second sets the case-folding flag. */
+extern void regsyntax(long, int);
+
+/* Compile the given string of the given length into the given struct regexp.
+   Final argument is a flag specifying whether to build a searching or an
+   exact matcher. */
+extern void regcompile(const char *, size_t, struct regexp *, int);
+
+/* Execute the given struct regexp on the buffer of characters.  The
+   first char * points to the beginning, and the second points to the
+   first character after the end of the buffer, which must be a writable
+   place so a sentinel end-of-buffer marker can be stored there.  The
+   second-to-last argument is a flag telling whether to allow newlines to
+   be part of a string matching the regexp.  The next-to-last argument,
+   if non-NULL, points to a place to increment every time we see a
+   newline.  The final argument, if non-NULL, points to a flag that will
+   be set if further examination by a backtracking matcher is needed in
+   order to verify backreferencing; otherwise the flag will be cleared.
+   Returns NULL if no match is found, or a pointer to the first
+   character after the first & shortest matching string in the buffer. */
+extern char *regexecute(struct regexp *, char *, char *, int, int *, int *);
+
+/* Free the storage held by the components of a struct regexp. */
+extern void reg_free(struct regexp *);
+
+/* Entry points for people who know what they're doing. */
+
+/* Initialize the components of a struct regexp. */
+extern void reginit(struct regexp *);
+
+/* Incrementally parse a string of given length into a struct regexp. */
+extern void regparse(const char *, size_t, struct regexp *);
+
+/* Analyze a parsed regexp; second argument tells whether to build a searching
+   or an exact matcher. */
+extern void reganalyze(struct regexp *, int);
+
+/* Compute, for each possible character, the transitions out of a given
+   state, storing them in an array of integers. */
+extern void regstate(int, struct regexp *, int []);
+
+/* Error handling. */
+
+/* Regerror() is called by the regexp routines whenever an error occurs.  It
+   takes a single argument, a NUL-terminated string describing the error.
+   The default reg_error() prints the error message to stderr and exits.
+   The user can provide a different reg_free() if so desired. */
+extern void reg_error(const char *);
+
+#else /* ! __STDC__ */
+extern void regsyntax(), regcompile(), reg_free(), reginit(), regparse();
+extern void reganalyze(), regstate(), reg_error();
+extern char *regexecute();
+#endif
diff --git a/gnu/usr.bin/awk/eval.c b/gnu/usr.bin/awk/eval.c
new file mode 100644
index 000000000000..f640f3733ada
--- /dev/null
+++ b/gnu/usr.bin/awk/eval.c
@@ -0,0 +1,1225 @@
+/*
+ * eval.c - gawk parse tree interpreter 
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "awk.h"
+
+extern double pow P((double x, double y));
+extern double modf P((double x, double *yp));
+extern double fmod P((double x, double y));
+
+static int eval_condition P((NODE *tree));
+static NODE *op_assign P((NODE *tree));
+static NODE *func_call P((NODE *name, NODE *arg_list));
+static NODE *match_op P((NODE *tree));
+
+NODE *_t;		/* used as a temporary in macros */
+#ifdef MSDOS
+double _msc51bug;	/* to get around a bug in MSC 5.1 */
+#endif
+NODE *ret_node;
+int OFSlen;
+int ORSlen;
+int OFMTidx;
+int CONVFMTidx;
+
+/* Macros and variables to save and restore function and loop bindings */
+/*
+ * the val variable allows return/continue/break-out-of-context to be
+ * caught and diagnosed
+ */
+#define PUSH_BINDING(stack, x, val) (memcpy ((char *)(stack), (char *)(x), sizeof (jmp_buf)), val++)
+#define RESTORE_BINDING(stack, x, val) (memcpy ((char *)(x), (char *)(stack), sizeof (jmp_buf)), val--)
+
+static jmp_buf loop_tag;	/* always the current binding */
+static int loop_tag_valid = 0;	/* nonzero when loop_tag valid */
+static int func_tag_valid = 0;
+static jmp_buf func_tag;
+extern int exiting, exit_val;
+
+/*
+ * This table is used by the regexp routines to do case independant
+ * matching. Basically, every ascii character maps to itself, except
+ * uppercase letters map to lower case ones. This table has 256
+ * entries, which may be overkill. Note also that if the system this
+ * is compiled on doesn't use 7-bit ascii, casetable[] should not be
+ * defined to the linker, so gawk should not load.
+ *
+ * Do NOT make this array static, it is used in several spots, not
+ * just in this file.
+ */
+#if 'a' == 97	/* it's ascii */
+char casetable[] = {
+	'\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007',
+	'\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017',
+	'\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027',
+	'\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037',
+	/* ' '     '!'     '"'     '#'     '$'     '%'     '&'     ''' */
+	'\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047',
+	/* '('     ')'     '*'     '+'     ','     '-'     '.'     '/' */
+	'\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057',
+	/* '0'     '1'     '2'     '3'     '4'     '5'     '6'     '7' */
+	'\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067',
+	/* '8'     '9'     ':'     ';'     '<'     '='     '>'     '?' */
+	'\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077',
+	/* '@'     'A'     'B'     'C'     'D'     'E'     'F'     'G' */
+	'\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
+	/* 'H'     'I'     'J'     'K'     'L'     'M'     'N'     'O' */
+	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
+	/* 'P'     'Q'     'R'     'S'     'T'     'U'     'V'     'W' */
+	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
+	/* 'X'     'Y'     'Z'     '['     '\'     ']'     '^'     '_' */
+	'\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137',
+	/* '`'     'a'     'b'     'c'     'd'     'e'     'f'     'g' */
+	'\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
+	/* 'h'     'i'     'j'     'k'     'l'     'm'     'n'     'o' */
+	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
+	/* 'p'     'q'     'r'     's'     't'     'u'     'v'     'w' */
+	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
+	/* 'x'     'y'     'z'     '{'     '|'     '}'     '~' */
+	'\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177',
+	'\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207',
+	'\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217',
+	'\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227',
+	'\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237',
+	'\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247',
+	'\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257',
+	'\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267',
+	'\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277',
+	'\300', '\301', '\302', '\303', '\304', '\305', '\306', '\307',
+	'\310', '\311', '\312', '\313', '\314', '\315', '\316', '\317',
+	'\320', '\321', '\322', '\323', '\324', '\325', '\326', '\327',
+	'\330', '\331', '\332', '\333', '\334', '\335', '\336', '\337',
+	'\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
+	'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
+	'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
+	'\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377',
+};
+#else
+#include "You lose. You will need a translation table for your character set."
+#endif
+
+/*
+ * Tree is a bunch of rules to run. Returns zero if it hit an exit()
+ * statement 
+ */
+int
+interpret(tree)
+register NODE *volatile tree;
+{
+	jmp_buf volatile loop_tag_stack; /* shallow binding stack for loop_tag */
+	static jmp_buf rule_tag; /* tag the rule currently being run, for NEXT
+				  * and EXIT statements.  It is static because
+				  * there are no nested rules */
+	register NODE *volatile t = NULL;	/* temporary */
+	NODE **volatile lhs;	/* lhs == Left Hand Side for assigns, etc */
+	NODE *volatile stable_tree;
+	int volatile traverse = 1;	/* True => loop thru tree (Node_rule_list) */
+
+	if (tree == NULL)
+		return 1;
+	sourceline = tree->source_line;
+	source = tree->source_file;
+	switch (tree->type) {
+	case Node_rule_node:
+		traverse = 0;   /* False => one for-loop iteration only */
+		/* FALL THROUGH */
+	case Node_rule_list:
+		for (t = tree; t != NULL; t = t->rnode) {
+			if (traverse)
+				tree = t->lnode;
+			sourceline = tree->source_line;
+			source = tree->source_file;
+			switch (setjmp(rule_tag)) {
+			case 0:	/* normal non-jump */
+				/* test pattern, if any */
+				if (tree->lnode == NULL ||
+				    eval_condition(tree->lnode))
+					(void) interpret(tree->rnode);
+				break;
+			case TAG_CONTINUE:	/* NEXT statement */
+				return 1;
+			case TAG_BREAK:
+				return 0;
+			default:
+				cant_happen();
+			}
+			if (!traverse)          /* case Node_rule_node */
+				break;          /* don't loop */
+		}
+		break;
+
+	case Node_statement_list:
+		for (t = tree; t != NULL; t = t->rnode)
+			(void) interpret(t->lnode);
+		break;
+
+	case Node_K_if:
+		if (eval_condition(tree->lnode)) {
+			(void) interpret(tree->rnode->lnode);
+		} else {
+			(void) interpret(tree->rnode->rnode);
+		}
+		break;
+
+	case Node_K_while:
+		PUSH_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+
+		stable_tree = tree;
+		while (eval_condition(stable_tree->lnode)) {
+			switch (setjmp(loop_tag)) {
+			case 0:	/* normal non-jump */
+				(void) interpret(stable_tree->rnode);
+				break;
+			case TAG_CONTINUE:	/* continue statement */
+				break;
+			case TAG_BREAK:	/* break statement */
+				RESTORE_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+				return 1;
+			default:
+				cant_happen();
+			}
+		}
+		RESTORE_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+		break;
+
+	case Node_K_do:
+		PUSH_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+		stable_tree = tree;
+		do {
+			switch (setjmp(loop_tag)) {
+			case 0:	/* normal non-jump */
+				(void) interpret(stable_tree->rnode);
+				break;
+			case TAG_CONTINUE:	/* continue statement */
+				break;
+			case TAG_BREAK:	/* break statement */
+				RESTORE_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+				return 1;
+			default:
+				cant_happen();
+			}
+		} while (eval_condition(stable_tree->lnode));
+		RESTORE_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+		break;
+
+	case Node_K_for:
+		PUSH_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+		(void) interpret(tree->forloop->init);
+		stable_tree = tree;
+		while (eval_condition(stable_tree->forloop->cond)) {
+			switch (setjmp(loop_tag)) {
+			case 0:	/* normal non-jump */
+				(void) interpret(stable_tree->lnode);
+				/* fall through */
+			case TAG_CONTINUE:	/* continue statement */
+				(void) interpret(stable_tree->forloop->incr);
+				break;
+			case TAG_BREAK:	/* break statement */
+				RESTORE_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+				return 1;
+			default:
+				cant_happen();
+			}
+		}
+		RESTORE_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+		break;
+
+	case Node_K_arrayfor:
+		{
+		volatile struct search l;	/* For array_for */
+		Func_ptr after_assign = NULL;
+
+#define hakvar forloop->init
+#define arrvar forloop->incr
+		PUSH_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+		lhs = get_lhs(tree->hakvar, &after_assign);
+		t = tree->arrvar;
+		if (t->type == Node_param_list)
+			t = stack_ptr[t->param_cnt];
+		stable_tree = tree;
+		for (assoc_scan(t, (struct search *)&l);
+		     l.retval;
+		     assoc_next((struct search *)&l)) {
+			unref(*((NODE **) lhs));
+			*lhs = dupnode(l.retval);
+			if (after_assign)
+				(*after_assign)();
+			switch (setjmp(loop_tag)) {
+			case 0:
+				(void) interpret(stable_tree->lnode);
+			case TAG_CONTINUE:
+				break;
+
+			case TAG_BREAK:
+				RESTORE_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+				return 1;
+			default:
+				cant_happen();
+			}
+		}
+		RESTORE_BINDING(loop_tag_stack, loop_tag, loop_tag_valid);
+		break;
+		}
+
+	case Node_K_break:
+		if (loop_tag_valid == 0)
+			fatal("unexpected break");
+		longjmp(loop_tag, TAG_BREAK);
+		break;
+
+	case Node_K_continue:
+		if (loop_tag_valid == 0) {
+			/*
+			 * AT&T nawk treats continue outside of loops like
+			 * next.  Allow it if not posix, and complain if
+			 * lint.
+			 */
+			static int warned = 0;
+
+			if (do_lint && ! warned) {
+				warning("use of `continue' outside of loop is not portable");
+				warned = 1;
+			}
+			if (do_posix)
+				fatal("use of `continue' outside of loop is not allowed");
+			longjmp(rule_tag, TAG_CONTINUE);
+		} else
+			longjmp(loop_tag, TAG_CONTINUE);
+		break;
+
+	case Node_K_print:
+		do_print(tree);
+		break;
+
+	case Node_K_printf:
+		do_printf(tree);
+		break;
+
+	case Node_K_delete:
+		do_delete(tree->lnode, tree->rnode);
+		break;
+
+	case Node_K_next:
+		longjmp(rule_tag, TAG_CONTINUE);
+		break;
+
+	case Node_K_nextfile:
+		do_nextfile();
+		break;
+
+	case Node_K_exit:
+		/*
+		 * In A,K,&W, p. 49, it says that an exit statement "...
+		 * causes the program to behave as if the end of input had
+		 * occurred; no more input is read, and the END actions, if
+		 * any are executed." This implies that the rest of the rules
+		 * are not done. So we immediately break out of the main loop.
+		 */
+		exiting = 1;
+		if (tree) {
+			t = tree_eval(tree->lnode);
+			exit_val = (int) force_number(t);
+		}
+		free_temp(t);
+		longjmp(rule_tag, TAG_BREAK);
+		break;
+
+	case Node_K_return:
+		t = tree_eval(tree->lnode);
+		ret_node = dupnode(t);
+		free_temp(t);
+		longjmp(func_tag, TAG_RETURN);
+		break;
+
+	default:
+		/*
+		 * Appears to be an expression statement.  Throw away the
+		 * value. 
+		 */
+		if (do_lint && tree->type == Node_var)
+			warning("statement has no effect");
+		t = tree_eval(tree);
+		free_temp(t);
+		break;
+	}
+	return 1;
+}
+
+/* evaluate a subtree */
+
+NODE *
+r_tree_eval(tree)
+register NODE *tree;
+{
+	register NODE *r, *t1, *t2;	/* return value & temporary subtrees */
+	register NODE **lhs;
+	register int di;
+	AWKNUM x, x1, x2;
+	long lx;
+#ifdef CRAY
+	long lx2;
+#endif
+
+#ifdef DEBUG
+	if (tree == NULL)
+		return Nnull_string;
+	if (tree->type == Node_val) {
+		if (tree->stref <= 0) cant_happen();
+		return tree;
+	}
+	if (tree->type == Node_var) {
+		if (tree->var_value->stref <= 0) cant_happen();
+		return tree->var_value;
+	}
+	if (tree->type == Node_param_list) {
+		if (stack_ptr[tree->param_cnt] == NULL)
+			return Nnull_string;
+		else
+			return stack_ptr[tree->param_cnt]->var_value;
+	}
+#endif
+	switch (tree->type) {
+	case Node_and:
+		return tmp_number((AWKNUM) (eval_condition(tree->lnode)
+					    && eval_condition(tree->rnode)));
+
+	case Node_or:
+		return tmp_number((AWKNUM) (eval_condition(tree->lnode)
+					    || eval_condition(tree->rnode)));
+
+	case Node_not:
+		return tmp_number((AWKNUM) ! eval_condition(tree->lnode));
+
+		/* Builtins */
+	case Node_builtin:
+		return ((*tree->proc) (tree->subnode));
+
+	case Node_K_getline:
+		return (do_getline(tree));
+
+	case Node_in_array:
+		return tmp_number((AWKNUM) in_array(tree->lnode, tree->rnode));
+
+	case Node_func_call:
+		return func_call(tree->rnode, tree->lnode);
+
+		/* unary operations */
+	case Node_NR:
+	case Node_FNR:
+	case Node_NF:
+	case Node_FIELDWIDTHS:
+	case Node_FS:
+	case Node_RS:
+	case Node_field_spec:
+	case Node_subscript:
+	case Node_IGNORECASE:
+	case Node_OFS:
+	case Node_ORS:
+	case Node_OFMT:
+	case Node_CONVFMT:
+		lhs = get_lhs(tree, (Func_ptr *)0);
+		return *lhs;
+
+	case Node_var_array:
+		fatal("attempt to use an array in a scalar context");
+
+	case Node_unary_minus:
+		t1 = tree_eval(tree->subnode);
+		x = -force_number(t1);
+		free_temp(t1);
+		return tmp_number(x);
+
+	case Node_cond_exp:
+		if (eval_condition(tree->lnode))
+			return tree_eval(tree->rnode->lnode);
+		return tree_eval(tree->rnode->rnode);
+
+	case Node_match:
+	case Node_nomatch:
+	case Node_regex:
+		return match_op(tree);
+
+	case Node_func:
+		fatal("function `%s' called with space between name and (,\n%s",
+			tree->lnode->param,
+			"or used in other expression context");
+
+		/* assignments */
+	case Node_assign:
+		{
+		Func_ptr after_assign = NULL;
+
+		r = tree_eval(tree->rnode);
+		lhs = get_lhs(tree->lnode, &after_assign);
+		if (r != *lhs) {
+			NODE *save;
+
+			save = *lhs;
+			*lhs = dupnode(r);
+			unref(save);
+		}
+		free_temp(r);
+		if (after_assign)
+			(*after_assign)();
+		return *lhs;
+		}
+
+	case Node_concat:
+		{
+#define	STACKSIZE	10
+		NODE *stack[STACKSIZE];
+		register NODE **sp;
+		register int len;
+		char *str;
+		register char *dest;
+
+		sp = stack;
+		len = 0;
+		while (tree->type == Node_concat) {
+			*sp = force_string(tree_eval(tree->lnode));
+			tree = tree->rnode;
+			len += (*sp)->stlen;
+			if (++sp == &stack[STACKSIZE-2]) /* one more and NULL */
+				break;
+		}
+		*sp = force_string(tree_eval(tree));
+		len += (*sp)->stlen;
+		*++sp = NULL;
+		emalloc(str, char *, len+2, "tree_eval");
+		dest = str;
+		sp = stack;
+		while (*sp) {
+			memcpy(dest, (*sp)->stptr, (*sp)->stlen);
+			dest += (*sp)->stlen;
+			free_temp(*sp);
+			sp++;
+		}
+		r = make_str_node(str, len, ALREADY_MALLOCED);
+		r->flags |= TEMP;
+		}
+		return r;
+
+	/* other assignment types are easier because they are numeric */
+	case Node_preincrement:
+	case Node_predecrement:
+	case Node_postincrement:
+	case Node_postdecrement:
+	case Node_assign_exp:
+	case Node_assign_times:
+	case Node_assign_quotient:
+	case Node_assign_mod:
+	case Node_assign_plus:
+	case Node_assign_minus:
+		return op_assign(tree);
+	default:
+		break;	/* handled below */
+	}
+
+	/* evaluate subtrees in order to do binary operation, then keep going */
+	t1 = tree_eval(tree->lnode);
+	t2 = tree_eval(tree->rnode);
+
+	switch (tree->type) {
+	case Node_geq:
+	case Node_leq:
+	case Node_greater:
+	case Node_less:
+	case Node_notequal:
+	case Node_equal:
+		di = cmp_nodes(t1, t2);
+		free_temp(t1);
+		free_temp(t2);
+		switch (tree->type) {
+		case Node_equal:
+			return tmp_number((AWKNUM) (di == 0));
+		case Node_notequal:
+			return tmp_number((AWKNUM) (di != 0));
+		case Node_less:
+			return tmp_number((AWKNUM) (di < 0));
+		case Node_greater:
+			return tmp_number((AWKNUM) (di > 0));
+		case Node_leq:
+			return tmp_number((AWKNUM) (di <= 0));
+		case Node_geq:
+			return tmp_number((AWKNUM) (di >= 0));
+		default:
+			cant_happen();
+		}
+		break;
+	default:
+		break;	/* handled below */
+	}
+
+	x1 = force_number(t1);
+	free_temp(t1);
+	x2 = force_number(t2);
+	free_temp(t2);
+	switch (tree->type) {
+	case Node_exp:
+		if ((lx = x2) == x2 && lx >= 0) {	/* integer exponent */
+			if (lx == 0)
+				x = 1;
+			else if (lx == 1)
+				x = x1;
+			else {
+				/* doing it this way should be more precise */
+				for (x = x1; --lx; )
+					x *= x1;
+			}
+		} else
+			x = pow((double) x1, (double) x2);
+		return tmp_number(x);
+
+	case Node_times:
+		return tmp_number(x1 * x2);
+
+	case Node_quotient:
+		if (x2 == 0)
+			fatal("division by zero attempted");
+#ifdef _CRAY
+		/*
+		 * special case for integer division, put in for Cray
+		 */
+		lx2 = x2;
+		if (lx2 == 0)
+			return tmp_number(x1 / x2);
+		lx = (long) x1 / lx2;
+		if (lx * x2 == x1)
+			return tmp_number((AWKNUM) lx);
+		else
+#endif
+			return tmp_number(x1 / x2);
+
+	case Node_mod:
+		if (x2 == 0)
+			fatal("division by zero attempted in mod");
+#ifndef FMOD_MISSING
+		return tmp_number(fmod (x1, x2));
+#else
+		(void) modf(x1 / x2, &x);
+		return tmp_number(x1 - x * x2);
+#endif
+
+	case Node_plus:
+		return tmp_number(x1 + x2);
+
+	case Node_minus:
+		return tmp_number(x1 - x2);
+
+	case Node_var_array:
+		fatal("attempt to use an array in a scalar context");
+
+	default:
+		fatal("illegal type (%d) in tree_eval", tree->type);
+	}
+	return 0;
+}
+
+/* Is TREE true or false?  Returns 0==false, non-zero==true */
+static int
+eval_condition(tree)
+register NODE *tree;
+{
+	register NODE *t1;
+	register int ret;
+
+	if (tree == NULL)	/* Null trees are the easiest kinds */
+		return 1;
+	if (tree->type == Node_line_range) {
+		/*
+		 * Node_line_range is kind of like Node_match, EXCEPT: the
+		 * lnode field (more properly, the condpair field) is a node
+		 * of a Node_cond_pair; whether we evaluate the lnode of that
+		 * node or the rnode depends on the triggered word.  More
+		 * precisely:  if we are not yet triggered, we tree_eval the
+		 * lnode; if that returns true, we set the triggered word. 
+		 * If we are triggered (not ELSE IF, note), we tree_eval the
+		 * rnode, clear triggered if it succeeds, and perform our
+		 * action (regardless of success or failure).  We want to be
+		 * able to begin and end on a single input record, so this
+		 * isn't an ELSE IF, as noted above.
+		 */
+		if (!tree->triggered)
+			if (!eval_condition(tree->condpair->lnode))
+				return 0;
+			else
+				tree->triggered = 1;
+		/* Else we are triggered */
+		if (eval_condition(tree->condpair->rnode))
+			tree->triggered = 0;
+		return 1;
+	}
+
+	/*
+	 * Could just be J.random expression. in which case, null and 0 are
+	 * false, anything else is true 
+	 */
+
+	t1 = tree_eval(tree);
+	if (t1->flags & MAYBE_NUM)
+		(void) force_number(t1);
+	if (t1->flags & NUMBER)
+		ret = t1->numbr != 0.0;
+	else
+		ret = t1->stlen != 0;
+	free_temp(t1);
+	return ret;
+}
+
+/*
+ * compare two nodes, returning negative, 0, positive
+ */
+int
+cmp_nodes(t1, t2)
+register NODE *t1, *t2;
+{
+	register int ret;
+	register int len1, len2;
+
+	if (t1 == t2)
+		return 0;
+	if (t1->flags & MAYBE_NUM)
+		(void) force_number(t1);
+	if (t2->flags & MAYBE_NUM)
+		(void) force_number(t2);
+	if ((t1->flags & NUMBER) && (t2->flags & NUMBER)) {
+		if (t1->numbr == t2->numbr) return 0;
+		else if (t1->numbr - t2->numbr < 0)  return -1;
+		else return 1;
+	}
+	(void) force_string(t1);
+	(void) force_string(t2);
+	len1 = t1->stlen;
+	len2 = t2->stlen;
+	if (len1 == 0 || len2 == 0)
+		return len1 - len2;
+	ret = memcmp(t1->stptr, t2->stptr, len1 <= len2 ? len1 : len2);
+	return ret == 0 ? len1-len2 : ret;
+}
+
+static NODE *
+op_assign(tree)
+register NODE *tree;
+{
+	AWKNUM rval, lval;
+	NODE **lhs;
+	AWKNUM t1, t2;
+	long ltemp;
+	NODE *tmp;
+	Func_ptr after_assign = NULL;
+
+	lhs = get_lhs(tree->lnode, &after_assign);
+	lval = force_number(*lhs);
+
+	/*
+	 * Can't unref *lhs until we know the type; doing so
+	 * too early breaks   x += x   sorts of things.
+	 */
+	switch(tree->type) {
+	case Node_preincrement:
+	case Node_predecrement:
+		unref(*lhs);
+		*lhs = make_number(lval +
+			       (tree->type == Node_preincrement ? 1.0 : -1.0));
+		if (after_assign)
+			(*after_assign)();
+		return *lhs;
+
+	case Node_postincrement:
+	case Node_postdecrement:
+		unref(*lhs);
+		*lhs = make_number(lval +
+			       (tree->type == Node_postincrement ? 1.0 : -1.0));
+		if (after_assign)
+			(*after_assign)();
+		return tmp_number(lval);
+	default:
+		break;	/* handled below */
+	}
+
+	tmp = tree_eval(tree->rnode);
+	rval = force_number(tmp);
+	free_temp(tmp);
+	unref(*lhs);
+	switch(tree->type) {
+	case Node_assign_exp:
+		if ((ltemp = rval) == rval) {	/* integer exponent */
+			if (ltemp == 0)
+				*lhs = make_number((AWKNUM) 1);
+			else if (ltemp == 1)
+				*lhs = make_number(lval);
+			else {
+				/* doing it this way should be more precise */
+				for (t1 = t2 = lval; --ltemp; )
+					t1 *= t2;
+				*lhs = make_number(t1);
+			}
+		} else
+			*lhs = make_number((AWKNUM) pow((double) lval, (double) rval));
+		break;
+
+	case Node_assign_times:
+		*lhs = make_number(lval * rval);
+		break;
+
+	case Node_assign_quotient:
+		if (rval == (AWKNUM) 0)
+			fatal("division by zero attempted in /=");
+#ifdef _CRAY
+		/*
+		 * special case for integer division, put in for Cray
+		 */
+		ltemp = rval;
+		if (ltemp == 0) {
+			*lhs = make_number(lval / rval);
+			break;
+		}
+		ltemp = (long) lval / ltemp;
+		if (ltemp * lval == rval)
+			*lhs = make_number((AWKNUM) ltemp);
+		else
+#endif
+			*lhs = make_number(lval / rval);
+		break;
+
+	case Node_assign_mod:
+		if (rval == (AWKNUM) 0)
+			fatal("division by zero attempted in %=");
+#ifndef FMOD_MISSING
+		*lhs = make_number(fmod(lval, rval));
+#else
+		(void) modf(lval / rval, &t1);
+		t2 = lval - rval * t1;
+		*lhs = make_number(t2);
+#endif
+		break;
+
+	case Node_assign_plus:
+		*lhs = make_number(lval + rval);
+		break;
+
+	case Node_assign_minus:
+		*lhs = make_number(lval - rval);
+		break;
+	default:
+		cant_happen();
+	}
+	if (after_assign)
+		(*after_assign)();
+	return *lhs;
+}
+
+NODE **stack_ptr;
+
+static NODE *
+func_call(name, arg_list)
+NODE *name;		/* name is a Node_val giving function name */
+NODE *arg_list;		/* Node_expression_list of calling args. */
+{
+	register NODE *arg, *argp, *r;
+	NODE *n, *f;
+	jmp_buf volatile func_tag_stack;
+	jmp_buf volatile loop_tag_stack;
+	int volatile save_loop_tag_valid = 0;
+	NODE **volatile save_stack, *save_ret_node;
+	NODE **volatile local_stack = NULL, **sp;
+	int count;
+	extern NODE *ret_node;
+
+	/*
+	 * retrieve function definition node
+	 */
+	f = lookup(name->stptr);
+	if (!f || f->type != Node_func)
+		fatal("function `%s' not defined", name->stptr);
+#ifdef FUNC_TRACE
+	fprintf(stderr, "function %s called\n", name->stptr);
+#endif
+	count = f->lnode->param_cnt;
+	if (count)
+		emalloc(local_stack, NODE **, count*sizeof(NODE *), "func_call");
+	sp = local_stack;
+
+	/*
+	 * for each calling arg. add NODE * on stack
+	 */
+	for (argp = arg_list; count && argp != NULL; argp = argp->rnode) {
+		arg = argp->lnode;
+		getnode(r);
+		r->type = Node_var;
+		/*
+		 * call by reference for arrays; see below also
+		 */
+		if (arg->type == Node_param_list)
+			arg = stack_ptr[arg->param_cnt];
+		if (arg->type == Node_var_array)
+			*r = *arg;
+		else {
+			n = tree_eval(arg);
+			r->lnode = dupnode(n);
+			r->rnode = (NODE *) NULL;
+			free_temp(n);
+  		}
+		*sp++ = r;
+		count--;
+	}
+	if (argp != NULL)	/* left over calling args. */
+		warning(
+		    "function `%s' called with more arguments than declared",
+		    name->stptr);
+	/*
+	 * add remaining params. on stack with null value
+	 */
+	while (count-- > 0) {
+		getnode(r);
+		r->type = Node_var;
+		r->lnode = Nnull_string;
+		r->rnode = (NODE *) NULL;
+		*sp++ = r;
+	}
+
+	/*
+	 * Execute function body, saving context, as a return statement
+	 * will longjmp back here.
+	 *
+	 * Have to save and restore the loop_tag stuff so that a return
+	 * inside a loop in a function body doesn't scrog any loops going
+	 * on in the main program.  We save the necessary info in variables
+	 * local to this function so that function nesting works OK.
+	 * We also only bother to save the loop stuff if we're in a loop
+	 * when the function is called.
+	 */
+	if (loop_tag_valid) {
+		int junk = 0;
+
+		save_loop_tag_valid = (volatile int) loop_tag_valid;
+		PUSH_BINDING(loop_tag_stack, loop_tag, junk);
+		loop_tag_valid = 0;
+	}
+	save_stack = stack_ptr;
+	stack_ptr = local_stack;
+	PUSH_BINDING(func_tag_stack, func_tag, func_tag_valid);
+	save_ret_node = ret_node;
+	ret_node = Nnull_string;	/* default return value */
+	if (setjmp(func_tag) == 0)
+		(void) interpret(f->rnode);
+
+	r = ret_node;
+	ret_node = (NODE *) save_ret_node;
+	RESTORE_BINDING(func_tag_stack, func_tag, func_tag_valid);
+	stack_ptr = (NODE **) save_stack;
+
+	/*
+	 * here, we pop each parameter and check whether
+	 * it was an array.  If so, and if the arg. passed in was
+	 * a simple variable, then the value should be copied back.
+	 * This achieves "call-by-reference" for arrays.
+	 */
+	sp = local_stack;
+	count = f->lnode->param_cnt;
+	for (argp = arg_list; count > 0 && argp != NULL; argp = argp->rnode) {
+		arg = argp->lnode;
+		if (arg->type == Node_param_list)
+			arg = stack_ptr[arg->param_cnt];
+		n = *sp++;
+		if (arg->type == Node_var && n->type == Node_var_array) {
+			/* should we free arg->var_value ? */
+			arg->var_array = n->var_array;
+			arg->type = Node_var_array;
+		}
+		unref(n->lnode);
+		freenode(n);
+		count--;
+	}
+	while (count-- > 0) {
+		n = *sp++;
+		/* if n is an (local) array, all the elements should be freed */
+		if (n->type == Node_var_array) {
+			assoc_clear(n);
+			free(n->var_array);
+		}
+		unref(n->lnode);
+		freenode(n);
+	}
+	if (local_stack)
+		free((char *) local_stack);
+
+	/* Restore the loop_tag stuff if necessary. */
+	if (save_loop_tag_valid) {
+		int junk = 0;
+
+		loop_tag_valid = (int) save_loop_tag_valid;
+		RESTORE_BINDING(loop_tag_stack, loop_tag, junk);
+	}
+
+	if (!(r->flags & PERM))
+		r->flags |= TEMP;
+	return r;
+}
+
+/*
+ * This returns a POINTER to a node pointer. get_lhs(ptr) is the current
+ * value of the var, or where to store the var's new value 
+ */
+
+NODE **
+get_lhs(ptr, assign)
+register NODE *ptr;
+Func_ptr *assign;
+{
+	register NODE **aptr = NULL;
+	register NODE *n;
+
+	switch (ptr->type) {
+	case Node_var_array:
+		fatal("attempt to use an array in a scalar context");
+	case Node_var:
+		aptr = &(ptr->var_value);
+#ifdef DEBUG
+		if (ptr->var_value->stref <= 0)
+			cant_happen();
+#endif
+		break;
+
+	case Node_FIELDWIDTHS:
+		aptr = &(FIELDWIDTHS_node->var_value);
+		if (assign)
+			*assign = set_FIELDWIDTHS;
+		break;
+
+	case Node_RS:
+		aptr = &(RS_node->var_value);
+		if (assign)
+			*assign = set_RS;
+		break;
+
+	case Node_FS:
+		aptr = &(FS_node->var_value);
+		if (assign)
+			*assign = set_FS;
+		break;
+
+	case Node_FNR:
+		unref(FNR_node->var_value);
+		FNR_node->var_value = make_number((AWKNUM) FNR);
+		aptr = &(FNR_node->var_value);
+		if (assign)
+			*assign = set_FNR;
+		break;
+
+	case Node_NR:
+		unref(NR_node->var_value);
+		NR_node->var_value = make_number((AWKNUM) NR);
+		aptr = &(NR_node->var_value);
+		if (assign)
+			*assign = set_NR;
+		break;
+
+	case Node_NF:
+		if (NF == -1)
+			(void) get_field(HUGE-1, assign); /* parse record */
+		unref(NF_node->var_value);
+		NF_node->var_value = make_number((AWKNUM) NF);
+		aptr = &(NF_node->var_value);
+		if (assign)
+			*assign = set_NF;
+		break;
+
+	case Node_IGNORECASE:
+		unref(IGNORECASE_node->var_value);
+		IGNORECASE_node->var_value = make_number((AWKNUM) IGNORECASE);
+		aptr = &(IGNORECASE_node->var_value);
+		if (assign)
+			*assign = set_IGNORECASE;
+		break;
+
+	case Node_OFMT:
+		aptr = &(OFMT_node->var_value);
+		if (assign)
+			*assign = set_OFMT;
+		break;
+
+	case Node_CONVFMT:
+		aptr = &(CONVFMT_node->var_value);
+		if (assign)
+			*assign = set_CONVFMT;
+		break;
+
+	case Node_ORS:
+		aptr = &(ORS_node->var_value);
+		if (assign)
+			*assign = set_ORS;
+		break;
+
+	case Node_OFS:
+		aptr = &(OFS_node->var_value);
+		if (assign)
+			*assign = set_OFS;
+		break;
+
+	case Node_param_list:
+		aptr = &(stack_ptr[ptr->param_cnt]->var_value);
+		break;
+
+	case Node_field_spec:
+		{
+		int field_num;
+
+		n = tree_eval(ptr->lnode);
+		field_num = (int) force_number(n);
+		free_temp(n);
+		if (field_num < 0)
+			fatal("attempt to access field %d", field_num);
+		if (field_num == 0 && field0_valid) {	/* short circuit */
+			aptr = &fields_arr[0];
+			if (assign)
+				*assign = reset_record;
+			break;
+		}
+		aptr = get_field(field_num, assign);
+		break;
+		}
+	case Node_subscript:
+		n = ptr->lnode;
+		if (n->type == Node_param_list)
+			n = stack_ptr[n->param_cnt];
+		aptr = assoc_lookup(n, concat_exp(ptr->rnode));
+		break;
+
+	case Node_func:
+		fatal ("`%s' is a function, assignment is not allowed",
+			ptr->lnode->param);
+	default:
+		cant_happen();
+	}
+	return aptr;
+}
+
+static NODE *
+match_op(tree)
+register NODE *tree;
+{
+	register NODE *t1;
+	register Regexp *rp;
+	int i;
+	int match = 1;
+
+	if (tree->type == Node_nomatch)
+		match = 0;
+	if (tree->type == Node_regex)
+		t1 = *get_field(0, (Func_ptr *) 0);
+	else {
+		t1 = force_string(tree_eval(tree->lnode));
+		tree = tree->rnode;
+	}
+	rp = re_update(tree);
+	i = research(rp, t1->stptr, 0, t1->stlen, 0);
+	i = (i == -1) ^ (match == 1);
+	free_temp(t1);
+	return tmp_number((AWKNUM) i);
+}
+
+void
+set_IGNORECASE()
+{
+	static int warned = 0;
+
+	if ((do_lint || do_unix) && ! warned) {
+		warned = 1;
+		warning("IGNORECASE not supported in compatibility mode");
+	}
+	IGNORECASE = (force_number(IGNORECASE_node->var_value) != 0.0);
+	set_FS();
+}
+
+void
+set_OFS()
+{
+	OFS = force_string(OFS_node->var_value)->stptr;
+	OFSlen = OFS_node->var_value->stlen;
+	OFS[OFSlen] = '\0';
+}
+
+void
+set_ORS()
+{
+	ORS = force_string(ORS_node->var_value)->stptr;
+	ORSlen = ORS_node->var_value->stlen;
+	ORS[ORSlen] = '\0';
+}
+
+static NODE **fmt_list = NULL;
+static int fmt_ok P((NODE *n));
+static int fmt_index P((NODE *n));
+
+static int
+fmt_ok(n)
+NODE *n;
+{
+	/* to be done later */
+	return 1;
+}
+
+static int
+fmt_index(n)
+NODE *n;
+{
+	register int ix = 0;
+	static int fmt_num = 4;
+	static int fmt_hiwater = 0;
+
+	if (fmt_list == NULL)
+		emalloc(fmt_list, NODE **, fmt_num*sizeof(*fmt_list), "fmt_index");
+	(void) force_string(n);
+	while (ix < fmt_hiwater) {
+		if (cmp_nodes(fmt_list[ix], n) == 0)
+			return ix;
+		ix++;
+	}
+	/* not found */
+	n->stptr[n->stlen] = '\0';
+	if (!fmt_ok(n))
+		warning("bad FMT specification");
+	if (fmt_hiwater >= fmt_num) {
+		fmt_num *= 2;
+		emalloc(fmt_list, NODE **, fmt_num, "fmt_index");
+	}
+	fmt_list[fmt_hiwater] = dupnode(n);
+	return fmt_hiwater++;
+}
+
+void
+set_OFMT()
+{
+	OFMTidx = fmt_index(OFMT_node->var_value);
+	OFMT = fmt_list[OFMTidx]->stptr;
+}
+
+void
+set_CONVFMT()
+{
+	CONVFMTidx = fmt_index(CONVFMT_node->var_value);
+	CONVFMT = fmt_list[CONVFMTidx]->stptr;
+}
diff --git a/gnu/usr.bin/awk/field.c b/gnu/usr.bin/awk/field.c
new file mode 100644
index 000000000000..d8f9a5455631
--- /dev/null
+++ b/gnu/usr.bin/awk/field.c
@@ -0,0 +1,645 @@
+/*
+ * field.c - routines for dealing with fields and record parsing
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "awk.h"
+
+static int (*parse_field) P((int, char **, int, NODE *,
+			     Regexp *, void (*)(), NODE *));
+static void rebuild_record P((void));
+static int re_parse_field P((int, char **, int, NODE *,
+			     Regexp *, void (*)(), NODE *));
+static int def_parse_field P((int, char **, int, NODE *,
+			      Regexp *, void (*)(), NODE *));
+static int sc_parse_field P((int, char **, int, NODE *,
+			     Regexp *, void (*)(), NODE *));
+static int fw_parse_field P((int, char **, int, NODE *,
+			     Regexp *, void (*)(), NODE *));
+static void set_element P((int, char *, int, NODE *));
+static void grow_fields_arr P((int num));
+static void set_field P((int num, char *str, int len, NODE *dummy));
+
+
+static Regexp *FS_regexp = NULL;
+static char *parse_extent;	/* marks where to restart parse of record */
+static int parse_high_water=0;	/* field number that we have parsed so far */
+static int nf_high_water = 0;	/* size of fields_arr */
+static int resave_fs;
+static NODE *save_FS;		/* save current value of FS when line is read,
+				 * to be used in deferred parsing
+				 */
+
+NODE **fields_arr;		/* array of pointers to the field nodes */
+int field0_valid;		/* $(>0) has not been changed yet */
+int default_FS;
+static NODE **nodes;		/* permanent repository of field nodes */
+static int *FIELDWIDTHS = NULL;
+
+void
+init_fields()
+{
+	NODE *n;
+
+	emalloc(fields_arr, NODE **, sizeof(NODE *), "init_fields");
+	emalloc(nodes, NODE **, sizeof(NODE *), "init_fields");
+	getnode(n);
+	*n = *Nnull_string;
+	fields_arr[0] = nodes[0] = n;
+	parse_extent = fields_arr[0]->stptr;
+	save_FS = dupnode(FS_node->var_value);
+	field0_valid = 1;
+}
+
+
+static void
+grow_fields_arr(num)
+int num;
+{
+	register int t;
+	register NODE *n;
+
+	erealloc(fields_arr, NODE **, (num + 1) * sizeof(NODE *), "set_field");
+	erealloc(nodes, NODE **, (num+1) * sizeof(NODE *), "set_field");
+	for (t = nf_high_water+1; t <= num; t++) {
+		getnode(n);
+		*n = *Nnull_string;
+		fields_arr[t] = nodes[t] = n;
+	}
+	nf_high_water = num;
+}
+
+/*ARGSUSED*/
+static void
+set_field(num, str, len, dummy)
+int num;
+char *str;
+int len;
+NODE *dummy;	/* not used -- just to make interface same as set_element */
+{
+	register NODE *n;
+
+	if (num > nf_high_water)
+		grow_fields_arr(num);
+	n = nodes[num];
+	n->stptr = str;
+	n->stlen = len;
+	n->flags = (PERM|STR|STRING|MAYBE_NUM);
+	fields_arr[num] = n;
+}
+
+/* Someone assigned a value to $(something).  Fix up $0 to be right */
+static void
+rebuild_record()
+{
+	register int tlen;
+	register NODE *tmp;
+	NODE *ofs;
+	char *ops;
+	register char *cops;
+	register NODE **ptr;
+	register int ofslen;
+
+	tlen = 0;
+	ofs = force_string(OFS_node->var_value);
+	ofslen = ofs->stlen;
+	ptr = &fields_arr[NF];
+	while (ptr > &fields_arr[0]) {
+		tmp = force_string(*ptr);
+		tlen += tmp->stlen;
+		ptr--;
+	}
+	tlen += (NF - 1) * ofslen;
+	if (tlen < 0)
+	    tlen = 0;
+	emalloc(ops, char *, tlen + 2, "fix_fields");
+	cops = ops;
+	ops[0] = '\0';
+	for (ptr = &fields_arr[1]; ptr <= &fields_arr[NF]; ptr++) {
+		tmp = *ptr;
+		if (tmp->stlen == 1)
+			*cops++ = tmp->stptr[0];
+		else if (tmp->stlen != 0) {
+			memcpy(cops, tmp->stptr, tmp->stlen);
+			cops += tmp->stlen;
+		}
+		if (ptr != &fields_arr[NF]) {
+			if (ofslen == 1)
+				*cops++ = ofs->stptr[0];
+			else if (ofslen != 0) {
+				memcpy(cops, ofs->stptr, ofslen);
+				cops += ofslen;
+			}
+		}
+	}
+	tmp = make_str_node(ops, tlen, ALREADY_MALLOCED);
+	unref(fields_arr[0]);
+	fields_arr[0] = tmp;
+	field0_valid = 1;
+}
+
+/*
+ * setup $0, but defer parsing rest of line until reference is made to $(>0)
+ * or to NF.  At that point, parse only as much as necessary.
+ */
+void
+set_record(buf, cnt, freeold)
+char *buf;
+int cnt;
+int freeold;
+{
+	register int i;
+
+	NF = -1;
+	for (i = 1; i <= parse_high_water; i++) {
+		unref(fields_arr[i]);
+	}
+	parse_high_water = 0;
+	if (freeold) {
+		unref(fields_arr[0]);
+		if (resave_fs) {
+			resave_fs = 0;
+			unref(save_FS);
+			save_FS = dupnode(FS_node->var_value);
+		}
+		nodes[0]->stptr = buf;
+		nodes[0]->stlen = cnt;
+		nodes[0]->stref = 1;
+		nodes[0]->flags = (STRING|STR|PERM|MAYBE_NUM);
+		fields_arr[0] = nodes[0];
+	}
+	fields_arr[0]->flags |= MAYBE_NUM;
+	field0_valid = 1;
+}
+
+void
+reset_record()
+{
+	(void) force_string(fields_arr[0]);
+	set_record(fields_arr[0]->stptr, fields_arr[0]->stlen, 0);
+}
+
+void
+set_NF()
+{
+	register int i;
+
+	NF = (int) force_number(NF_node->var_value);
+	if (NF > nf_high_water)
+		grow_fields_arr(NF);
+	for (i = parse_high_water + 1; i <= NF; i++) {
+		unref(fields_arr[i]);
+		fields_arr[i] = Nnull_string;
+	}
+	field0_valid = 0;
+}
+
+/*
+ * this is called both from get_field() and from do_split()
+ * via (*parse_field)().  This variation is for when FS is a regular
+ * expression -- either user-defined or because RS=="" and FS==" "
+ */
+static int
+re_parse_field(up_to, buf, len, fs, rp, set, n)
+int up_to;	/* parse only up to this field number */
+char **buf;	/* on input: string to parse; on output: point to start next */
+int len;
+NODE *fs;
+Regexp *rp;
+void (*set) ();	/* routine to set the value of the parsed field */
+NODE *n;
+{
+	register char *scan = *buf;
+	register int nf = parse_high_water;
+	register char *field;
+	register char *end = scan + len;
+
+	if (up_to == HUGE)
+		nf = 0;
+	if (len == 0)
+		return nf;
+
+	if (*RS == 0 && default_FS)
+		while (scan < end && isspace(*scan))
+			scan++;
+	field = scan;
+	while (scan < end
+	       && research(rp, scan, 0, (int)(end - scan), 1) != -1
+	       && nf < up_to) {
+		if (REEND(rp, scan) == RESTART(rp, scan)) {	/* null match */
+			scan++;
+			if (scan == end) {
+				(*set)(++nf, field, scan - field, n);
+				up_to = nf;
+				break;
+			}
+			continue;
+		}
+		(*set)(++nf, field, scan + RESTART(rp, scan) - field, n);
+		scan += REEND(rp, scan);
+		field = scan;
+		if (scan == end)	/* FS at end of record */
+			(*set)(++nf, field, 0, n);
+	}
+	if (nf != up_to && scan < end) {
+		(*set)(++nf, scan, (int)(end - scan), n);
+		scan = end;
+	}
+	*buf = scan;
+	return (nf);
+}
+
+/*
+ * this is called both from get_field() and from do_split()
+ * via (*parse_field)().  This variation is for when FS is a single space
+ * character.
+ */
+static int
+def_parse_field(up_to, buf, len, fs, rp, set, n)
+int up_to;	/* parse only up to this field number */
+char **buf;	/* on input: string to parse; on output: point to start next */
+int len;
+NODE *fs;
+Regexp *rp;
+void (*set) ();	/* routine to set the value of the parsed field */
+NODE *n;
+{
+	register char *scan = *buf;
+	register int nf = parse_high_water;
+	register char *field;
+	register char *end = scan + len;
+	char sav;
+
+	if (up_to == HUGE)
+		nf = 0;
+	if (len == 0)
+		return nf;
+
+	/* before doing anything save the char at *end */
+	sav = *end;
+	/* because it will be destroyed now: */
+
+	*end = ' ';	/* sentinel character */
+	for (; nf < up_to; scan++) {
+		/*
+		 * special case:  fs is single space, strip leading whitespace 
+		 */
+		while (scan < end && (*scan == ' ' || *scan == '\t'))
+			scan++;
+		if (scan >= end)
+			break;
+		field = scan;
+		while (*scan != ' ' && *scan != '\t')
+			scan++;
+		(*set)(++nf, field, (int)(scan - field), n);
+		if (scan == end)
+			break;
+	}
+
+	/* everything done, restore original char at *end */
+	*end = sav;
+
+	*buf = scan;
+	return nf;
+}
+
+/*
+ * this is called both from get_field() and from do_split()
+ * via (*parse_field)().  This variation is for when FS is a single character
+ * other than space.
+ */
+static int
+sc_parse_field(up_to, buf, len, fs, rp, set, n)
+int up_to;	/* parse only up to this field number */
+char **buf;	/* on input: string to parse; on output: point to start next */
+int len;
+NODE *fs;
+Regexp *rp;
+void (*set) ();	/* routine to set the value of the parsed field */
+NODE *n;
+{
+	register char *scan = *buf;
+	register char fschar;
+	register int nf = parse_high_water;
+	register char *field;
+	register char *end = scan + len;
+	char sav;
+
+	if (up_to == HUGE)
+		nf = 0;
+	if (len == 0)
+		return nf;
+
+	if (*RS == 0 && fs->stlen == 0)
+		fschar = '\n';
+	else
+		fschar = fs->stptr[0];
+
+	/* before doing anything save the char at *end */
+	sav = *end;
+	/* because it will be destroyed now: */
+	*end = fschar;	/* sentinel character */
+
+	for (; nf < up_to; scan++) {
+		field = scan;
+		while (*scan++ != fschar)
+			;
+		scan--;
+		(*set)(++nf, field, (int)(scan - field), n);
+		if (scan == end)
+			break;
+	}
+
+	/* everything done, restore original char at *end */
+	*end = sav;
+
+	*buf = scan;
+	return nf;
+}
+
+/*
+ * this is called both from get_field() and from do_split()
+ * via (*parse_field)().  This variation is for fields are fixed widths.
+ */
+static int
+fw_parse_field(up_to, buf, len, fs, rp, set, n)
+int up_to;	/* parse only up to this field number */
+char **buf;	/* on input: string to parse; on output: point to start next */
+int len;
+NODE *fs;
+Regexp *rp;
+void (*set) ();	/* routine to set the value of the parsed field */
+NODE *n;
+{
+	register char *scan = *buf;
+	register int nf = parse_high_water;
+	register char *end = scan + len;
+
+	if (up_to == HUGE)
+		nf = 0;
+	if (len == 0)
+		return nf;
+	for (; nf < up_to && (len = FIELDWIDTHS[nf+1]) != -1; ) {
+		if (len > end - scan)
+			len = end - scan;
+		(*set)(++nf, scan, len, n);
+		scan += len;
+	}
+	if (len == -1)
+		*buf = end;
+	else
+		*buf = scan;
+	return nf;
+}
+
+NODE **
+get_field(requested, assign)
+register int requested;
+Func_ptr *assign;	/* this field is on the LHS of an assign */
+{
+	/*
+	 * if requesting whole line but some other field has been altered,
+	 * then the whole line must be rebuilt
+	 */
+	if (requested == 0) {
+		if (!field0_valid) {
+			/* first, parse remainder of input record */
+			if (NF == -1) {
+				NF = (*parse_field)(HUGE-1, &parse_extent,
+		    			fields_arr[0]->stlen -
+					(parse_extent - fields_arr[0]->stptr),
+		    			save_FS, FS_regexp, set_field,
+					(NODE *)NULL);
+				parse_high_water = NF;
+			}
+			rebuild_record();
+		}
+		if (assign)
+			*assign = reset_record;
+		return &fields_arr[0];
+	}
+
+	/* assert(requested > 0); */
+
+	if (assign)
+		field0_valid = 0;		/* $0 needs reconstruction */
+
+	if (requested <= parse_high_water)	/* already parsed this field */
+		return &fields_arr[requested];
+
+	if (NF == -1) {	/* have not yet parsed to end of record */
+		/*
+		 * parse up to requested fields, calling set_field() for each,
+		 * saving in parse_extent the point where the parse left off
+		 */
+		if (parse_high_water == 0)	/* starting at the beginning */
+			parse_extent = fields_arr[0]->stptr;
+		parse_high_water = (*parse_field)(requested, &parse_extent,
+		     fields_arr[0]->stlen - (parse_extent-fields_arr[0]->stptr),
+		     save_FS, FS_regexp, set_field, (NODE *)NULL);
+
+		/*
+		 * if we reached the end of the record, set NF to the number of 
+		 * fields so far.  Note that requested might actually refer to
+		 * a field that is beyond the end of the record, but we won't
+		 * set NF to that value at this point, since this is only a
+		 * reference to the field and NF only gets set if the field
+		 * is assigned to -- this case is handled below
+		 */
+		if (parse_extent == fields_arr[0]->stptr + fields_arr[0]->stlen)
+			NF = parse_high_water;
+		if (requested == HUGE-1)	/* HUGE-1 means set NF */
+			requested = parse_high_water;
+	}
+	if (parse_high_water < requested) { /* requested beyond end of record */
+		if (assign) {	/* expand record */
+			register int i;
+
+			if (requested > nf_high_water)
+				grow_fields_arr(requested);
+
+			/* fill in fields that don't exist */
+			for (i = parse_high_water + 1; i <= requested; i++)
+				fields_arr[i] = Nnull_string;
+
+			NF = requested;
+			parse_high_water = requested;
+		} else
+			return &Nnull_string;
+	}
+
+	return &fields_arr[requested];
+}
+
+static void
+set_element(num, s, len, n)
+int num;
+char *s;
+int len;
+NODE *n;
+{
+	register NODE *it;
+
+	it = make_string(s, len);
+	it->flags |= MAYBE_NUM;
+	*assoc_lookup(n, tmp_number((AWKNUM) (num))) = it;
+}
+
+NODE *
+do_split(tree)
+NODE *tree;
+{
+	NODE *t1, *t2, *t3, *tmp;
+	NODE *fs;
+	char *s;
+	int (*parseit)P((int, char **, int, NODE *,
+			 Regexp *, void (*)(), NODE *));
+	Regexp *rp = NULL;
+
+	t1 = tree_eval(tree->lnode);
+	t2 = tree->rnode->lnode;
+	t3 = tree->rnode->rnode->lnode;
+
+	(void) force_string(t1);
+
+	if (t2->type == Node_param_list)
+		t2 = stack_ptr[t2->param_cnt];
+	if (t2->type != Node_var && t2->type != Node_var_array)
+		fatal("second argument of split is not a variable");
+	assoc_clear(t2);
+
+	if (t3->re_flags & FS_DFLT) {
+		parseit = parse_field;
+		fs = force_string(FS_node->var_value);
+		rp = FS_regexp;
+	} else {
+		tmp = force_string(tree_eval(t3->re_exp));
+		if (tmp->stlen == 1) {
+			if (tmp->stptr[0] == ' ')
+				parseit = def_parse_field;
+			else
+				parseit = sc_parse_field;
+		} else {
+			parseit = re_parse_field;
+			rp = re_update(t3);
+		}
+		fs = tmp;
+	}
+
+	s = t1->stptr;
+	tmp = tmp_number((AWKNUM) (*parseit)(HUGE, &s, (int)t1->stlen,
+					     fs, rp, set_element, t2));
+	free_temp(t1);
+	free_temp(t3);
+	return tmp;
+}
+
+void
+set_FS()
+{
+	NODE *tmp = NULL;
+	char buf[10];
+	NODE *fs;
+
+	buf[0] = '\0';
+	default_FS = 0;
+	if (FS_regexp) {
+		refree(FS_regexp);
+		FS_regexp = NULL;
+	}
+	fs = force_string(FS_node->var_value);
+	if (fs->stlen > 1)
+		parse_field = re_parse_field;
+	else if (*RS == 0) {
+		parse_field = sc_parse_field;
+		if (fs->stlen == 1) {
+			if (fs->stptr[0] == ' ') {
+				default_FS = 1;
+				strcpy(buf, "[ \t\n]+");
+			} else if (fs->stptr[0] != '\n')
+				sprintf(buf, "[%c\n]", fs->stptr[0]);
+		}
+	} else {
+		parse_field = def_parse_field;
+		if (fs->stptr[0] == ' ' && fs->stlen == 1)
+			default_FS = 1;
+		else if (fs->stptr[0] != ' ' && fs->stlen == 1) {
+			if (IGNORECASE == 0)
+				parse_field = sc_parse_field;
+			else
+				sprintf(buf, "[%c]", fs->stptr[0]);
+		}
+	}
+	if (buf[0]) {
+		FS_regexp = make_regexp(buf, strlen(buf), IGNORECASE, 1);
+		parse_field = re_parse_field;
+	} else if (parse_field == re_parse_field) {
+		FS_regexp = make_regexp(fs->stptr, fs->stlen, IGNORECASE, 1);
+	} else
+		FS_regexp = NULL;
+	resave_fs = 1;
+}
+
+void
+set_RS()
+{
+	(void) force_string(RS_node->var_value);
+	RS = RS_node->var_value->stptr;
+	set_FS();
+}
+
+void
+set_FIELDWIDTHS()
+{
+	register char *scan;
+	char *end;
+	register int i;
+	static int fw_alloc = 1;
+	static int warned = 0;
+	extern double strtod();
+
+	if (do_lint && ! warned) {
+		warned = 1;
+		warning("use of FIELDWIDTHS is a gawk extension");
+	}
+	if (do_unix)	/* quick and dirty, does the trick */
+		return;
+
+	parse_field = fw_parse_field;
+	scan = force_string(FIELDWIDTHS_node->var_value)->stptr;
+	end = scan + 1;
+	if (FIELDWIDTHS == NULL)
+		emalloc(FIELDWIDTHS, int *, fw_alloc * sizeof(int), "set_FIELDWIDTHS");
+	FIELDWIDTHS[0] = 0;
+	for (i = 1; ; i++) {
+		if (i >= fw_alloc) {
+			fw_alloc *= 2;
+			erealloc(FIELDWIDTHS, int *, fw_alloc * sizeof(int), "set_FIELDWIDTHS");
+		}
+		FIELDWIDTHS[i] = (int) strtod(scan, &end);
+		if (end == scan)
+			break;
+		scan = end;
+	}
+	FIELDWIDTHS[i] = -1;
+}
diff --git a/gnu/usr.bin/awk/gawk.texi b/gnu/usr.bin/awk/gawk.texi
new file mode 100644
index 000000000000..b2802623136d
--- /dev/null
+++ b/gnu/usr.bin/awk/gawk.texi
@@ -0,0 +1,11270 @@
+\input texinfo   @c -*-texinfo-*-
+@c %**start of header (This is for running Texinfo on a region.)
+@setfilename gawk.info
+@settitle The GAWK Manual
+@c @smallbook
+@c %**end of header (This is for running Texinfo on a region.)
+
+@ifinfo
+@synindex fn cp
+@synindex vr cp
+@end ifinfo
+@iftex
+@syncodeindex fn cp
+@syncodeindex vr cp
+@end iftex
+
+@c If "finalout" is commented out, the printed output will show
+@c black boxes that mark lines that are too long.  Thus, it is
+@c unwise to comment it out when running a master in case there are
+@c overfulls which are deemed okay.
+
+@iftex
+@finalout
+@end iftex
+
+@c ===> NOTE! <==
+@c Determine the edition number in *four* places by hand:
+@c   1. First ifinfo section  2. title page  3. copyright page 4. top node
+@c To find the locations, search for !!set
+
+@ifinfo
+This file documents @code{awk}, a program that you can use to select
+particular records in a file and perform operations upon them.
+
+This is Edition 0.15 of @cite{The GAWK Manual}, @*
+for the 2.15 version of the GNU implementation @*
+of AWK.
+
+Copyright (C) 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
+
+Permission is granted to make and distribute verbatim copies of
+this manual provided the copyright notice and this permission notice
+are preserved on all copies.
+
+@ignore
+Permission is granted to process this file through TeX and print the
+results, provided the printed document carries copying permission
+notice identical to this one except for the removal of this paragraph
+(this paragraph not being relevant to the printed manual).
+
+@end ignore
+Permission is granted to copy and distribute modified versions of this
+manual under the conditions for verbatim copying, provided that the entire
+resulting derived work is distributed under the terms of a permission
+notice identical to this one.
+
+Permission is granted to copy and distribute translations of this manual
+into another language, under the above conditions for modified versions,
+except that this permission notice may be stated in a translation approved
+by the Foundation.
+@end ifinfo
+
+@setchapternewpage odd
+
+@c !!set edition, date, version
+@titlepage
+@title The GAWK Manual
+@subtitle Edition 0.15
+@subtitle April 1993
+@author Diane Barlow Close
+@author Arnold D. Robbins
+@author Paul H. Rubin
+@author Richard Stallman
+
+@c Include the Distribution inside the titlepage environment so
+@c that headings are turned off.  Headings on and off do not work.
+
+@page
+@vskip 0pt plus 1filll
+Copyright @copyright{} 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
+@sp 2
+        
+@c !!set edition, date, version
+This is Edition 0.15 of @cite{The GAWK Manual}, @*
+for the 2.15 version of the GNU implementation @*
+of AWK.
+
+@sp 2
+Published by the Free Software Foundation @*
+675 Massachusetts Avenue @*
+Cambridge, MA 02139 USA @*
+Printed copies are available for $20 each.
+
+Permission is granted to make and distribute verbatim copies of
+this manual provided the copyright notice and this permission notice
+are preserved on all copies.
+
+Permission is granted to copy and distribute modified versions of this
+manual under the conditions for verbatim copying, provided that the entire
+resulting derived work is distributed under the terms of a permission
+notice identical to this one.
+
+Permission is granted to copy and distribute translations of this manual
+into another language, under the above conditions for modified versions,
+except that this permission notice may be stated in a translation approved
+by the Foundation.
+@end titlepage
+
+@ifinfo
+@node Top, Preface, (dir), (dir)
+@comment  node-name,  next,  previous,  up
+@top General Introduction
+@c Preface or Licensing nodes should come right after the Top
+@c node, in `unnumbered' sections, then the chapter, `What is gawk'.
+
+This file documents @code{awk}, a program that you can use to select
+particular records in a file and perform operations upon them.
+
+@c !!set edition, date, version
+This is Edition 0.15 of @cite{The GAWK Manual}, @*
+for the 2.15 version of the GNU implementation @*
+of AWK.
+
+@end ifinfo
+
+@menu
+* Preface::                     What you can do with @code{awk}; brief history
+                                and acknowledgements.
+* Copying::                     Your right to copy and distribute @code{gawk}.
+* This Manual::                 Using this manual. 
+                                Includes sample input files that you can use.
+* Getting Started::             A basic introduction to using @code{awk}.
+                                How to run an @code{awk} program.  
+                                Command line syntax.
+* Reading Files::               How to read files and manipulate fields.
+* Printing::                    How to print using @code{awk}.  Describes the
+                                @code{print} and @code{printf} statements.  
+                                Also describes redirection of output.
+* One-liners::                  Short, sample @code{awk} programs.
+* Patterns::                    The various types of patterns 
+                                explained in detail.
+* Actions::                     The various types of actions are
+                                introduced here.  Describes
+                                expressions and the various operators in
+                                detail.  Also describes comparison expressions.
+* Expressions::                 Expressions are the basic building
+                                blocks of statements.
+* Statements::                  The various control statements are 
+                                described in detail.
+* Arrays::                      The description and use of arrays.  
+                                Also includes array-oriented control 
+                                statements.
+* Built-in::                    The built-in functions are summarized here.
+* User-defined::                User-defined functions are described in detail.
+* Built-in Variables::          Built-in Variables
+* Command Line::                How to run @code{gawk}.
+* Language History::            The evolution of the @code{awk} language.
+* Installation::                Installing @code{gawk} under 
+                                various operating systems.
+* Gawk Summary::                @code{gawk} Options and Language Summary.
+* Sample Program::              A sample @code{awk} program with a 
+                                complete explanation.
+* Bugs::                        Reporting Problems and Bugs.
+* Notes::                       Something about the 
+                                implementation of @code{gawk}.
+* Glossary::                    An explanation of some unfamiliar terms.
+* Index::                       
+@end menu
+
+@node Preface, Copying, Top, Top
+@comment  node-name,  next,  previous,  up
+@unnumbered Preface
+
+@iftex
+@cindex what is @code{awk}
+@end iftex
+If you are like many computer users, you would frequently like to make
+changes in various text files wherever certain patterns appear, or
+extract data from parts of certain lines while discarding the rest.  To
+write a program to do this in a language such as C or Pascal is a
+time-consuming inconvenience that may take many lines of code.  The job
+may be easier with @code{awk}.
+
+The @code{awk} utility interprets a special-purpose programming language
+that makes it possible to handle simple data-reformatting jobs easily
+with just a few lines of code.
+
+The GNU implementation of @code{awk} is called @code{gawk}; it is fully
+upward compatible with the System V Release 4 version of
+@code{awk}.  @code{gawk} is also upward compatible with the @sc{posix}
+(draft) specification of the @code{awk} language.  This means that all
+properly written @code{awk} programs should work with @code{gawk}.
+Thus, we usually don't distinguish between @code{gawk} and other @code{awk}
+implementations in this manual.@refill
+
+@cindex uses of @code{awk}
+This manual teaches you what @code{awk} does and how you can use
+@code{awk} effectively.  You should already be familiar with basic
+system commands such as @code{ls}.  Using @code{awk} you can: @refill
+
+@itemize @bullet
+@item
+manage small, personal databases
+
+@item
+generate reports
+
+@item
+validate data
+@item
+produce indexes, and perform other document preparation tasks
+
+@item
+even experiment with algorithms that can be adapted later to other computer
+languages
+@end itemize
+
+@iftex
+This manual has the difficult task of being both tutorial and reference.
+If you are a novice, feel free to skip over details that seem too complex.
+You should also ignore the many cross references; they are for the
+expert user, and for the on-line Info version of the manual.
+@end iftex
+
+@menu
+* History::                     The history of @code{gawk} and
+                                @code{awk}.  Acknowledgements.
+@end menu
+
+@node History,  , Preface, Preface
+@comment  node-name,  next,  previous,  up
+@unnumberedsec History of @code{awk} and @code{gawk}
+
+@cindex acronym
+@cindex history of @code{awk}
+The name @code{awk} comes from the initials of its designers: Alfred V.
+Aho, Peter J. Weinberger, and Brian W. Kernighan.  The original version of
+@code{awk} was written in 1977.  In 1985 a new version made the programming
+language more powerful, introducing user-defined functions, multiple input
+streams, and computed regular expressions.
+This new version became generally available with System V Release 3.1.
+The version in System V Release 4 added some new features and also cleaned
+up the behavior in some of the ``dark corners'' of the language.
+The specification for @code{awk} in the @sc{posix} Command Language
+and Utilities standard further clarified the language based on feedback
+from both the @code{gawk} designers, and the original @code{awk}
+designers.@refill
+
+The GNU implementation, @code{gawk}, was written in 1986 by Paul Rubin
+and Jay Fenlason, with advice from Richard Stallman.  John Woods
+contributed parts of the code as well.  In 1988 and 1989, David Trueman, with
+help from Arnold Robbins, thoroughly reworked @code{gawk} for compatibility
+with the newer @code{awk}.  Current development (1992) focuses on bug fixes,
+performance improvements, and standards compliance.
+
+We need to thank many people for their assistance in producing this
+manual.  Jay Fenlason contributed many ideas and sample programs.  Richard
+Mlynarik and Robert J. Chassell gave helpful comments on early drafts of this
+manual.  The paper @cite{A Supplemental Document for @code{awk}} by John W.
+Pierce of the Chemistry Department at UC San Diego, pinpointed several
+issues relevant both to @code{awk} implementation and to this manual, that
+would otherwise have escaped us.  David Trueman, Pat Rankin, and Michal
+Jaegermann also contributed sections of the manual.@refill
+
+The following people provided many helpful comments on this edition of
+the manual: Rick Adams, Michael Brennan, Rich Burridge, Diane Close,
+Christopher (``Topher'') Eliot, Michael Lijewski, Pat Rankin, Miriam Robbins,
+and Michal Jaegermann.  Robert J. Chassell provided much valuable advice on
+the use of Texinfo.
+
+Finally, we would like to thank Brian Kernighan of Bell Labs for invaluable
+assistance during the testing and debugging of @code{gawk}, and for
+help in clarifying numerous points about the language.@refill
+
+@node Copying, This Manual, Preface, Top
+@unnumbered GNU GENERAL PUBLIC LICENSE
+@center Version 2, June 1991
+
+@display
+Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
+675 Mass Ave, Cambridge, MA 02139, USA
+
+Everyone is permitted to copy and distribute verbatim copies
+of this license document, but changing it is not allowed.
+@end display
+
+@c fakenode --- for prepinfo
+@unnumberedsec Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software---to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+@iftex
+@c fakenode --- for prepinfo
+@unnumberedsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+@end iftex
+@ifinfo
+@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+@end ifinfo
+
+@enumerate
+@item
+This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The ``Program'', below,
+refers to any such program or work, and a ``work based on the Program''
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term ``modification''.)  Each licensee is addressed as ``you''.
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+@item
+You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+@item
+You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+@enumerate a
+@item
+You must cause the modified files to carry prominent notices
+stating that you changed the files and the date of any change.
+
+@item
+You must cause any work that you distribute or publish, that in
+whole or in part contains or is derived from the Program or any
+part thereof, to be licensed as a whole at no charge to all third
+parties under the terms of this License.
+
+@item
+If the modified program normally reads commands interactively
+when run, you must cause it, when started running for such
+interactive use in the most ordinary way, to print or display an
+announcement including an appropriate copyright notice and a
+notice that there is no warranty (or else, saying that you provide
+a warranty) and that users may redistribute the program under
+these conditions, and telling the user how to view a copy of this
+License.  (Exception: if the Program itself is interactive but
+does not normally print such an announcement, your work based on
+the Program is not required to print an announcement.)
+@end enumerate
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+@item
+You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+@enumerate a
+@item
+Accompany it with the complete corresponding machine-readable
+source code, which must be distributed under the terms of Sections
+1 and 2 above on a medium customarily used for software interchange; or,
+
+@item
+Accompany it with a written offer, valid for at least three
+years, to give any third party, for a charge no more than your
+cost of physically performing source distribution, a complete
+machine-readable copy of the corresponding source code, to be
+distributed under the terms of Sections 1 and 2 above on a medium
+customarily used for software interchange; or,
+
+@item
+Accompany it with the information you received as to the offer
+to distribute corresponding source code.  (This alternative is
+allowed only for noncommercial distribution and only if you
+received the program in object code or executable form with such
+an offer, in accord with Subsection b above.)
+@end enumerate
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+@item
+You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+@item
+You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+@item
+Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+@item
+If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+@item
+If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+@item
+The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and ``any
+later version'', you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+@item
+If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+@iftex
+@c fakenode --- for prepinfo
+@heading NO WARRANTY
+@end iftex
+@ifinfo
+@center NO WARRANTY
+@end ifinfo
+
+@item
+BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+@item
+IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+@end enumerate
+
+@iftex
+@c fakenode --- for prepinfo
+@heading END OF TERMS AND CONDITIONS
+@end iftex
+@ifinfo
+@center END OF TERMS AND CONDITIONS
+@end ifinfo
+
+@page
+@c fakenode --- for prepinfo
+@unnumberedsec How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the ``copyright'' line and a pointer to where the full notice is found.
+
+@smallexample
+@var{one line to give the program's name and a brief idea of what it does.}
+Copyright (C) 19@var{yy}  @var{name of author}
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+@end smallexample
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+@smallexample
+Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author}
+Gnomovision comes with ABSOLUTELY NO WARRANTY; for details 
+type `show w'.
+This is free software, and you are welcome to redistribute it
+under certain conditions; type `show c' for details.
+@end smallexample
+
+The hypothetical commands @samp{show w} and @samp{show c} should show
+the appropriate parts of the General Public License.  Of course, the
+commands you use may be called something other than @samp{show w} and
+@samp{show c}; they could even be mouse-clicks or menu items---whatever
+suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a ``copyright disclaimer'' for the program, if
+necessary.  Here is a sample; alter the names:
+
+@smallexample
+Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+`Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+@var{signature of Ty Coon}, 1 April 1989
+Ty Coon, President of Vice
+@end smallexample
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.
+
+@node This Manual, Getting Started, Copying, Top
+@chapter Using this Manual
+@cindex manual, using this
+@cindex using this manual
+@cindex language, @code{awk}
+@cindex program, @code{awk}
+@cindex @code{awk} language
+@cindex @code{awk} program
+
+The term @code{awk} refers to a particular program, and to the language you
+use to tell this program what to do.  When we need to be careful, we call
+the program ``the @code{awk} utility'' and the language ``the @code{awk}
+language.''  The term @code{gawk} refers to a version of @code{awk} developed
+as part the GNU project.  The purpose of this manual is to explain
+both the
+@code{awk} language and how to run the @code{awk} utility.@refill
+
+While concentrating on the features of @code{gawk}, the manual will also
+attempt to describe important differences between @code{gawk} and other
+@code{awk} implementations.  In particular, any features that are not
+in the @sc{posix} standard for @code{awk} will be noted.  @refill
+
+The term @dfn{@code{awk} program} refers to a program written by you in
+the @code{awk} programming language.@refill
+
+@xref{Getting Started, ,Getting Started with @code{awk}}, for the bare
+essentials you need to know to start using @code{awk}.  
+
+Some useful ``one-liners'' are included to give you a feel for the
+@code{awk} language (@pxref{One-liners, ,Useful ``One-liners''}).
+
+@ignore
+@strong{I deleted four paragraphs here because they would confuse the
+beginner more than help him.  They mention terms such as ``field,''
+``pattern,'' ``action,'' ``built-in function'' which the beginner
+doesn't know.}
+
+@strong{If you can find a way to introduce several of these concepts here,
+enough to give the reader a map of what is to follow, that might
+be useful.  I'm not sure that can be done without taking up more
+space than ought to be used here.  There may be no way to win.}
+
+@strong{ADR: I'd like to tackle this in phase 2 of my editing.}
+@end ignore
+
+A sample @code{awk} program has been provided for you
+(@pxref{Sample Program}).@refill
+
+If you find terms that you aren't familiar with, try looking them
+up in the glossary (@pxref{Glossary}).@refill
+
+The entire @code{awk} language is summarized for quick reference in
+@ref{Gawk Summary, ,@code{gawk} Summary}.  Look there if you just need
+to refresh your memory about a particular feature.@refill
+
+Most of the time complete @code{awk} programs are used as examples, but in
+some of the more advanced sections, only the part of the @code{awk} program
+that illustrates the concept being described is shown.@refill
+
+@menu
+* Sample Data Files::           Sample data files for use in the @code{awk} 
+                                programs illustrated in this manual.
+@end menu
+
+@node Sample Data Files,  , This Manual, This Manual
+@section Data Files for the Examples
+
+@cindex input file, sample
+@cindex sample input file
+@cindex @file{BBS-list} file
+Many of the examples in this manual take their input from two sample
+data files.  The first, called @file{BBS-list}, represents a list of
+computer bulletin board systems together with information about those systems.
+The second data file, called @file{inventory-shipped}, contains
+information about shipments on a monthly basis.  Each line of these
+files is one @dfn{record}.
+
+In the file @file{BBS-list}, each record contains the name of a computer
+bulletin board, its phone number, the board's baud rate, and a code for
+the number of hours it is operational.  An @samp{A} in the last column
+means the board operates 24 hours a day.  A @samp{B} in the last
+column means the board operates evening and weekend hours, only.  A
+@samp{C} means the board operates only on weekends.
+
+@example
+aardvark     555-5553     1200/300          B
+alpo-net     555-3412     2400/1200/300     A
+barfly       555-7685     1200/300          A
+bites        555-1675     2400/1200/300     A
+camelot      555-0542     300               C
+core         555-2912     1200/300          C
+fooey        555-1234     2400/1200/300     B
+foot         555-6699     1200/300          B
+macfoo       555-6480     1200/300          A
+sdace        555-3430     2400/1200/300     A
+sabafoo      555-2127     1200/300          C
+@end example
+
+@cindex @file{inventory-shipped} file
+The second data file, called @file{inventory-shipped}, represents
+information about shipments during the year.  
+Each record contains the month of the year, the number
+of green crates shipped, the number of red boxes shipped, the number of
+orange bags shipped, and the number of blue packages shipped,
+respectively.  There are 16 entries, covering the 12 months of one year
+and 4 months of the next year.@refill
+
+@example
+Jan  13  25  15 115
+Feb  15  32  24 226
+Mar  15  24  34 228
+Apr  31  52  63 420
+May  16  34  29 208
+Jun  31  42  75 492
+Jul  24  34  67 436
+Aug  15  34  47 316
+Sep  13  55  37 277
+Oct  29  54  68 525
+Nov  20  87  82 577
+Dec  17  35  61 401
+
+Jan  21  36  64 620
+Feb  26  58  80 652
+Mar  24  75  70 495
+Apr  21  70  74 514
+@end example
+
+@ifinfo
+If you are reading this in GNU Emacs using Info, you can copy the regions
+of text showing these sample files into your own test files.  This way you
+can try out the examples shown in the remainder of this document.  You do
+this by using the command @kbd{M-x write-region} to copy text from the Info
+file into a file for use with @code{awk}
+(@xref{Misc File Ops, , , emacs, GNU Emacs Manual},
+for more information).  Using this information, create your own
+@file{BBS-list} and @file{inventory-shipped} files, and practice what you
+learn in this manual.
+@end ifinfo
+
+@node Getting Started, Reading Files, This Manual, Top
+@chapter Getting Started with @code{awk}
+@cindex script, definition of
+@cindex rule, definition of
+@cindex program, definition of
+@cindex basic function of @code{gawk}
+
+The basic function of @code{awk} is to search files for lines (or other
+units of text) that contain certain patterns.  When a line matches one
+of the patterns, @code{awk} performs specified actions on that line.
+@code{awk} keeps processing input lines in this way until the end of the
+input file is reached.@refill
+
+When you run @code{awk}, you specify an @code{awk} @dfn{program} which
+tells @code{awk} what to do.  The program consists of a series of
+@dfn{rules}.  (It may also contain @dfn{function definitions}, but that
+is an advanced feature, so we will ignore it for now.
+@xref{User-defined, ,User-defined Functions}.)  Each rule specifies one
+pattern to search for, and one action to perform when that pattern is found.
+
+Syntactically, a rule consists of a pattern followed by an action.  The
+action is enclosed in curly braces to separate it from the pattern.
+Rules are usually separated by newlines.  Therefore, an @code{awk}
+program looks like this:
+
+@example
+@var{pattern} @{ @var{action} @}
+@var{pattern} @{ @var{action} @}
+@dots{}
+@end example
+
+@menu
+* Very Simple::                 A very simple example.
+* Two Rules::                   A less simple one-line example with two rules.
+* More Complex::                A more complex example.
+* Running gawk::                How to run @code{gawk} programs; 
+                                includes command line syntax.
+* Comments::                    Adding documentation to @code{gawk} programs.
+* Statements/Lines::            Subdividing or combining statements into lines.
+* When::                        When to use @code{gawk} and 
+                                when to use other things.
+@end menu
+
+@node Very Simple, Two Rules, Getting Started, Getting Started
+@section A Very Simple Example
+
+@cindex @samp{print $0}
+The following command runs a simple @code{awk} program that searches the
+input file @file{BBS-list} for the string of characters: @samp{foo}.  (A
+string of characters is usually called, a @dfn{string}.
+The term @dfn{string} is perhaps based on similar usage in English, such
+as ``a string of pearls,'' or, ``a string of cars in a train.'')
+
+@example
+awk '/foo/ @{ print $0 @}' BBS-list
+@end example
+
+@noindent
+When lines containing @samp{foo} are found, they are printed, because
+@w{@samp{print $0}} means print the current line.  (Just @samp{print} by
+itself means the same thing, so we could have written that
+instead.)
+
+You will notice that slashes, @samp{/}, surround the string @samp{foo}
+in the actual @code{awk} program.  The slashes indicate that @samp{foo}
+is a pattern to search for.  This type of pattern is called a
+@dfn{regular expression}, and is covered in more detail later
+(@pxref{Regexp, ,Regular Expressions as Patterns}).  There are
+single-quotes around the @code{awk} program so that the shell won't
+interpret any of it as special shell characters.@refill
+
+Here is what this program prints:
+
+@example
+@group
+fooey        555-1234     2400/1200/300     B
+foot         555-6699     1200/300          B
+macfoo       555-6480     1200/300          A
+sabafoo      555-2127     1200/300          C
+@end group
+@end example
+
+@cindex action, default
+@cindex pattern, default
+@cindex default action
+@cindex default pattern
+In an @code{awk} rule, either the pattern or the action can be omitted,
+but not both.  If the pattern is omitted, then the action is performed
+for @emph{every} input line.  If the action is omitted, the default
+action is to print all lines that match the pattern.
+
+Thus, we could leave out the action (the @code{print} statement and the curly
+braces) in the above example, and the result would be the same: all
+lines matching the pattern @samp{foo} would be printed.  By comparison,
+omitting the @code{print} statement but retaining the curly braces makes an
+empty action that does nothing; then no lines would be printed.
+
+@node Two Rules, More Complex, Very Simple, Getting Started
+@section An Example with Two Rules
+@cindex how @code{awk} works
+
+The @code{awk} utility reads the input files one line at a
+time.  For each line, @code{awk} tries the patterns of each of the rules.
+If several patterns match then several actions are run, in the order in
+which they appear in the @code{awk} program.  If no patterns match, then
+no actions are run.
+
+After processing all the rules (perhaps none) that match the line,
+@code{awk} reads the next line (however,
+@pxref{Next Statement, ,The @code{next} Statement}).  This continues
+until the end of the file is reached.@refill
+
+For example, the @code{awk} program:
+
+@example
+/12/  @{ print $0 @}
+/21/  @{ print $0 @}
+@end example
+
+@noindent
+contains two rules.  The first rule has the string @samp{12} as the
+pattern and @samp{print $0} as the action.  The second rule has the
+string @samp{21} as the pattern and also has @samp{print $0} as the
+action.  Each rule's action is enclosed in its own pair of braces.
+
+This @code{awk} program prints every line that contains the string
+@samp{12} @emph{or} the string @samp{21}.  If a line contains both
+strings, it is printed twice, once by each rule.
+
+If we run this program on our two sample data files, @file{BBS-list} and
+@file{inventory-shipped}, as shown here:
+
+@example
+awk '/12/ @{ print $0 @}
+     /21/ @{ print $0 @}' BBS-list inventory-shipped
+@end example
+
+@noindent
+we get the following output:
+
+@example
+aardvark     555-5553     1200/300          B
+alpo-net     555-3412     2400/1200/300     A
+barfly       555-7685     1200/300          A
+bites        555-1675     2400/1200/300     A
+core         555-2912     1200/300          C
+fooey        555-1234     2400/1200/300     B
+foot         555-6699     1200/300          B
+macfoo       555-6480     1200/300          A
+sdace        555-3430     2400/1200/300     A
+sabafoo      555-2127     1200/300          C
+sabafoo      555-2127     1200/300          C
+Jan  21  36  64 620
+Apr  21  70  74 514
+@end example
+
+@noindent
+Note how the line in @file{BBS-list} beginning with @samp{sabafoo}
+was printed twice, once for each rule.
+
+@node More Complex, Running gawk, Two Rules, Getting Started
+@comment  node-name,  next,  previous,  up
+@section A More Complex Example
+
+Here is an example to give you an idea of what typical @code{awk}
+programs do.  This example shows how @code{awk} can be used to
+summarize, select, and rearrange the output of another utility.  It uses
+features that haven't been covered yet, so don't worry if you don't
+understand all the details.
+
+@example
+ls -l | awk '$5 == "Nov" @{ sum += $4 @}
+             END @{ print sum @}'
+@end example
+
+This command prints the total number of bytes in all the files in the
+current directory that were last modified in November (of any year).
+(In the C shell you would need to type a semicolon and then a backslash
+at the end of the first line; in a @sc{posix}-compliant shell, such as the
+Bourne shell or the Bourne-Again shell, you can type the example as shown.)
+
+The @w{@samp{ls -l}} part of this example is a command that gives you a 
+listing of the files in a directory, including file size and date.
+Its output looks like this:@refill
+
+@example
+-rw-r--r--  1 close        1933 Nov  7 13:05 Makefile
+-rw-r--r--  1 close       10809 Nov  7 13:03 gawk.h
+-rw-r--r--  1 close         983 Apr 13 12:14 gawk.tab.h
+-rw-r--r--  1 close       31869 Jun 15 12:20 gawk.y
+-rw-r--r--  1 close       22414 Nov  7 13:03 gawk1.c
+-rw-r--r--  1 close       37455 Nov  7 13:03 gawk2.c
+-rw-r--r--  1 close       27511 Dec  9 13:07 gawk3.c
+-rw-r--r--  1 close        7989 Nov  7 13:03 gawk4.c
+@end example
+
+@noindent
+The first field contains read-write permissions, the second field contains
+the number of links to the file, and the third field identifies the owner of
+the file.  The fourth field contains the size of the file in bytes.  The
+fifth, sixth, and seventh fields contain the month, day, and time,
+respectively, that the file was last modified.  Finally, the eighth field
+contains the name of the file.
+
+The @code{$5 == "Nov"} in our @code{awk} program is an expression that
+tests whether the fifth field of the output from @w{@samp{ls -l}}
+matches the string @samp{Nov}.  Each time a line has the string
+@samp{Nov} in its fifth field, the action @samp{@{ sum += $4 @}} is
+performed.  This adds the fourth field (the file size) to the variable
+@code{sum}.  As a result, when @code{awk} has finished reading all the
+input lines, @code{sum} is the sum of the sizes of files whose
+lines matched the pattern.  (This works because @code{awk} variables
+are automatically initialized to zero.)@refill
+
+After the last line of output from @code{ls} has been processed, the
+@code{END} rule is executed, and the value of @code{sum} is
+printed.  In this example, the value of @code{sum} would be 80600.@refill
+
+These more advanced @code{awk} techniques are covered in later sections
+(@pxref{Actions, ,Overview of Actions}).  Before you can move on to more
+advanced @code{awk} programming, you have to know how @code{awk} interprets
+your input and displays your output.  By manipulating fields and using
+@code{print} statements, you can produce some very useful and spectacular
+looking reports.@refill
+
+@node Running gawk, Comments, More Complex, Getting Started
+@section How to Run @code{awk} Programs
+
+@ignore
+Date: Mon, 26 Aug 91 09:48:10 +0200
+From: gatech!vsoc07.cern.ch!matheys (Jean-Pol Matheys (CERN - ECP Division))
+To: uunet.UU.NET!skeeve!arnold
+Subject: RE: status check
+
+The introduction of Chapter 2 (i.e. before 2.1) should include
+the whole of section 2.4  -  it's better to tell people how to run awk programs
+before giving any examples
+
+ADR --- he's right.  but for now, don't do this because the rest of the
+chapter would need some rewriting.
+@end ignore
+
+@cindex command line formats
+@cindex running @code{awk} programs
+There are several ways to run an @code{awk} program.  If the program is
+short, it is easiest to include it in the command that runs @code{awk},
+like this:
+
+@example
+awk '@var{program}' @var{input-file1} @var{input-file2} @dots{}
+@end example
+
+@noindent
+where @var{program} consists of a series of patterns and actions, as
+described earlier.
+
+When the program is long, it is usually more convenient to put it in a file
+and run it with a command like this:
+
+@example
+awk -f @var{program-file} @var{input-file1} @var{input-file2} @dots{}
+@end example
+
+@menu
+* One-shot::                    Running a short throw-away @code{awk} program.
+* Read Terminal::               Using no input files (input from 
+                                terminal instead).
+* Long::                        Putting permanent @code{awk} programs in files.
+* Executable Scripts::          Making self-contained @code{awk} programs.
+@end menu
+
+@node One-shot, Read Terminal, Running gawk, Running gawk
+@subsection One-shot Throw-away @code{awk} Programs
+
+Once you are familiar with @code{awk}, you will often type simple
+programs at the moment you want to use them.  Then you can write the
+program as the first argument of the @code{awk} command, like this:
+
+@example
+awk '@var{program}' @var{input-file1} @var{input-file2} @dots{}
+@end example
+
+@noindent
+where @var{program} consists of a series of @var{patterns} and
+@var{actions}, as described earlier.
+
+@cindex single quotes, why needed
+This command format instructs the shell to start @code{awk} and use the
+@var{program} to process records in the input file(s).  There are single
+quotes around @var{program} so that the shell doesn't interpret any
+@code{awk} characters as special shell characters.  They also cause the
+shell to treat all of @var{program} as a single argument for
+@code{awk} and allow @var{program} to be more than one line long.@refill
+
+This format is also useful for running short or medium-sized @code{awk}
+programs from shell scripts, because it avoids the need for a separate
+file for the @code{awk} program.  A self-contained shell script is more
+reliable since there are no other files to misplace.
+
+@node Read Terminal, Long, One-shot, Running gawk
+@subsection Running @code{awk} without Input Files
+
+@cindex standard input
+@cindex input, standard
+You can also run @code{awk} without any input files.  If you type the
+command line:@refill
+
+@example
+awk '@var{program}'
+@end example
+
+@noindent
+then @code{awk} applies the @var{program} to the @dfn{standard input},
+which usually means whatever you type on the terminal.  This continues
+until you indicate end-of-file by typing @kbd{Control-d}.
+
+For example, if you execute this command:
+
+@example
+awk '/th/'
+@end example
+
+@noindent
+whatever you type next is taken as data for that @code{awk}
+program.  If you go on to type the following data:
+
+@example
+Kathy
+Ben
+Tom
+Beth
+Seth
+Karen
+Thomas
+@kbd{Control-d}
+@end example
+
+@noindent
+then @code{awk} prints this output:
+
+@example
+Kathy
+Beth
+Seth
+@end example
+
+@noindent
+@cindex case sensitivity
+@cindex pattern, case sensitive
+as matching the pattern @samp{th}.  Notice that it did not recognize
+@samp{Thomas} as matching the pattern.  The @code{awk} language is
+@dfn{case sensitive}, and matches patterns exactly.  (However, you can
+override this with the variable @code{IGNORECASE}.
+@xref{Case-sensitivity, ,Case-sensitivity in Matching}.)
+
+@node Long, Executable Scripts, Read Terminal, Running gawk
+@subsection Running Long Programs
+
+@cindex running long programs
+@cindex @samp{-f} option
+@cindex program file
+@cindex file, @code{awk} program
+Sometimes your @code{awk} programs can be very long.  In this case it is
+more convenient to put the program into a separate file.  To tell
+@code{awk} to use that file for its program, you type:@refill
+
+@example
+awk -f @var{source-file} @var{input-file1} @var{input-file2} @dots{}
+@end example
+
+The @samp{-f} instructs the @code{awk} utility to get the @code{awk} program
+from the file @var{source-file}.  Any file name can be used for
+@var{source-file}.  For example, you could put the program:@refill
+
+@example
+/th/
+@end example
+
+@noindent
+into the file @file{th-prog}.  Then this command:
+
+@example
+awk -f th-prog
+@end example
+
+@noindent
+does the same thing as this one:
+
+@example
+awk '/th/'
+@end example
+
+@noindent
+which was explained earlier (@pxref{Read Terminal, ,Running @code{awk} without Input Files}).
+Note that you don't usually need single quotes around the file name that you
+specify with @samp{-f}, because most file names don't contain any of the shell's
+special characters.  Notice that in @file{th-prog}, the @code{awk}
+program did not have single quotes around it.  The quotes are only needed
+for programs that are provided on the @code{awk} command line.
+
+If you want to identify your @code{awk} program files clearly as such,
+you can add the extension @file{.awk} to the file name.  This doesn't
+affect the execution of the @code{awk} program, but it does make
+``housekeeping'' easier.
+
+@node Executable Scripts,  , Long, Running gawk
+@c node-name, next, previous, up
+@subsection Executable @code{awk} Programs
+@cindex executable scripts
+@cindex scripts, executable
+@cindex self contained programs
+@cindex program, self contained
+@cindex @samp{#!}
+
+Once you have learned @code{awk}, you may want to write self-contained
+@code{awk} scripts, using the @samp{#!} script mechanism.  You can do
+this on many Unix systems @footnote{The @samp{#!} mechanism works on
+Unix systems derived from Berkeley Unix, System V Release 4, and some System
+V Release 3 systems.} (and someday on GNU).@refill
+
+For example, you could create a text file named @file{hello}, containing
+the following (where @samp{BEGIN} is a feature we have not yet
+discussed):
+
+@example
+#! /bin/awk -f
+
+# a sample awk program
+BEGIN    @{ print "hello, world" @}
+@end example
+
+@noindent
+After making this file executable (with the @code{chmod} command), you
+can simply type:
+
+@example
+hello
+@end example
+
+@noindent
+at the shell, and the system will arrange to run @code{awk} @footnote{The
+line beginning with @samp{#!} lists the full pathname of an interpreter
+to be run, and an optional initial command line argument to pass to that
+interpreter.  The operating system then runs the interpreter with the given
+argument and the full argument list of the executed program.  The first argument
+in the list is the full pathname of the @code{awk} program.  The rest of the
+argument list will either be options to @code{awk}, or data files,
+or both.} as if you had typed:@refill
+
+@example
+awk -f hello
+@end example
+
+@noindent
+Self-contained @code{awk} scripts are useful when you want to write a
+program which users can invoke without knowing that the program is
+written in @code{awk}.
+
+@cindex shell scripts
+@cindex scripts, shell
+If your system does not support the @samp{#!} mechanism, you can get a
+similar effect using a regular shell script.  It would look something
+like this:
+
+@example
+: The colon makes sure this script is executed by the Bourne shell.
+awk '@var{program}' "$@@"
+@end example
+
+Using this technique, it is @emph{vital} to enclose the @var{program} in
+single quotes to protect it from interpretation by the shell.  If you
+omit the quotes, only a shell wizard can predict the results.
+
+The @samp{"$@@"} causes the shell to forward all the command line
+arguments to the @code{awk} program, without interpretation.  The first
+line, which starts with a colon, is used so that this shell script will
+work even if invoked by a user who uses the C shell.
+@c Someday: (See @cite{The Bourne Again Shell}, by ??.)
+
+@node Comments, Statements/Lines, Running gawk, Getting Started
+@section Comments in @code{awk} Programs
+@cindex @samp{#}
+@cindex comments
+@cindex use of comments
+@cindex documenting @code{awk} programs
+@cindex programs, documenting
+
+A @dfn{comment} is some text that is included in a program for the sake
+of human readers, and that is not really part of the program.  Comments
+can explain what the program does, and how it works.  Nearly all
+programming languages have provisions for comments, because programs are
+typically hard to understand without their extra help.
+
+In the @code{awk} language, a comment starts with the sharp sign
+character, @samp{#}, and continues to the end of the line.  The
+@code{awk} language ignores the rest of a line following a sharp sign.
+For example, we could have put the following into @file{th-prog}:@refill
+
+@smallexample
+# This program finds records containing the pattern @samp{th}.  This is how
+# you continue comments on additional lines.
+/th/
+@end smallexample
+
+You can put comment lines into keyboard-composed throw-away @code{awk}
+programs also, but this usually isn't very useful; the purpose of a
+comment is to help you or another person understand the program at
+a later time.@refill
+
+@node Statements/Lines, When, Comments, Getting Started
+@section @code{awk} Statements versus Lines
+
+Most often, each line in an @code{awk} program is a separate statement or
+separate rule, like this:
+
+@example
+awk '/12/  @{ print $0 @}
+     /21/  @{ print $0 @}' BBS-list inventory-shipped
+@end example
+
+But sometimes statements can be more than one line, and lines can
+contain several statements.  You can split a statement into multiple
+lines by inserting a newline after any of the following:@refill
+
+@example
+,    @{    ?    :    ||    &&    do    else
+@end example
+
+@noindent
+A newline at any other point is considered the end of the statement.
+(Splitting lines after @samp{?} and @samp{:} is a minor @code{gawk}
+extension.  The @samp{?} and @samp{:} referred to here is the 
+three operand conditional expression described in
+@ref{Conditional Exp, ,Conditional Expressions}.)@refill
+
+@cindex backslash continuation
+@cindex continuation of lines
+If you would like to split a single statement into two lines at a point
+where a newline would terminate it, you can @dfn{continue} it by ending the
+first line with a backslash character, @samp{\}.  This is allowed
+absolutely anywhere in the statement, even in the middle of a string or
+regular expression.  For example:
+
+@example
+awk '/This program is too long, so continue it\
+ on the next line/ @{ print $1 @}'
+@end example
+
+@noindent
+We have generally not used backslash continuation in the sample programs in
+this manual.  Since in @code{gawk} there is no limit on the length of a line,
+it is never strictly necessary; it just makes programs prettier.  We have
+preferred to make them even more pretty by keeping the statements short.
+Backslash continuation is most useful when your @code{awk} program is in a
+separate source file, instead of typed in on the command line.  You should
+also note that many @code{awk} implementations are more picky about where
+you may use backslash continuation.  For maximal portability of your @code{awk}
+programs, it is best not to split your lines in the middle of a regular
+expression or a string.@refill
+
+@strong{Warning: backslash continuation does not work as described above
+with the C shell.}  Continuation with backslash works for @code{awk}
+programs in files, and also for one-shot programs @emph{provided} you
+are using a @sc{posix}-compliant shell, such as the Bourne shell or the
+Bourne-again shell.  But the C shell used on Berkeley Unix behaves
+differently!  There, you must use two backslashes in a row, followed by
+a newline.@refill
+
+@cindex multiple statements on one line
+When @code{awk} statements within one rule are short, you might want to put
+more than one of them on a line.  You do this by separating the statements
+with a semicolon, @samp{;}.
+This also applies to the rules themselves.
+Thus, the previous program could have been written:@refill
+
+@example
+/12/ @{ print $0 @} ; /21/ @{ print $0 @}
+@end example
+
+@noindent
+@strong{Note:} the requirement that rules on the same line must be
+separated with a semicolon is a recent change in the @code{awk}
+language; it was done for consistency with the treatment of statements
+within an action.
+
+@node When,  , Statements/Lines, Getting Started
+@section When to Use @code{awk}
+
+@cindex when to use @code{awk}
+@cindex applications of @code{awk}
+You might wonder how @code{awk} might be useful for you.  Using additional
+utility programs, more advanced patterns, field separators, arithmetic
+statements, and other selection criteria, you can produce much more
+complex output.  The @code{awk} language is very useful for producing
+reports from large amounts of raw data, such as summarizing information
+from the output of other utility programs like @code{ls}.  
+(@xref{More Complex, ,A More Complex Example}.)
+
+Programs written with @code{awk} are usually much smaller than they would
+be in other languages.  This makes @code{awk} programs easy to compose and
+use.  Often @code{awk} programs can be quickly composed at your terminal,
+used once, and thrown away.  Since @code{awk} programs are interpreted, you
+can avoid the usually lengthy edit-compile-test-debug cycle of software
+development.
+
+Complex programs have been written in @code{awk}, including a complete
+retargetable assembler for 8-bit microprocessors (@pxref{Glossary}, for
+more information) and a microcode assembler for a special purpose Prolog
+computer.  However, @code{awk}'s capabilities are strained by tasks of
+such complexity.
+
+If you find yourself writing @code{awk} scripts of more than, say, a few
+hundred lines, you might consider using a different programming
+language.  Emacs Lisp is a good choice if you need sophisticated string
+or pattern matching capabilities.  The shell is also good at string and
+pattern matching; in addition, it allows powerful use of the system
+utilities.  More conventional languages, such as C, C++, and Lisp, offer
+better facilities for system programming and for managing the complexity
+of large programs.  Programs in these languages may require more lines
+of source code than the equivalent @code{awk} programs, but they are
+easier to maintain and usually run more efficiently.@refill
+
+@node Reading Files, Printing, Getting Started, Top
+@chapter Reading Input Files
+
+@cindex reading files
+@cindex input
+@cindex standard input
+@vindex FILENAME
+In the typical @code{awk} program, all input is read either from the
+standard input (by default the keyboard, but often a pipe from another
+command) or from files whose names you specify on the @code{awk} command
+line.  If you specify input files, @code{awk} reads them in order, reading
+all the data from one before going on to the next.  The name of the current
+input file can be found in the built-in variable @code{FILENAME}
+(@pxref{Built-in Variables}).@refill
+
+The input is read in units called records, and processed by the
+rules one record at a time.  By default, each record is one line.  Each
+record is split automatically into fields, to make it more
+convenient for a rule to work on its parts.
+
+On rare occasions you will need to use the @code{getline} command,
+which can do explicit input from any number of files
+(@pxref{Getline, ,Explicit Input with @code{getline}}).@refill
+
+@menu
+* Records::                     Controlling how data is split into records.
+* Fields::                      An introduction to fields.
+* Non-Constant Fields::         Non-constant Field Numbers.
+* Changing Fields::             Changing the Contents of a Field.
+* Field Separators::            The field separator and how to change it.
+* Constant Size::               Reading constant width data.
+* Multiple Line::               Reading multi-line records.
+* Getline::                     Reading files under explicit program control
+                                using the @code{getline} function.
+* Close Input::                 Closing an input file (so you can read from
+                                the beginning once more).
+@end menu
+
+@node Records, Fields, Reading Files, Reading Files
+@section How Input is Split into Records
+
+@cindex record separator
+The @code{awk} language divides its input into records and fields.
+Records are separated by a character called the @dfn{record separator}.
+By default, the record separator is the newline character, defining
+a record to be a single line of text.@refill
+
+@iftex
+@cindex changing the record separator
+@end iftex
+@vindex RS
+Sometimes you may want to use a different character to separate your
+records.  You can use a different character by changing the built-in
+variable @code{RS}.  The value of @code{RS} is a string that says how
+to separate records; the default value is @code{"\n"}, the string containing
+just a newline character.  This is why records are, by default, single lines.
+
+@code{RS} can have any string as its value, but only the first character
+of the string is used as the record separator.  The other characters are
+ignored.  @code{RS} is exceptional in this regard; @code{awk} uses the
+full value of all its other built-in variables.@refill
+
+@ignore
+Someday this should be true!
+
+The value of @code{RS} is not limited to a one-character string.  It can
+be any regular expression (@pxref{Regexp, ,Regular Expressions as Patterns}).
+In general, each record
+ends at the next string that matches the regular expression; the next
+record starts at the end of the matching string.  This general rule is
+actually at work in the usual case, where @code{RS} contains just a
+newline: a record ends at the beginning of the next matching string (the
+next newline in the input) and the following record starts just after
+the end of this string (at the first character of the following line).
+The newline, since it matches @code{RS}, is not part of either record.@refill
+@end ignore
+
+You can change the value of @code{RS} in the @code{awk} program with the
+assignment operator, @samp{=} (@pxref{Assignment Ops, ,Assignment Expressions}).
+The new record-separator character should be enclosed in quotation marks to make
+a string constant.  Often the right time to do this is at the beginning
+of execution, before any input has been processed, so that the very
+first record will be read with the proper separator.  To do this, use
+the special @code{BEGIN} pattern
+(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}).  For
+example:@refill
+
+@example
+awk 'BEGIN @{ RS = "/" @} ; @{ print $0 @}' BBS-list
+@end example
+
+@noindent
+changes the value of @code{RS} to @code{"/"}, before reading any input.
+This is a string whose first character is a slash; as a result, records
+are separated by slashes.  Then the input file is read, and the second
+rule in the @code{awk} program (the action with no pattern) prints each
+record.  Since each @code{print} statement adds a newline at the end of
+its output, the effect of this @code{awk} program is to copy the input
+with each slash changed to a newline.
+
+Another way to change the record separator is on the command line,
+using the variable-assignment feature
+(@pxref{Command Line, ,Invoking @code{awk}}).@refill
+
+@example
+awk '@{ print $0 @}' RS="/" BBS-list
+@end example
+
+@noindent
+This sets @code{RS} to @samp{/} before processing @file{BBS-list}.
+
+Reaching the end of an input file terminates the current input record,
+even if the last character in the file is not the character in @code{RS}.
+
+@ignore
+@c merge the preceding paragraph and this stuff into one paragraph
+@c and put it in an `expert info' section.
+This produces correct behavior in the vast majority of cases, although
+the following (extreme) pipeline prints a surprising @samp{1}.  (There
+is one field, consisting of a newline.)
+
+@example
+echo | awk 'BEGIN @{ RS = "a" @} ; @{ print NF @}'
+@end example
+
+@end ignore
+
+The empty string, @code{""} (a string of no characters), has a special meaning
+as the value of @code{RS}: it means that records are separated only
+by blank lines.  @xref{Multiple Line, ,Multiple-Line Records}, for more details.
+
+@cindex number of records, @code{NR} or @code{FNR}
+@vindex NR
+@vindex FNR
+The @code{awk} utility keeps track of the number of records that have
+been read so far from the current input file.  This value is stored in a
+built-in variable called @code{FNR}.  It is reset to zero when a new
+file is started.  Another built-in variable, @code{NR}, is the total
+number of input records read so far from all files.  It starts at zero
+but is never automatically reset to zero.
+
+If you change the value of @code{RS} in the middle of an @code{awk} run,
+the new value is used to delimit subsequent records, but the record
+currently being processed (and records already processed) are not
+affected.
+
+@node Fields, Non-Constant Fields, Records, Reading Files
+@section Examining Fields
+
+@cindex examining fields
+@cindex fields
+@cindex accessing fields
+When @code{awk} reads an input record, the record is
+automatically separated or @dfn{parsed} by the interpreter into chunks
+called @dfn{fields}.  By default, fields are separated by whitespace,
+like words in a line.
+Whitespace in @code{awk} means any string of one or more spaces and/or
+tabs; other characters such as newline, formfeed, and so on, that are
+considered whitespace by other languages are @emph{not} considered
+whitespace by @code{awk}.@refill
+
+The purpose of fields is to make it more convenient for you to refer to
+these pieces of the record.  You don't have to use them---you can
+operate on the whole record if you wish---but fields are what make
+simple @code{awk} programs so powerful.
+
+@cindex @code{$} (field operator)
+@cindex operators, @code{$}
+To refer to a field in an @code{awk} program, you use a dollar-sign,
+@samp{$}, followed by the number of the field you want.  Thus, @code{$1}
+refers to the first field, @code{$2} to the second, and so on.  For
+example, suppose the following is a line of input:@refill
+
+@example
+This seems like a pretty nice example.
+@end example
+
+@noindent
+Here the first field, or @code{$1}, is @samp{This}; the second field, or
+@code{$2}, is @samp{seems}; and so on.  Note that the last field,
+@code{$7}, is @samp{example.}.  Because there is no space between the
+@samp{e} and the @samp{.}, the period is considered part of the seventh
+field.@refill
+
+No matter how many fields there are, the last field in a record can be
+represented by @code{$NF}.  So, in the example above, @code{$NF} would
+be the same as @code{$7}, which is @samp{example.}.  Why this works is
+explained below (@pxref{Non-Constant Fields, ,Non-constant Field Numbers}).
+If you try to refer to a field beyond the last one, such as @code{$8}
+when the record has only 7 fields, you get the empty string.@refill
+
+@vindex NF
+@cindex number of fields, @code{NF}
+Plain @code{NF}, with no @samp{$}, is a built-in variable whose value
+is the number of fields in the current record.
+
+@code{$0}, which looks like an attempt to refer to the zeroth field, is
+a special case: it represents the whole input record.  This is what you
+would use if you weren't interested in fields.
+
+Here are some more examples:
+
+@example
+awk '$1 ~ /foo/ @{ print $0 @}' BBS-list
+@end example
+
+@noindent
+This example prints each record in the file @file{BBS-list} whose first
+field contains the string @samp{foo}.  The operator @samp{~} is called a
+@dfn{matching operator} (@pxref{Comparison Ops, ,Comparison Expressions});
+it tests whether a string (here, the field @code{$1}) matches a given regular
+expression.@refill
+
+By contrast, the following example:
+
+@example
+awk '/foo/ @{ print $1, $NF @}' BBS-list
+@end example
+
+@noindent
+looks for @samp{foo} in @emph{the entire record} and prints the first
+field and the last field for each input record containing a
+match.@refill
+
+@node Non-Constant Fields, Changing Fields, Fields, Reading Files
+@section Non-constant Field Numbers
+
+The number of a field does not need to be a constant.  Any expression in
+the @code{awk} language can be used after a @samp{$} to refer to a
+field.  The value of the expression specifies the field number.  If the
+value is a string, rather than a number, it is converted to a number.
+Consider this example:@refill
+
+@example
+awk '@{ print $NR @}'
+@end example
+
+@noindent
+Recall that @code{NR} is the number of records read so far: 1 in the
+first record, 2 in the second, etc.  So this example prints the first
+field of the first record, the second field of the second record, and so
+on.  For the twentieth record, field number 20 is printed; most likely,
+the record has fewer than 20 fields, so this prints a blank line.
+
+Here is another example of using expressions as field numbers:
+
+@example
+awk '@{ print $(2*2) @}' BBS-list
+@end example
+
+The @code{awk} language must evaluate the expression @code{(2*2)} and use
+its value as the number of the field to print.  The @samp{*} sign
+represents multiplication, so the expression @code{2*2} evaluates to 4.
+The parentheses are used so that the multiplication is done before the
+@samp{$} operation; they are necessary whenever there is a binary
+operator in the field-number expression.  This example, then, prints the
+hours of operation (the fourth field) for every line of the file
+@file{BBS-list}.@refill
+
+If the field number you compute is zero, you get the entire record.
+Thus, @code{$(2-2)} has the same value as @code{$0}.  Negative field
+numbers are not allowed.
+
+The number of fields in the current record is stored in the built-in
+variable @code{NF} (@pxref{Built-in Variables}).  The expression
+@code{$NF} is not a special feature: it is the direct consequence of
+evaluating @code{NF} and using its value as a field number.
+
+@node Changing Fields, Field Separators, Non-Constant Fields, Reading Files
+@section Changing the Contents of a Field
+
+@cindex field, changing contents of
+@cindex changing contents of a field
+@cindex assignment to fields
+You can change the contents of a field as seen by @code{awk} within an
+@code{awk} program; this changes what @code{awk} perceives as the
+current input record.  (The actual input is untouched: @code{awk} never
+modifies the input file.)
+
+Consider this example:
+
+@smallexample
+awk '@{ $3 = $2 - 10; print $2, $3 @}' inventory-shipped
+@end smallexample
+
+@noindent
+The @samp{-} sign represents subtraction, so this program reassigns
+field three, @code{$3}, to be the value of field two minus ten,
+@code{$2 - 10}.  (@xref{Arithmetic Ops, ,Arithmetic Operators}.)
+Then field two, and the new value for field three, are printed.  
+
+In order for this to work, the text in field @code{$2} must make sense
+as a number; the string of characters must be converted to a number in
+order for the computer to do arithmetic on it.  The number resulting
+from the subtraction is converted back to a string of characters which
+then becomes field three.
+@xref{Conversion, ,Conversion of Strings and Numbers}.@refill
+
+When you change the value of a field (as perceived by @code{awk}), the
+text of the input record is recalculated to contain the new field where
+the old one was.  Therefore, @code{$0} changes to reflect the altered
+field.  Thus,
+
+@smallexample
+awk '@{ $2 = $2 - 10; print $0 @}' inventory-shipped
+@end smallexample
+
+@noindent
+prints a copy of the input file, with 10 subtracted from the second
+field of each line.
+
+You can also assign contents to fields that are out of range.  For
+example:
+
+@smallexample
+awk '@{ $6 = ($5 + $4 + $3 + $2) ; print $6 @}' inventory-shipped
+@end smallexample
+
+@noindent
+We've just created @code{$6}, whose value is the sum of fields
+@code{$2}, @code{$3}, @code{$4}, and @code{$5}.  The @samp{+} sign
+represents addition.  For the file @file{inventory-shipped}, @code{$6}
+represents the total number of parcels shipped for a particular month.
+
+Creating a new field changes the internal @code{awk} copy of the current
+input record---the value of @code{$0}.  Thus, if you do @samp{print $0}
+after adding a field, the record printed includes the new field, with
+the appropriate number of field separators between it and the previously
+existing fields.
+
+This recomputation affects and is affected by several features not yet
+discussed, in particular, the @dfn{output field separator}, @code{OFS},
+which is used to separate the fields (@pxref{Output Separators}), and
+@code{NF} (the number of fields; @pxref{Fields, ,Examining Fields}).
+For example, the value of @code{NF} is set to the number of the highest
+field you create.@refill
+
+Note, however, that merely @emph{referencing} an out-of-range field
+does @emph{not} change the value of either @code{$0} or @code{NF}.
+Referencing an out-of-range field merely produces a null string.  For
+example:@refill
+
+@smallexample
+if ($(NF+1) != "")
+    print "can't happen"
+else
+    print "everything is normal"
+@end smallexample
+
+@noindent
+should print @samp{everything is normal}, because @code{NF+1} is certain
+to be out of range.  (@xref{If Statement, ,The @code{if} Statement},
+for more information about @code{awk}'s @code{if-else} statements.)@refill
+
+It is important to note that assigning to a field will change the
+value of @code{$0}, but will not change the value of @code{NF},
+even when you assign the null string to a field.  For example:
+
+@smallexample
+echo a b c d | awk '@{ OFS = ":"; $2 = "" ; print ; print NF @}'
+@end smallexample
+
+@noindent
+prints
+
+@smallexample
+a::c:d
+4
+@end smallexample
+
+@noindent
+The field is still there, it just has an empty value.  You can tell
+because there are two colons in a row.
+
+@node Field Separators, Constant Size, Changing Fields, Reading Files
+@section Specifying how Fields are Separated
+@vindex FS
+@cindex fields, separating
+@cindex field separator, @code{FS}
+@cindex @samp{-F} option
+
+(This section is rather long; it describes one of the most fundamental
+operations in @code{awk}.  If you are a novice with @code{awk}, we
+recommend that you re-read this section after you have studied the
+section on regular expressions, @ref{Regexp, ,Regular Expressions as Patterns}.)
+
+The way @code{awk} splits an input record into fields is controlled by
+the @dfn{field separator}, which is a single character or a regular
+expression.  @code{awk} scans the input record for matches for the
+separator; the fields themselves are the text between the matches.  For
+example, if the field separator is @samp{oo}, then the following line:
+
+@smallexample
+moo goo gai pan
+@end smallexample
+
+@noindent
+would be split into three fields: @samp{m}, @samp{@ g} and @samp{@ gai@ 
+pan}.
+
+The field separator is represented by the built-in variable @code{FS}.
+Shell programmers take note!  @code{awk} does not use the name @code{IFS}
+which is used by the shell.@refill
+
+You can change the value of @code{FS} in the @code{awk} program with the
+assignment operator, @samp{=} (@pxref{Assignment Ops, ,Assignment Expressions}).
+Often the right time to do this is at the beginning of execution,
+before any input has been processed, so that the very first record
+will be read with the proper separator.  To do this, use the special
+@code{BEGIN} pattern
+(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}).
+For example, here we set the value of @code{FS} to the string
+@code{","}:@refill
+
+@smallexample
+awk 'BEGIN @{ FS = "," @} ; @{ print $2 @}'
+@end smallexample
+
+@noindent
+Given the input line,
+
+@smallexample
+John Q. Smith, 29 Oak St., Walamazoo, MI 42139
+@end smallexample
+
+@noindent
+this @code{awk} program extracts the string @samp{@ 29 Oak St.}.
+
+@cindex field separator, choice of
+@cindex regular expressions as field separators
+Sometimes your input data will contain separator characters that don't
+separate fields the way you thought they would.  For instance, the
+person's name in the example we've been using might have a title or
+suffix attached, such as @samp{John Q. Smith, LXIX}.  From input
+containing such a name:
+
+@smallexample
+John Q. Smith, LXIX, 29 Oak St., Walamazoo, MI 42139
+@end smallexample
+
+@noindent
+the previous sample program would extract @samp{@ LXIX}, instead of
+@samp{@ 29 Oak St.}.  If you were expecting the program to print the
+address, you would be surprised.  So choose your data layout and
+separator characters carefully to prevent such problems.
+
+As you know, by default, fields are separated by whitespace sequences
+(spaces and tabs), not by single spaces: two spaces in a row do not
+delimit an empty field.  The default value of the field separator is a
+string @w{@code{" "}} containing a single space.  If this value were
+interpreted in the usual way, each space character would separate
+fields, so two spaces in a row would make an empty field between them.
+The reason this does not happen is that a single space as the value of
+@code{FS} is a special case: it is taken to specify the default manner
+of delimiting fields.
+
+If @code{FS} is any other single character, such as @code{","}, then
+each occurrence of that character separates two fields.  Two consecutive
+occurrences delimit an empty field.  If the character occurs at the
+beginning or the end of the line, that too delimits an empty field.  The
+space character is the only single character which does not follow these
+rules.
+
+More generally, the value of @code{FS} may be a string containing any
+regular expression.  Then each match in the record for the regular
+expression separates fields.  For example, the assignment:@refill
+
+@smallexample
+FS = ", \t"
+@end smallexample
+
+@noindent
+makes every area of an input line that consists of a comma followed by a
+space and a tab, into a field separator.  (@samp{\t} stands for a
+tab.)@refill
+
+For a less trivial example of a regular expression, suppose you want
+single spaces to separate fields the way single commas were used above.
+You can set @code{FS} to @w{@code{"[@ ]"}}.  This regular expression
+matches a single space and nothing else.
+
+@c the following index entry is an overfull hbox.  --mew 30jan1992
+@cindex field separator: on command line
+@cindex command line, setting @code{FS} on
+@code{FS} can be set on the command line.  You use the @samp{-F} argument to
+do so.  For example:
+
+@smallexample
+awk -F, '@var{program}' @var{input-files}
+@end smallexample
+
+@noindent
+sets @code{FS} to be the @samp{,} character.  Notice that the argument uses
+a capital @samp{F}.  Contrast this with @samp{-f}, which specifies a file
+containing an @code{awk} program.  Case is significant in command options:
+the @samp{-F} and @samp{-f} options have nothing to do with each other.
+You can use both options at the same time to set the @code{FS} argument
+@emph{and} get an @code{awk} program from a file.@refill
+
+@c begin expert info
+The value used for the argument to @samp{-F} is processed in exactly the
+same way as assignments to the built-in variable @code{FS}.  This means that
+if the field separator contains special characters, they must be escaped
+appropriately.  For example, to use a @samp{\} as the field separator, you
+would have to type:
+
+@smallexample
+# same as FS = "\\" 
+awk -F\\\\ '@dots{}' files @dots{}
+@end smallexample
+
+@noindent
+Since @samp{\} is used for quoting in the shell, @code{awk} will see
+@samp{-F\\}.  Then @code{awk} processes the @samp{\\} for escape
+characters (@pxref{Constants, ,Constant Expressions}), finally yielding
+a single @samp{\} to be used for the field separator.
+@c end expert info
+
+As a special case, in compatibility mode
+(@pxref{Command Line, ,Invoking @code{awk}}), if the
+argument to @samp{-F} is @samp{t}, then @code{FS} is set to the tab
+character.  (This is because if you type @samp{-F\t}, without the quotes,
+at the shell, the @samp{\} gets deleted, so @code{awk} figures that you
+really want your fields to be separated with tabs, and not @samp{t}s.
+Use @samp{-v FS="t"} on the command line if you really do want to separate
+your fields with @samp{t}s.)@refill
+
+For example, let's use an @code{awk} program file called @file{baud.awk}
+that contains the pattern @code{/300/}, and the action @samp{print $1}.
+Here is the program:
+
+@smallexample
+/300/   @{ print $1 @}
+@end smallexample
+
+Let's also set @code{FS} to be the @samp{-} character, and run the
+program on the file @file{BBS-list}.  The following command prints a
+list of the names of the bulletin boards that operate at 300 baud and
+the first three digits of their phone numbers:@refill
+
+@smallexample
+awk -F- -f baud.awk BBS-list
+@end smallexample
+
+@noindent
+It produces this output:
+
+@smallexample
+aardvark     555
+alpo
+barfly       555
+bites        555
+camelot      555
+core         555
+fooey        555
+foot         555
+macfoo       555
+sdace        555
+sabafoo      555
+@end smallexample
+
+@noindent
+Note the second line of output.  If you check the original file, you will
+see that the second line looked like this:
+
+@smallexample
+alpo-net     555-3412     2400/1200/300     A
+@end smallexample
+
+The @samp{-} as part of the system's name was used as the field
+separator, instead of the @samp{-} in the phone number that was
+originally intended.  This demonstrates why you have to be careful in
+choosing your field and record separators.
+
+The following program searches the system password file, and prints
+the entries for users who have no password:
+
+@smallexample
+awk -F: '$2 == ""' /etc/passwd
+@end smallexample
+
+@noindent
+Here we use the @samp{-F} option on the command line to set the field
+separator.  Note that fields in @file{/etc/passwd} are separated by
+colons.  The second field represents a user's encrypted password, but if
+the field is empty, that user has no password.
+
+@c begin expert info
+According to the @sc{posix} standard, @code{awk} is supposed to behave
+as if each record is split into fields at the time that it is read.
+In particular, this means that you can change the value of @code{FS}
+after a record is read, but before any of the fields are referenced.
+The value of the fields (i.e. how they were split) should reflect the
+old value of @code{FS}, not the new one.
+
+However, many implementations of @code{awk} do not do this.  Instead,
+they defer splitting the fields until a field reference actually happens,
+using the @emph{current} value of @code{FS}!  This behavior can be difficult
+to diagnose. The following example illustrates the results of the two methods.
+(The @code{sed} command prints just the first line of @file{/etc/passwd}.)
+
+@smallexample
+sed 1q /etc/passwd | awk '@{ FS = ":" ; print $1 @}'
+@end smallexample
+
+@noindent
+will usually print
+
+@smallexample
+root
+@end smallexample
+
+@noindent
+on an incorrect implementation of @code{awk}, while @code{gawk}
+will print something like
+
+@smallexample
+root:nSijPlPhZZwgE:0:0:Root:/:
+@end smallexample
+@c end expert info
+
+@c begin expert info
+There is an important difference between the two cases of @samp{FS = @w{" "}}
+(a single blank) and @samp{FS = @w{"[ \t]+"}} (which is a regular expression
+matching one or more blanks or tabs).  For both values of @code{FS}, fields
+are separated by runs of blanks and/or tabs.  However, when the value of
+@code{FS} is @code{" "}, @code{awk} will strip leading and trailing whitespace
+from the record, and then decide where the fields are.  
+
+For example, the following expression prints @samp{b}:
+
+@smallexample
+echo ' a b c d ' | awk '@{ print $2 @}'
+@end smallexample
+
+@noindent
+However, the following prints @samp{a}:
+
+@smallexample
+echo ' a b c d ' | awk 'BEGIN @{ FS = "[ \t]+" @} ; @{ print $2 @}'
+@end smallexample
+
+@noindent
+In this case, the first field is null.
+
+The stripping of leading and trailing whitespace also comes into
+play whenever @code{$0} is recomputed.  For instance, this pipeline
+
+@smallexample
+echo '   a b c d' | awk '@{ print; $2 = $2; print @}'
+@end smallexample
+
+@noindent
+produces this output:
+
+@smallexample
+   a b c d
+a b c d
+@end smallexample
+
+@noindent
+The first @code{print} statement prints the record as it was read,
+with leading whitespace intact.  The assignment to @code{$2} rebuilds
+@code{$0} by concatenating @code{$1} through @code{$NF} together,
+separated by the value of @code{OFS}.  Since the leading whitespace
+was ignored when finding @code{$1}, it is not part of the new @code{$0}.
+Finally, the last @code{print} statement prints the new @code{$0}.
+@c end expert info
+
+The following table summarizes how fields are split, based on the
+value of @code{FS}.
+
+@table @code
+@item FS == " "
+Fields are separated by runs of whitespace.  Leading and trailing
+whitespace are ignored.  This is the default.
+
+@item FS == @var{any single character}
+Fields are separated by each occurrence of the character.  Multiple
+successive occurrences delimit empty fields, as do leading and
+trailing occurrences.
+
+@item FS == @var{regexp}
+Fields are separated by occurrences of characters that match @var{regexp}.
+Leading and trailing matches of @var{regexp} delimit empty fields.
+@end table
+
+@node Constant Size, Multiple Line, Field Separators, Reading Files
+@section Reading Fixed-width Data
+
+(This section discusses an advanced, experimental feature.  If you are
+a novice @code{awk} user, you may wish to skip it on the first reading.)
+
+@code{gawk} 2.13 introduced a new facility for dealing with fixed-width fields
+with no distinctive field separator.  Data of this nature arises typically
+in one of at least two ways:  the input for old FORTRAN programs where
+numbers are run together, and the output of programs that did not anticipate
+the use of their output as input for other programs.
+
+An example of the latter is a table where all the columns are lined up by
+the use of a variable number of spaces and @emph{empty fields are just
+spaces}.  Clearly, @code{awk}'s normal field splitting based on @code{FS}
+will not work well in this case.  (Although a portable @code{awk} program
+can use a series of @code{substr} calls on @code{$0}, this is awkward and
+inefficient for a large number of fields.)@refill
+
+The splitting of an input record into fixed-width fields is specified by
+assigning a string containing space-separated numbers to the built-in
+variable @code{FIELDWIDTHS}.  Each number specifies the width of the field
+@emph{including} columns between fields.  If you want to ignore the columns
+between fields, you can specify the width as a separate field that is
+subsequently ignored.
+
+The following data is the output of the @code{w} utility.  It is useful
+to illustrate the use of @code{FIELDWIDTHS}.
+
+@smallexample
+ 10:06pm  up 21 days, 14:04,  23 users
+User     tty       login@  idle   JCPU   PCPU  what
+hzuo     ttyV0     8:58pm            9      5  vi p24.tex 
+hzang    ttyV3     6:37pm    50                -csh 
+eklye    ttyV5     9:53pm            7      1  em thes.tex 
+dportein ttyV6     8:17pm  1:47                -csh 
+gierd    ttyD3    10:00pm     1                elm 
+dave     ttyD4     9:47pm            4      4  w 
+brent    ttyp0    26Jun91  4:46  26:46   4:41  bash 
+dave     ttyq4    26Jun9115days     46     46  wnewmail 
+@end smallexample
+
+The following program takes the above input, converts the idle time to
+number of seconds and prints out the first two fields and the calculated
+idle time.  (This program uses a number of @code{awk} features that
+haven't been introduced yet.)@refill
+
+@smallexample
+BEGIN  @{ FIELDWIDTHS = "9 6 10 6 7 7 35" @}
+NR > 2 @{
+    idle = $4
+    sub(/^  */, "", idle)   # strip leading spaces
+    if (idle == "") idle = 0
+    if (idle ~ /:/) @{ split(idle, t, ":"); idle = t[1] * 60 + t[2] @}
+    if (idle ~ /days/) @{ idle *= 24 * 60 * 60 @}
+ 
+    print $1, $2, idle
+@}
+@end smallexample
+
+Here is the result of running the program on the data:
+
+@smallexample
+hzuo      ttyV0  0
+hzang     ttyV3  50
+eklye     ttyV5  0
+dportein  ttyV6  107
+gierd     ttyD3  1
+dave      ttyD4  0
+brent     ttyp0  286
+dave      ttyq4  1296000
+@end smallexample
+
+Another (possibly more practical) example of fixed-width input data
+would be the input from a deck of balloting cards.  In some parts of
+the United States, voters make their choices by punching holes in computer
+cards.  These cards are then processed to count the votes for any particular
+candidate or on any particular issue.  Since a voter may choose not to
+vote on some issue, any column on the card may be empty.  An @code{awk}
+program for processing such data could use the @code{FIELDWIDTHS} feature
+to simplify reading the data.@refill
+
+@c of course, getting gawk to run on a system with card readers is
+@c another story!
+
+This feature is still experimental, and will likely evolve over time.
+
+@node Multiple Line, Getline, Constant Size, Reading Files
+@section Multiple-Line Records
+
+@cindex multiple line records
+@cindex input, multiple line records
+@cindex reading files, multiple line records
+@cindex records, multiple line
+In some data bases, a single line cannot conveniently hold all the
+information in one entry.  In such cases, you can use multi-line
+records.
+
+The first step in doing this is to choose your data format: when records
+are not defined as single lines, how do you want to define them?
+What should separate records?
+
+One technique is to use an unusual character or string to separate
+records.  For example, you could use the formfeed character (written
+@code{\f} in @code{awk}, as in C) to separate them, making each record
+a page of the file.  To do this, just set the variable @code{RS} to
+@code{"\f"} (a string containing the formfeed character).  Any
+other character could equally well be used, as long as it won't be part
+of the data in a record.@refill
+
+@ignore
+Another technique is to have blank lines separate records.  The string
+@code{"^\n+"} is a regular expression that matches any sequence of
+newlines starting at the beginning of a line---in other words, it
+matches a sequence of blank lines.  If you set @code{RS} to this string,
+a record always ends at the first blank line encountered.  In
+addition, a regular expression always matches the longest possible
+sequence when there is a choice.  So the next record doesn't start until
+the first nonblank line that follows---no matter how many blank lines
+appear in a row, they are considered one record-separator.
+@end ignore
+
+Another technique is to have blank lines separate records.  By a special
+dispensation, a null string as the value of @code{RS} indicates that
+records are separated by one or more blank lines.  If you set @code{RS}
+to the null string, a record always ends at the first blank line
+encountered.  And the next record doesn't start until the first nonblank
+line that follows---no matter how many blank lines appear in a row, they
+are considered one record-separator. (End of file is also considered
+a record separator.)@refill
+@c !!! This use of `end of file' is confusing.  Needs to be clarified.
+
+The second step is to separate the fields in the record.  One way to do
+this is to put each field on a separate line: to do this, just set the
+variable @code{FS} to the string @code{"\n"}.  (This simple regular
+expression matches a single newline.)
+
+Another way to separate fields is to divide each of the lines into fields
+in the normal manner.  This happens by default as a result of a special
+feature: when @code{RS} is set to the null string, the newline character
+@emph{always} acts as a field separator.  This is in addition to whatever
+field separations result from @code{FS}.
+
+The original motivation for this special exception was probably so that
+you get useful behavior in the default case (i.e., @w{@code{FS == " "}}).
+This feature can be a problem if you really don't want the
+newline character to separate fields, since there is no way to
+prevent it.  However, you can work around this by using the @code{split}
+function to break up the record manually
+(@pxref{String Functions, ,Built-in Functions for String Manipulation}).@refill
+
+@ignore
+Here are two ways to use records separated by blank lines and break each
+line into fields normally:
+
+@example
+awk 'BEGIN @{ RS = ""; FS = "[ \t\n]+" @} @{ print $1 @}' BBS-list
+
+@exdent @r{or}
+
+awk 'BEGIN @{ RS = "^\n+"; FS = "[ \t\n]+" @} @{ print $1 @}' BBS-list
+@end example
+@end ignore
+
+@ignore
+Here is how to use records separated by blank lines and break each
+line into fields normally:
+
+@example
+awk 'BEGIN @{ RS = ""; FS = "[ \t\n]+" @} ; @{ print $1 @}' BBS-list
+@end example
+@end ignore
+
+@node Getline, Close Input, Multiple Line, Reading Files
+@section Explicit Input with @code{getline}
+
+@findex getline
+@cindex input, explicit
+@cindex explicit input
+@cindex input, @code{getline} command
+@cindex reading files, @code{getline} command
+So far we have been getting our input files from @code{awk}'s main
+input stream---either the standard input (usually your terminal) or the
+files specified on the command line.  The @code{awk} language has a
+special built-in command called @code{getline} that
+can be used to read input under your explicit control.@refill
+
+This command is quite complex and should @emph{not} be used by
+beginners.  It is covered here because this is the chapter on input.
+The examples that follow the explanation of the @code{getline} command
+include material that has not been covered yet.  Therefore, come back
+and study the @code{getline} command @emph{after} you have reviewed the
+rest of this manual and have a good knowledge of how @code{awk} works.
+
+@vindex ERRNO
+@cindex differences: @code{gawk} and @code{awk}
+@code{getline} returns 1 if it finds a record, and 0 if the end of the
+file is encountered.  If there is some error in getting a record, such
+as a file that cannot be opened, then @code{getline} returns @minus{}1.
+In this case, @code{gawk} sets the variable @code{ERRNO} to a string
+describing the error that occurred.
+
+In the following examples, @var{command} stands for a string value that
+represents a shell command.
+
+@table @code
+@item getline
+The @code{getline} command can be used without arguments to read input
+from the current input file.  All it does in this case is read the next
+input record and split it up into fields.  This is useful if you've
+finished processing the current record, but you want to do some special
+processing @emph{right now} on the next record.  Here's an
+example:@refill
+
+@example
+awk '@{
+     if (t = index($0, "/*")) @{
+          if (t > 1)
+               tmp = substr($0, 1, t - 1)
+          else
+               tmp = ""
+          u = index(substr($0, t + 2), "*/")
+          while (u == 0) @{
+               getline
+               t = -1
+               u = index($0, "*/")
+          @}
+          if (u <= length($0) - 2)
+               $0 = tmp substr($0, t + u + 3)
+          else
+               $0 = tmp
+     @}
+     print $0
+@}'
+@end example
+
+This @code{awk} program deletes all C-style comments, @samp{/* @dots{}
+*/}, from the input.  By replacing the @samp{print $0} with other
+statements, you could perform more complicated processing on the
+decommented input, like searching for matches of a regular
+expression.  (This program has a subtle problem---can you spot it?)
+
+@c the program to remove comments doesn't work if one
+@c comment ends and another begins on the same line.  (Your
+@c idea for restart would be useful here).  --- brennan@boeing.com
+
+This form of the @code{getline} command sets @code{NF} (the number of
+fields; @pxref{Fields, ,Examining Fields}), @code{NR} (the number of
+records read so far; @pxref{Records, ,How Input is Split into Records}),
+@code{FNR} (the number of records read from this input file), and the
+value of @code{$0}.
+
+@strong{Note:} the new value of @code{$0} is used in testing
+the patterns of any subsequent rules.  The original value
+of @code{$0} that triggered the rule which executed @code{getline}
+is lost.  By contrast, the @code{next} statement reads a new record
+but immediately begins processing it normally, starting with the first
+rule in the program.  @xref{Next Statement, ,The @code{next} Statement}.
+
+@item getline @var{var}
+This form of @code{getline} reads a record into the variable @var{var}.
+This is useful when you want your program to read the next record from
+the current input file, but you don't want to subject the record to the
+normal input processing.
+
+For example, suppose the next line is a comment, or a special string,
+and you want to read it, but you must make certain that it won't trigger
+any rules.  This version of @code{getline} allows you to read that line
+and store it in a variable so that the main
+read-a-line-and-check-each-rule loop of @code{awk} never sees it.
+
+The following example swaps every two lines of input.  For example, given:
+
+@example
+wan
+tew
+free
+phore
+@end example
+
+@noindent
+it outputs:
+
+@example
+tew
+wan
+phore
+free
+@end example
+
+@noindent
+Here's the program:
+
+@example
+@group
+awk '@{
+     if ((getline tmp) > 0) @{
+          print tmp
+          print $0
+     @} else
+          print $0
+@}'
+@end group
+@end example
+
+The @code{getline} function used in this way sets only the variables
+@code{NR} and @code{FNR} (and of course, @var{var}).  The record is not
+split into fields, so the values of the fields (including @code{$0}) and
+the value of @code{NF} do not change.@refill
+
+@item getline < @var{file}
+@cindex input redirection
+@cindex redirection of input
+This form of the @code{getline} function takes its input from the file
+@var{file}.  Here @var{file} is a string-valued expression that
+specifies the file name.  @samp{< @var{file}} is called a @dfn{redirection}
+since it directs input to come from a different place.
+
+This form is useful if you want to read your input from a particular
+file, instead of from the main input stream.  For example, the following
+program reads its input record from the file @file{foo.input} when it
+encounters a first field with a value equal to 10 in the current input
+file.@refill
+
+@example
+awk '@{
+    if ($1 == 10) @{
+         getline < "foo.input"
+         print
+    @} else
+         print
+@}'
+@end example
+
+Since the main input stream is not used, the values of @code{NR} and
+@code{FNR} are not changed.  But the record read is split into fields in
+the normal manner, so the values of @code{$0} and other fields are
+changed.  So is the value of @code{NF}.
+
+This does not cause the record to be tested against all the patterns
+in the @code{awk} program, in the way that would happen if the record
+were read normally by the main processing loop of @code{awk}.  However
+the new record is tested against any subsequent rules, just as when
+@code{getline} is used without a redirection.
+
+@item getline @var{var} < @var{file}
+This form of the @code{getline} function takes its input from the file
+@var{file} and puts it in the variable @var{var}.  As above, @var{file}
+is a string-valued expression that specifies the file from which to read.
+
+In this version of @code{getline}, none of the built-in variables are
+changed, and the record is not split into fields.  The only variable
+changed is @var{var}.
+
+For example, the following program copies all the input files to the
+output, except for records that say @w{@samp{@@include @var{filename}}}.
+Such a record is replaced by the contents of the file
+@var{filename}.@refill
+
+@example
+awk '@{
+     if (NF == 2 && $1 == "@@include") @{
+          while ((getline line < $2) > 0)
+               print line
+          close($2)
+     @} else
+          print
+@}'
+@end example
+
+Note here how the name of the extra input file is not built into
+the program; it is taken from the data, from the second field on
+the @samp{@@include} line.@refill
+
+The @code{close} function is called to ensure that if two identical
+@samp{@@include} lines appear in the input, the entire specified file is
+included twice.  @xref{Close Input, ,Closing Input Files and Pipes}.@refill
+
+One deficiency of this program is that it does not process nested
+@samp{@@include} statements the way a true macro preprocessor would.
+
+@item @var{command} | getline
+You can @dfn{pipe} the output of a command into @code{getline}.  A pipe is
+simply a way to link the output of one program to the input of another.  In
+this case, the string @var{command} is run as a shell command and its output
+is piped into @code{awk} to be used as input.  This form of @code{getline}
+reads one record from the pipe.
+
+For example, the following program copies input to output, except for lines
+that begin with @samp{@@execute}, which are replaced by the output produced by
+running the rest of the line as a shell command:
+
+@example
+awk '@{
+     if ($1 == "@@execute") @{
+          tmp = substr($0, 10)
+          while ((tmp | getline) > 0)
+               print
+          close(tmp)
+     @} else
+          print
+@}'
+@end example
+
+@noindent
+The @code{close} function is called to ensure that if two identical
+@samp{@@execute} lines appear in the input, the command is run for
+each one.  @xref{Close Input, ,Closing Input Files and Pipes}.
+
+Given the input:
+
+@example
+foo
+bar
+baz
+@@execute who
+bletch
+@end example
+
+@noindent
+the program might produce:
+
+@example
+foo
+bar
+baz
+hack     ttyv0   Jul 13 14:22
+hack     ttyp0   Jul 13 14:23     (gnu:0)
+hack     ttyp1   Jul 13 14:23     (gnu:0)
+hack     ttyp2   Jul 13 14:23     (gnu:0)
+hack     ttyp3   Jul 13 14:23     (gnu:0)
+bletch
+@end example
+
+@noindent
+Notice that this program ran the command @code{who} and printed the result.
+(If you try this program yourself, you will get different results, showing
+you who is logged in on your system.)
+
+This variation of @code{getline} splits the record into fields, sets the
+value of @code{NF} and recomputes the value of @code{$0}.  The values of
+@code{NR} and @code{FNR} are not changed.
+
+@item @var{command} | getline @var{var}
+The output of the command @var{command} is sent through a pipe to
+@code{getline} and into the variable @var{var}.  For example, the
+following program reads the current date and time into the variable
+@code{current_time}, using the @code{date} utility, and then
+prints it.@refill
+
+@example
+awk 'BEGIN @{
+     "date" | getline current_time
+     close("date")
+     print "Report printed on " current_time
+@}'
+@end example
+
+In this version of @code{getline}, none of the built-in variables are
+changed, and the record is not split into fields.
+@end table
+
+@node Close Input,  , Getline, Reading Files
+@section Closing Input Files and Pipes
+@cindex closing input files and pipes
+@findex close
+
+If the same file name or the same shell command is used with
+@code{getline} more than once during the execution of an @code{awk}
+program, the file is opened (or the command is executed) only the first time.
+At that time, the first record of input is read from that file or command.
+The next time the same file or command is used in @code{getline}, another
+record is read from it, and so on.
+
+This implies that if you want to start reading the same file again from
+the beginning, or if you want to rerun a shell command (rather than
+reading more output from the command), you must take special steps.
+What you must do is use the @code{close} function, as follows:
+
+@example
+close(@var{filename})
+@end example
+
+@noindent
+or
+
+@example
+close(@var{command})
+@end example
+
+The argument @var{filename} or @var{command} can be any expression.  Its
+value must exactly equal the string that was used to open the file or
+start the command---for example, if you open a pipe with this:
+
+@example
+"sort -r names" | getline foo
+@end example
+
+@noindent
+then you must close it with this:
+
+@example
+close("sort -r names")
+@end example
+
+Once this function call is executed, the next @code{getline} from that
+file or command will reopen the file or rerun the command.
+
+@iftex
+@vindex ERRNO
+@cindex differences: @code{gawk} and @code{awk}
+@end iftex
+@code{close} returns a value of zero if the close succeeded.
+Otherwise, the value will be non-zero.
+In this case, @code{gawk} sets the variable @code{ERRNO} to a string
+describing the error that occurred.
+
+@node Printing, One-liners, Reading Files, Top
+@chapter Printing Output
+
+@cindex printing
+@cindex output
+One of the most common things that actions do is to output or @dfn{print}
+some or all of the input.  For simple output, use the @code{print}
+statement.  For fancier formatting use the @code{printf} statement.
+Both are described in this chapter.
+
+@menu
+* Print::                       The @code{print} statement.
+* Print Examples::              Simple examples of @code{print} statements.
+* Output Separators::           The output separators and how to change them.
+* OFMT::                        Controlling Numeric Output With @code{print}.
+* Printf::                      The @code{printf} statement.
+* Redirection::                 How to redirect output to multiple
+                                files and pipes.
+* Special Files::               File name interpretation in @code{gawk}.
+                                @code{gawk} allows access to 
+                                inherited file descriptors.
+@end menu
+
+@node Print, Print Examples, Printing, Printing
+@section The @code{print} Statement
+@cindex @code{print} statement
+
+The @code{print} statement does output with simple, standardized
+formatting.  You specify only the strings or numbers to be printed, in a
+list separated by commas.  They are output, separated by single spaces,
+followed by a newline.  The statement looks like this:
+
+@example
+print @var{item1}, @var{item2}, @dots{}
+@end example
+
+@noindent
+The entire list of items may optionally be enclosed in parentheses.  The
+parentheses are necessary if any of the item expressions uses a
+relational operator; otherwise it could be confused with a redirection
+(@pxref{Redirection, ,Redirecting Output of @code{print} and @code{printf}}).
+The relational operators are @samp{==},
+@samp{!=}, @samp{<}, @samp{>}, @samp{>=}, @samp{<=}, @samp{~} and
+@samp{!~} (@pxref{Comparison Ops, ,Comparison Expressions}).@refill
+
+The items printed can be constant strings or numbers, fields of the
+current record (such as @code{$1}), variables, or any @code{awk}
+expressions.  The @code{print} statement is completely general for
+computing @emph{what} values to print.  With two exceptions,
+you cannot specify @emph{how} to print them---how many
+columns, whether to use exponential notation or not, and so on.
+(@xref{Output Separators}, and
+@ref{OFMT, ,Controlling Numeric Output with @code{print}}.)
+For that, you need the @code{printf} statement
+(@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing}).@refill
+
+The simple statement @samp{print} with no items is equivalent to
+@samp{print $0}: it prints the entire current record.  To print a blank
+line, use @samp{print ""}, where @code{""} is the null, or empty,
+string.
+
+To print a fixed piece of text, use a string constant such as
+@w{@code{"Hello there"}} as one item.  If you forget to use the
+double-quote characters, your text will be taken as an @code{awk}
+expression, and you will probably get an error.  Keep in mind that a
+space is printed between any two items.
+
+Most often, each @code{print} statement makes one line of output.  But it
+isn't limited to one line.  If an item value is a string that contains a
+newline, the newline is output along with the rest of the string.  A
+single @code{print} can make any number of lines this way.
+
+@node Print Examples, Output Separators, Print, Printing
+@section Examples of @code{print} Statements
+
+Here is an example of printing a string that contains embedded newlines:
+
+@example
+awk 'BEGIN @{ print "line one\nline two\nline three" @}'
+@end example
+
+@noindent
+produces output like this:
+
+@example
+line one
+line two
+line three
+@end example
+
+Here is an example that prints the first two fields of each input record,
+with a space between them:
+
+@example
+awk '@{ print $1, $2 @}' inventory-shipped
+@end example
+
+@noindent
+Its output looks like this:
+
+@example
+Jan 13
+Feb 15
+Mar 15
+@dots{}
+@end example
+
+A common mistake in using the @code{print} statement is to omit the comma
+between two items.  This often has the effect of making the items run
+together in the output, with no space.  The reason for this is that
+juxtaposing two string expressions in @code{awk} means to concatenate
+them.  For example, without the comma:
+
+@example
+awk '@{ print $1 $2 @}' inventory-shipped
+@end example
+
+@noindent
+prints:
+
+@example
+@group
+Jan13
+Feb15
+Mar15
+@dots{}
+@end group
+@end example
+
+Neither example's output makes much sense to someone unfamiliar with the
+file @file{inventory-shipped}.  A heading line at the beginning would make
+it clearer.  Let's add some headings to our table of months (@code{$1}) and
+green crates shipped (@code{$2}).  We do this using the @code{BEGIN} pattern
+(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}) to force the headings to be printed only once:
+
+@example
+awk 'BEGIN @{  print "Month Crates"
+              print "----- ------" @}
+           @{  print $1, $2 @}' inventory-shipped
+@end example
+
+@noindent
+Did you already guess what happens?  This program prints the following:
+
+@example
+@group
+Month Crates
+----- ------
+Jan 13
+Feb 15
+Mar 15
+@dots{}
+@end group
+@end example
+
+@noindent
+The headings and the table data don't line up!  We can fix this by printing
+some spaces between the two fields:
+
+@example
+awk 'BEGIN @{ print "Month Crates"
+             print "----- ------" @}
+           @{ print $1, "     ", $2 @}' inventory-shipped
+@end example
+
+You can imagine that this way of lining up columns can get pretty
+complicated when you have many columns to fix.  Counting spaces for two
+or three columns can be simple, but more than this and you can get
+``lost'' quite easily.  This is why the @code{printf} statement was
+created (@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing});
+one of its specialties is lining up columns of data.@refill
+
+@node Output Separators, OFMT, Print Examples, Printing
+@section Output Separators
+
+@cindex output field separator, @code{OFS}
+@vindex OFS
+@vindex ORS
+@cindex output record separator, @code{ORS}
+As mentioned previously, a @code{print} statement contains a list
+of items, separated by commas.  In the output, the items are normally
+separated by single spaces.  But they do not have to be spaces; a
+single space is only the default.  You can specify any string of
+characters to use as the @dfn{output field separator} by setting the
+built-in variable @code{OFS}.  The initial value of this variable
+is the string @w{@code{" "}}, that is, just a single space.@refill
+
+The output from an entire @code{print} statement is called an
+@dfn{output record}.  Each @code{print} statement outputs one output
+record and then outputs a string called the @dfn{output record separator}.
+The built-in variable @code{ORS} specifies this string.  The initial
+value of the variable is the string @code{"\n"} containing a newline
+character; thus, normally each @code{print} statement makes a separate line.
+
+You can change how output fields and records are separated by assigning
+new values to the variables @code{OFS} and/or @code{ORS}.  The usual
+place to do this is in the @code{BEGIN} rule
+(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}), so
+that it happens before any input is processed.  You may also do this
+with assignments on the command line, before the names of your input
+files.@refill
+
+The following example prints the first and second fields of each input
+record separated by a semicolon, with a blank line added after each
+line:@refill
+
+@example
+@group
+awk 'BEGIN @{ OFS = ";"; ORS = "\n\n" @}
+           @{ print $1, $2 @}'  BBS-list
+@end group
+@end example
+
+If the value of @code{ORS} does not contain a newline, all your output
+will be run together on a single line, unless you output newlines some
+other way.
+
+@node OFMT, Printf, Output Separators, Printing
+@section Controlling Numeric Output with @code{print}
+@vindex OFMT
+When you use the @code{print} statement to print numeric values,
+@code{awk} internally converts the number to a string of characters,
+and prints that string.  @code{awk} uses the @code{sprintf} function
+to do this conversion.  For now, it suffices to say that the @code{sprintf}
+function accepts a @dfn{format specification} that tells it how to format
+numbers (or strings), and that there are a number of different ways that
+numbers can be formatted.  The different format specifications are discussed
+more fully in
+@ref{Printf, ,Using @code{printf} Statements for Fancier Printing}.@refill
+
+The built-in variable @code{OFMT} contains the default format specification
+that @code{print} uses with @code{sprintf} when it wants to convert a
+number to a string for printing.  By supplying different format specifications
+as the value of @code{OFMT}, you can change how @code{print} will print
+your numbers.  As a brief example:
+
+@example
+@group
+awk 'BEGIN @{ OFMT = "%d"  # print numbers as integers
+             print 17.23 @}'
+@end group
+@end example
+
+@noindent
+will print @samp{17}.
+
+@node Printf, Redirection, OFMT, Printing
+@section Using @code{printf} Statements for Fancier Printing
+@cindex formatted output
+@cindex output, formatted
+
+If you want more precise control over the output format than
+@code{print} gives you, use @code{printf}.  With @code{printf} you can
+specify the width to use for each item, and you can specify various
+stylistic choices for numbers (such as what radix to use, whether to
+print an exponent, whether to print a sign, and how many digits to print
+after the decimal point).  You do this by specifying a string, called
+the @dfn{format string}, which controls how and where to print the other
+arguments.
+
+@menu
+* Basic Printf::                Syntax of the @code{printf} statement.
+* Control Letters::             Format-control letters.
+* Format Modifiers::            Format-specification modifiers.
+* Printf Examples::             Several examples.
+@end menu
+
+@node Basic Printf, Control Letters, Printf, Printf
+@subsection Introduction to the @code{printf} Statement
+
+@cindex @code{printf} statement, syntax of
+The @code{printf} statement looks like this:@refill
+
+@example
+printf @var{format}, @var{item1}, @var{item2}, @dots{}
+@end example
+
+@noindent
+The entire list of arguments may optionally be enclosed in parentheses.  The
+parentheses are necessary if any of the item expressions uses a
+relational operator; otherwise it could be confused with a redirection
+(@pxref{Redirection, ,Redirecting Output of @code{print} and @code{printf}}).
+The relational operators are @samp{==},
+@samp{!=}, @samp{<}, @samp{>}, @samp{>=}, @samp{<=}, @samp{~} and
+@samp{!~} (@pxref{Comparison Ops, ,Comparison Expressions}).@refill
+
+@cindex format string
+The difference between @code{printf} and @code{print} is the argument
+@var{format}.  This is an expression whose value is taken as a string; it
+specifies how to output each of the other arguments.  It is called
+the @dfn{format string}.
+
+The format string is the same as in the @sc{ansi} C library function
+@code{printf}.  Most of @var{format} is text to be output verbatim.
+Scattered among this text are @dfn{format specifiers}, one per item.
+Each format specifier says to output the next item at that place in the
+format.@refill
+
+The @code{printf} statement does not automatically append a newline to its
+output.  It outputs only what the format specifies.  So if you want
+a newline, you must include one in the format.  The output separator
+variables @code{OFS} and @code{ORS} have no effect on @code{printf}
+statements.@refill
+
+@node Control Letters, Format Modifiers, Basic Printf, Printf
+@subsection Format-Control Letters
+@cindex @code{printf}, format-control characters
+@cindex format specifier
+
+A format specifier starts with the character @samp{%} and ends with a
+@dfn{format-control letter}; it tells the @code{printf} statement how
+to output one item.  (If you actually want to output a @samp{%}, write
+@samp{%%}.)  The format-control letter specifies what kind of value to
+print.  The rest of the format specifier is made up of optional
+@dfn{modifiers} which are parameters such as the field width to use.@refill
+
+Here is a list of the format-control letters:
+
+@table @samp
+@item c
+This prints a number as an ASCII character.  Thus, @samp{printf "%c",
+65} outputs the letter @samp{A}.  The output for a string value is
+the first character of the string.
+
+@item d
+This prints a decimal integer.
+
+@item i
+This also prints a decimal integer.
+
+@item e
+This prints a number in scientific (exponential) notation.
+For example,
+
+@example
+printf "%4.3e", 1950
+@end example
+
+@noindent
+prints @samp{1.950e+03}, with a total of four significant figures of
+which three follow the decimal point.  The @samp{4.3} are @dfn{modifiers},
+discussed below.
+
+@item f
+This prints a number in floating point notation.
+
+@item g
+This prints a number in either scientific notation or floating point
+notation, whichever uses fewer characters.
+@ignore
+From: gatech!ames!elroy!cit-vax!EQL.Caltech.Edu!rankin (Pat Rankin)
+
+In the description of printf formats (p.43), the information for %g
+is incorrect (mainly, it's too much of an oversimplification).  It's
+wrong in the AWK book too, and in the gawk man page.  I suggested to
+David Trueman before 2.13 was released that the latter be revised, so
+that it matched gawk's behavior (rather than trying to change gawk to
+match the docs ;-).  The documented description is nice and simple, but
+it doesn't match the actual underlying behavior of %g in the various C
+run-time libraries that gawk relies on.  The precision value for g format
+is different than for f and e formats, so it's inaccurate to say 'g' is
+the shorter of 'e' or 'f'.  For 'g', precision represents the number of
+significant digits rather than the number of decimal places, and it has
+special rules about how to format numbers with range between 10E-1 and
+10E-4.  All in all, it's pretty messy, and I had to add that clumsy
+GFMT_WORKAROUND code because the VMS run-time library doesn't conform to
+the ANSI-C specifications.
+@end ignore
+
+@item o
+This prints an unsigned octal integer.
+
+@item s
+This prints a string.
+
+@item x
+This prints an unsigned hexadecimal integer.
+
+@item X
+This prints an unsigned hexadecimal integer.  However, for the values 10
+through 15, it uses the letters @samp{A} through @samp{F} instead of
+@samp{a} through @samp{f}.
+
+@item %
+This isn't really a format-control letter, but it does have a meaning
+when used after a @samp{%}: the sequence @samp{%%} outputs one
+@samp{%}.  It does not consume an argument.
+@end table
+
+@node Format Modifiers, Printf Examples, Control Letters, Printf
+@subsection Modifiers for @code{printf} Formats
+
+@cindex @code{printf}, modifiers
+@cindex modifiers (in format specifiers)
+A format specification can also include @dfn{modifiers} that can control
+how much of the item's value is printed and how much space it gets.  The
+modifiers come between the @samp{%} and the format-control letter.  Here
+are the possible modifiers, in the order in which they may appear:
+
+@table @samp
+@item -
+The minus sign, used before the width modifier, says to left-justify
+the argument within its specified width.  Normally the argument
+is printed right-justified in the specified width.  Thus,
+
+@example
+printf "%-4s", "foo"
+@end example
+
+@noindent
+prints @samp{foo }.
+
+@item @var{width}
+This is a number representing the desired width of a field.  Inserting any
+number between the @samp{%} sign and the format control character forces the
+field to be expanded to this width.  The default way to do this is to
+pad with spaces on the left.  For example,
+
+@example
+printf "%4s", "foo"
+@end example
+
+@noindent
+prints @samp{ foo}.
+
+The value of @var{width} is a minimum width, not a maximum.  If the item
+value requires more than @var{width} characters, it can be as wide as
+necessary.  Thus,
+
+@example
+printf "%4s", "foobar"
+@end example
+
+@noindent
+prints @samp{foobar}.
+
+Preceding the @var{width} with a minus sign causes the output to be
+padded with spaces on the right, instead of on the left.
+
+@item .@var{prec}
+This is a number that specifies the precision to use when printing.
+This specifies the number of digits you want printed to the right of the
+decimal point.  For a string, it specifies the maximum number of
+characters from the string that should be printed.
+@end table
+
+The C library @code{printf}'s dynamic @var{width} and @var{prec}
+capability (for example, @code{"%*.*s"}) is supported.  Instead of
+supplying explicit @var{width} and/or @var{prec} values in the format
+string, you pass them in the argument list.  For example:@refill
+
+@example
+w = 5
+p = 3
+s = "abcdefg"
+printf "<%*.*s>\n", w, p, s
+@end example
+
+@noindent
+is exactly equivalent to
+
+@example
+s = "abcdefg"
+printf "<%5.3s>\n", s
+@end example
+
+@noindent
+Both programs output @samp{@w{<@bullet{}@bullet{}abc>}}.  (We have
+used the bullet symbol ``@bullet{}'' to represent a space, to clearly
+show you that there are two spaces in the output.)@refill
+
+Earlier versions of @code{awk} did not support this capability.  You may
+simulate it by using concatenation to build up the format string,
+like so:@refill
+
+@example
+w = 5
+p = 3
+s = "abcdefg"
+printf "<%" w "." p "s>\n", s
+@end example
+
+@noindent
+This is not particularly easy to read, however.
+
+@node Printf Examples,  , Format Modifiers, Printf
+@subsection Examples of Using @code{printf}
+
+Here is how to use @code{printf} to make an aligned table:
+
+@example
+awk '@{ printf "%-10s %s\n", $1, $2 @}' BBS-list
+@end example
+
+@noindent
+prints the names of bulletin boards (@code{$1}) of the file
+@file{BBS-list} as a string of 10 characters, left justified.  It also
+prints the phone numbers (@code{$2}) afterward on the line.  This
+produces an aligned two-column table of names and phone numbers:@refill
+
+@example
+@group
+aardvark   555-5553
+alpo-net   555-3412
+barfly     555-7685
+bites      555-1675
+camelot    555-0542
+core       555-2912
+fooey      555-1234
+foot       555-6699
+macfoo     555-6480
+sdace      555-3430
+sabafoo    555-2127
+@end group
+@end example
+
+Did you notice that we did not specify that the phone numbers be printed
+as numbers?  They had to be printed as strings because the numbers are
+separated by a dash.  This dash would be interpreted as a minus sign if
+we had tried to print the phone numbers as numbers.  This would have led
+to some pretty confusing results.
+
+We did not specify a width for the phone numbers because they are the
+last things on their lines.  We don't need to put spaces after them.
+
+We could make our table look even nicer by adding headings to the tops
+of the columns.  To do this, use the @code{BEGIN} pattern
+(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns})
+to force the header to be printed only once, at the beginning of
+the @code{awk} program:@refill
+
+@example
+@group
+awk 'BEGIN @{ print "Name      Number"
+             print "----      ------" @}
+     @{ printf "%-10s %s\n", $1, $2 @}' BBS-list
+@end group
+@end example
+
+Did you notice that we mixed @code{print} and @code{printf} statements in
+the above example?  We could have used just @code{printf} statements to get
+the same results:
+
+@example
+@group
+awk 'BEGIN @{ printf "%-10s %s\n", "Name", "Number"
+             printf "%-10s %s\n", "----", "------" @}
+     @{ printf "%-10s %s\n", $1, $2 @}' BBS-list
+@end group
+@end example
+
+@noindent
+By outputting each column heading with the same format specification
+used for the elements of the column, we have made sure that the headings
+are aligned just like the columns.
+
+The fact that the same format specification is used three times can be
+emphasized by storing it in a variable, like this:
+
+@example
+awk 'BEGIN @{ format = "%-10s %s\n"
+             printf format, "Name", "Number"
+             printf format, "----", "------" @}
+     @{ printf format, $1, $2 @}' BBS-list
+@end example
+
+See if you can use the @code{printf} statement to line up the headings and
+table data for our @file{inventory-shipped} example covered earlier in the
+section on the @code{print} statement
+(@pxref{Print, ,The @code{print} Statement}).@refill
+
+@node Redirection, Special Files, Printf, Printing
+@section Redirecting Output of @code{print} and @code{printf}
+
+@cindex output redirection
+@cindex redirection of output
+So far we have been dealing only with output that prints to the standard
+output, usually your terminal.  Both @code{print} and @code{printf} can
+also send their output to other places.
+This is called @dfn{redirection}.@refill
+
+A redirection appears after the @code{print} or @code{printf} statement.
+Redirections in @code{awk} are written just like redirections in shell
+commands, except that they are written inside the @code{awk} program.
+
+@menu
+* File/Pipe Redirection::       Redirecting Output to Files and Pipes.
+* Close Output::                How to close output files and pipes.
+@end menu
+
+@node File/Pipe Redirection, Close Output, Redirection, Redirection
+@subsection Redirecting Output to Files and Pipes
+
+Here are the three forms of output redirection.  They are all shown for
+the @code{print} statement, but they work identically for @code{printf}
+also.@refill
+
+@table @code
+@item print @var{items} > @var{output-file}
+This type of redirection prints the items onto the output file
+@var{output-file}.  The file name @var{output-file} can be any
+expression.  Its value is changed to a string and then used as a
+file name (@pxref{Expressions, ,Expressions as Action Statements}).@refill
+
+When this type of redirection is used, the @var{output-file} is erased
+before the first output is written to it.  Subsequent writes do not
+erase @var{output-file}, but append to it.  If @var{output-file} does
+not exist, then it is created.@refill
+
+For example, here is how one @code{awk} program can write a list of
+BBS names to a file @file{name-list} and a list of phone numbers to a
+file @file{phone-list}.  Each output file contains one name or number
+per line.
+
+@smallexample
+awk '@{ print $2 > "phone-list"
+       print $1 > "name-list" @}' BBS-list
+@end smallexample
+
+@item print @var{items} >> @var{output-file}
+This type of redirection prints the items onto the output file
+@var{output-file}.  The difference between this and the
+single-@samp{>} redirection is that the old contents (if any) of
+@var{output-file} are not erased.  Instead, the @code{awk} output is
+appended to the file.
+
+@cindex pipes for output
+@cindex output, piping
+@item print @var{items} | @var{command}
+It is also possible to send output through a @dfn{pipe} instead of into a
+file.   This type of redirection opens a pipe to @var{command} and writes
+the values of @var{items} through this pipe, to another process created
+to execute @var{command}.@refill
+
+The redirection argument @var{command} is actually an @code{awk}
+expression.  Its value is converted to a string, whose contents give the
+shell command to be run.
+
+For example, this produces two files, one unsorted list of BBS names
+and one list sorted in reverse alphabetical order:
+
+@smallexample
+awk '@{ print $1 > "names.unsorted"
+       print $1 | "sort -r > names.sorted" @}' BBS-list
+@end smallexample
+
+Here the unsorted list is written with an ordinary redirection while
+the sorted list is written by piping through the @code{sort} utility.
+
+Here is an example that uses redirection to mail a message to a mailing
+list @samp{bug-system}.  This might be useful when trouble is encountered
+in an @code{awk} script run periodically for system maintenance.
+
+@smallexample
+report = "mail bug-system"
+print "Awk script failed:", $0 | report
+print "at record number", FNR, "of", FILENAME  | report
+close(report)
+@end smallexample
+
+We call the @code{close} function here because it's a good idea to close
+the pipe as soon as all the intended output has been sent to it.
+@xref{Close Output, ,Closing Output Files and Pipes}, for more information
+on this.  This example also illustrates the use of a variable to represent
+a @var{file} or @var{command}: it is not necessary to always
+use a string constant.  Using a variable is generally a good idea,
+since @code{awk} requires you to spell the string value identically
+every time.
+@end table
+
+Redirecting output using @samp{>}, @samp{>>}, or @samp{|} asks the system
+to open a file or pipe only if the particular @var{file} or @var{command}
+you've specified has not already been written to by your program, or if
+it has been closed since it was last written to.@refill
+
+@node Close Output,  , File/Pipe Redirection, Redirection
+@subsection Closing Output Files and Pipes
+@cindex closing output files and pipes
+@findex close
+
+When a file or pipe is opened, the file name or command associated with
+it is remembered by @code{awk} and subsequent writes to the same file or
+command are appended to the previous writes.  The file or pipe stays
+open until @code{awk} exits.  This is usually convenient.
+
+Sometimes there is a reason to close an output file or pipe earlier
+than that.  To do this, use the @code{close} function, as follows:
+
+@example
+close(@var{filename})
+@end example
+
+@noindent
+or
+
+@example
+close(@var{command})
+@end example
+
+The argument @var{filename} or @var{command} can be any expression.
+Its value must exactly equal the string used to open the file or pipe
+to begin with---for example, if you open a pipe with this:
+
+@example
+print $1 | "sort -r > names.sorted"
+@end example
+
+@noindent
+then you must close it with this:
+
+@example
+close("sort -r > names.sorted")
+@end example
+
+Here are some reasons why you might need to close an output file:
+
+@itemize @bullet
+@item
+To write a file and read it back later on in the same @code{awk}
+program.  Close the file when you are finished writing it; then
+you can start reading it with @code{getline}
+(@pxref{Getline, ,Explicit Input with @code{getline}}).@refill
+
+@item
+To write numerous files, successively, in the same @code{awk}
+program.  If you don't close the files, eventually you may exceed a
+system limit on the number of open files in one process.  So close
+each one when you are finished writing it.
+
+@item
+To make a command finish.  When you redirect output through a pipe,
+the command reading the pipe normally continues to try to read input
+as long as the pipe is open.  Often this means the command cannot
+really do its work until the pipe is closed.  For example, if you
+redirect output to the @code{mail} program, the message is not
+actually sent until the pipe is closed.
+
+@item
+To run the same program a second time, with the same arguments.
+This is not the same thing as giving more input to the first run!
+
+For example, suppose you pipe output to the @code{mail} program.  If you
+output several lines redirected to this pipe without closing it, they make
+a single message of several lines.  By contrast, if you close the pipe
+after each line of output, then each line makes a separate message.
+@end itemize
+
+@iftex
+@vindex ERRNO
+@cindex differences: @code{gawk} and @code{awk}
+@end iftex
+@code{close} returns a value of zero if the close succeeded.
+Otherwise, the value will be non-zero.
+In this case, @code{gawk} sets the variable @code{ERRNO} to a string
+describing the error that occurred.
+
+@node Special Files,  , Redirection, Printing
+@section Standard I/O Streams
+@cindex standard input
+@cindex standard output
+@cindex standard error output
+@cindex file descriptors
+
+Running programs conventionally have three input and output streams
+already available to them for reading and writing.  These are known as
+the @dfn{standard input}, @dfn{standard output}, and @dfn{standard error
+output}.  These streams are, by default, terminal input and output, but
+they are often redirected with the shell, via the @samp{<}, @samp{<<},
+@samp{>}, @samp{>>}, @samp{>&} and @samp{|} operators.  Standard error
+is used only for writing error messages; the reason we have two separate
+streams, standard output and standard error, is so that they can be
+redirected separately.
+
+@iftex
+@cindex differences: @code{gawk} and @code{awk}
+@end iftex
+In other implementations of @code{awk}, the only way to write an error
+message to standard error in an @code{awk} program is as follows:
+
+@smallexample
+print "Serious error detected!\n" | "cat 1>&2"
+@end smallexample
+
+@noindent
+This works by opening a pipeline to a shell command which can access the
+standard error stream which it inherits from the @code{awk} process.
+This is far from elegant, and is also inefficient, since it requires a
+separate process.  So people writing @code{awk} programs have often
+neglected to do this.  Instead, they have sent the error messages to the
+terminal, like this:
+
+@smallexample
+@group
+NF != 4 @{
+   printf("line %d skipped: doesn't have 4 fields\n", FNR) > "/dev/tty"
+@}
+@end group
+@end smallexample
+
+@noindent
+This has the same effect most of the time, but not always: although the
+standard error stream is usually the terminal, it can be redirected, and
+when that happens, writing to the terminal is not correct.  In fact, if
+@code{awk} is run from a background job, it may not have a terminal at all.
+Then opening @file{/dev/tty} will fail.
+
+@code{gawk} provides special file names for accessing the three standard
+streams.  When you redirect input or output in @code{gawk}, if the file name
+matches one of these special names, then @code{gawk} directly uses the
+stream it stands for.
+
+@cindex @file{/dev/stdin}
+@cindex @file{/dev/stdout}
+@cindex @file{/dev/stderr}
+@cindex @file{/dev/fd/}
+@table @file
+@item /dev/stdin
+The standard input (file descriptor 0).
+
+@item /dev/stdout
+The standard output (file descriptor 1).
+
+@item /dev/stderr
+The standard error output (file descriptor 2).
+
+@item /dev/fd/@var{N}
+The file associated with file descriptor @var{N}.  Such a file must have
+been opened by the program initiating the @code{awk} execution (typically
+the shell).  Unless you take special pains, only descriptors 0, 1 and 2
+are available.
+@end table
+
+The file names @file{/dev/stdin}, @file{/dev/stdout}, and @file{/dev/stderr}
+are aliases for @file{/dev/fd/0}, @file{/dev/fd/1}, and @file{/dev/fd/2},
+respectively, but they are more self-explanatory.
+
+The proper way to write an error message in a @code{gawk} program
+is to use @file{/dev/stderr}, like this:
+
+@smallexample
+NF != 4 @{
+  printf("line %d skipped: doesn't have 4 fields\n", FNR) > "/dev/stderr"
+@}
+@end smallexample
+
+@code{gawk} also provides special file names that give access to information
+about the running @code{gawk} process.  Each of these ``files'' provides
+a single record of information.  To read them more than once, you must
+first close them with the @code{close} function
+(@pxref{Close Input, ,Closing Input Files and Pipes}).
+The filenames are:
+
+@cindex @file{/dev/pid}
+@cindex @file{/dev/pgrpid}
+@cindex @file{/dev/ppid}
+@cindex @file{/dev/user}
+@table @file
+@item /dev/pid
+Reading this file returns the process ID of the current process,
+in decimal, terminated with a newline.
+
+@item  /dev/ppid
+Reading this file returns the parent process ID of the current process,
+in decimal, terminated with a newline.
+
+@item  /dev/pgrpid
+Reading this file returns the process group ID of the current process,
+in decimal, terminated with a newline.
+
+@item /dev/user
+Reading this file returns a single record terminated with a newline.
+The fields are separated with blanks.  The fields represent the
+following information:
+
+@table @code
+@item $1
+The value of the @code{getuid} system call.
+
+@item $2
+The value of the @code{geteuid} system call.
+
+@item $3
+The value of the @code{getgid} system call.
+
+@item $4
+The value of the @code{getegid} system call.
+@end table
+
+If there are any additional fields, they are the group IDs returned by
+@code{getgroups} system call.
+(Multiple groups may not be supported on all systems.)@refill
+@end table
+
+These special file names may be used on the command line as data
+files, as well as for I/O redirections within an @code{awk} program.
+They may not be used as source files with the @samp{-f} option.
+
+Recognition of these special file names is disabled if @code{gawk} is in
+compatibility mode (@pxref{Command Line, ,Invoking @code{awk}}).
+
+@quotation
+@strong{Caution}:  Unless your system actually has a @file{/dev/fd} directory
+(or any of the other above listed special files),
+the interpretation of these file names is done by @code{gawk} itself.
+For example, using @samp{/dev/fd/4} for output will actually write on
+file descriptor 4, and not on a new file descriptor that was @code{dup}'ed
+from file descriptor 4.  Most of the time this does not matter; however, it
+is important to @emph{not} close any of the files related to file descriptors
+0, 1, and 2.  If you do close one of these files, unpredictable behavior
+will result.
+@end quotation
+
+@node One-liners, Patterns, Printing, Top
+@chapter Useful ``One-liners''
+
+@cindex one-liners
+Useful @code{awk} programs are often short, just a line or two.  Here is a
+collection of useful, short programs to get you started.  Some of these
+programs contain constructs that haven't been covered yet.  The description
+of the program will give you a good idea of what is going on, but please
+read the rest of the manual to become an @code{awk} expert!
+
+@c Per suggestions from Michal Jaegermann
+@ifinfo
+Since you are reading this in Info, each line of the example code is
+enclosed in quotes, to represent text that you would type literally.
+The examples themselves represent shell commands that use single quotes
+to keep the shell from interpreting the contents of the program.
+When reading the examples, focus on the text between the open and close
+quotes.
+@end ifinfo
+
+@table @code
+@item awk '@{ if (NF > max) max = NF @}
+@itemx @ @ @ @ @ END @{ print max @}'
+This program prints the maximum number of fields on any input line.
+
+@item awk 'length($0) > 80'
+This program prints every line longer than 80 characters.  The sole
+rule has a relational expression as its pattern, and has no action (so the
+default action, printing the record, is used).
+
+@item awk 'NF > 0'
+This program prints every line that has at least one field.  This is an
+easy way to delete blank lines from a file (or rather, to create a new
+file similar to the old file but from which the blank lines have been
+deleted).
+
+@item awk '@{ if (NF > 0) print @}'
+This program also prints every line that has at least one field.  Here we
+allow the rule to match every line, then decide in the action whether
+to print.
+
+@item awk@ 'BEGIN@ @{@ for (i = 1; i <= 7; i++)
+@itemx @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ print int(101 * rand()) @}'
+This program prints 7 random numbers from 0 to 100, inclusive.
+
+@item ls -l @var{files} | awk '@{ x += $4 @} ; END @{ print "total bytes: " x @}'
+This program prints the total number of bytes used by @var{files}.
+
+@item expand@ @var{file}@ |@ awk@ '@{ if (x < length()) x = length() @}
+@itemx @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ END @{ print "maximum line length is " x @}'
+This program prints the maximum line length of @var{file}.  The input
+is piped through the @code{expand} program to change tabs into spaces,
+so the widths compared are actually the right-margin columns.
+
+@item awk 'BEGIN @{ FS = ":" @}
+@itemx @ @ @ @ @ @{ print $1 | "sort" @}' /etc/passwd
+This program prints a sorted list of the login names of all users.
+
+@item awk '@{ nlines++ @}
+@itemx @ @ @ @ @ END@ @{ print nlines @}'
+This programs counts lines in a file.
+
+@item awk 'END @{ print NR @}'
+This program also counts lines in a file, but lets @code{awk} do the work.
+
+@item awk '@{ print NR, $0 @}'
+This program adds line numbers to all its input files,
+similar to @samp{cat -n}.
+@end table
+
+@node Patterns, Actions, One-liners, Top
+@chapter Patterns
+@cindex pattern, definition of
+
+Patterns in @code{awk} control the execution of rules: a rule is
+executed when its pattern matches the current input record.  This
+chapter tells all about how to write patterns.
+
+@menu
+* Kinds of Patterns::           A list of all kinds of patterns.
+                                The following subsections describe 
+                                them in detail.
+* Regexp::                      Regular expressions such as @samp{/foo/}.
+* Comparison Patterns::         Comparison expressions such as @code{$1 > 10}.
+* Boolean Patterns::            Combining comparison expressions.
+* Expression Patterns::         Any expression can be used as a pattern.
+* Ranges::                      Pairs of patterns specify record ranges.
+* BEGIN/END::                   Specifying initialization and cleanup rules.
+* Empty::                       The empty pattern, which matches every record.
+@end menu
+
+@node Kinds of Patterns, Regexp, Patterns, Patterns
+@section Kinds of Patterns
+@cindex patterns, types of
+
+Here is a summary of the types of patterns supported in @code{awk}.
+@c At the next rewrite, check to see that this order matches the
+@c order in the text.  It might not matter to a reader, but it's good
+@c style.  Also, it might be nice to mention all the topics of sections
+@c that follow in this list; that way people can scan and know when to
+@c expect a specific topic.  Specifically please also make an entry
+@c for Boolean operators as patterns in the right place.  --mew
+
+@table @code
+@item /@var{regular expression}/
+A regular expression as a pattern.  It matches when the text of the
+input record fits the regular expression.
+(@xref{Regexp, ,Regular Expressions as Patterns}.)@refill
+
+@item @var{expression}
+A single expression.  It matches when its value, converted to a number,
+is nonzero (if a number) or nonnull (if a string).
+(@xref{Expression Patterns, ,Expressions as Patterns}.)@refill
+
+@item @var{pat1}, @var{pat2}
+A pair of patterns separated by a comma, specifying a range of records.
+(@xref{Ranges, ,Specifying Record Ranges with Patterns}.)
+
+@item BEGIN
+@itemx END
+Special patterns to supply start-up or clean-up information to
+@code{awk}.  (@xref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}.)
+
+@item @var{null}
+The empty pattern matches every input record.
+(@xref{Empty, ,The Empty Pattern}.)@refill
+@end table
+
+
+@node Regexp, Comparison Patterns, Kinds of Patterns, Patterns
+@section Regular Expressions as Patterns
+@cindex pattern, regular expressions
+@cindex regexp
+@cindex regular expressions as patterns
+
+A @dfn{regular expression}, or @dfn{regexp}, is a way of describing a
+class of strings.  A regular expression enclosed in slashes (@samp{/})
+is an @code{awk} pattern that matches every input record whose text
+belongs to that class.
+
+The simplest regular expression is a sequence of letters, numbers, or
+both.  Such a regexp matches any string that contains that sequence.
+Thus, the regexp @samp{foo} matches any string containing @samp{foo}.
+Therefore, the pattern @code{/foo/} matches any input record containing
+@samp{foo}.  Other kinds of regexps let you specify more complicated
+classes of strings.
+
+@menu
+* Regexp Usage::                How to Use Regular Expressions
+* Regexp Operators::            Regular Expression Operators
+* Case-sensitivity::            How to do case-insensitive matching.
+@end menu
+
+@node Regexp Usage, Regexp Operators, Regexp, Regexp
+@subsection How to Use Regular Expressions
+
+A regular expression can be used as a pattern by enclosing it in
+slashes.  Then the regular expression is matched against the
+entire text of each record.  (Normally, it only needs
+to match some part of the text in order to succeed.)  For example, this
+prints the second field of each record that contains @samp{foo} anywhere:
+
+@example
+awk '/foo/ @{ print $2 @}' BBS-list
+@end example
+
+@cindex regular expression matching operators
+@cindex string-matching operators
+@cindex operators, string-matching
+@cindex operators, regexp matching
+@cindex regexp search operators
+Regular expressions can also be used in comparison expressions.  Then
+you can specify the string to match against; it need not be the entire
+current input record.  These comparison expressions can be used as
+patterns or in @code{if}, @code{while}, @code{for}, and @code{do} statements.
+
+@table @code
+@item @var{exp} ~ /@var{regexp}/
+This is true if the expression @var{exp} (taken as a character string)
+is matched by @var{regexp}.  The following example matches, or selects,
+all input records with the upper-case letter @samp{J} somewhere in the
+first field:@refill
+
+@example
+awk '$1 ~ /J/' inventory-shipped
+@end example
+
+So does this:
+
+@example
+awk '@{ if ($1 ~ /J/) print @}' inventory-shipped
+@end example
+
+@item @var{exp} !~ /@var{regexp}/
+This is true if the expression @var{exp} (taken as a character string)
+is @emph{not} matched by @var{regexp}.  The following example matches,
+or selects, all input records whose first field @emph{does not} contain
+the upper-case letter @samp{J}:@refill
+
+@example
+awk '$1 !~ /J/' inventory-shipped
+@end example
+@end table
+
+@cindex computed regular expressions
+@cindex regular expressions, computed
+@cindex dynamic regular expressions
+The right hand side of a @samp{~} or @samp{!~} operator need not be a
+constant regexp (i.e., a string of characters between slashes).  It may
+be any expression.  The expression is evaluated, and converted if
+necessary to a string; the contents of the string are used as the
+regexp.  A regexp that is computed in this way is called a @dfn{dynamic
+regexp}.  For example:
+
+@example
+identifier_regexp = "[A-Za-z_][A-Za-z_0-9]+"
+$0 ~ identifier_regexp
+@end example
+
+@noindent
+sets @code{identifier_regexp} to a regexp that describes @code{awk}
+variable names, and tests if the input record matches this regexp.
+
+@node Regexp Operators, Case-sensitivity, Regexp Usage, Regexp
+@subsection Regular Expression Operators
+@cindex metacharacters
+@cindex regular expression metacharacters
+
+You can combine regular expressions with the following characters,
+called @dfn{regular expression operators}, or @dfn{metacharacters}, to
+increase the power and versatility of regular expressions.
+
+Here is a table of metacharacters.  All characters not listed in the
+table stand for themselves.
+
+@table @code
+@item ^
+This matches the beginning of the string or the beginning of a line
+within the string.  For example:
+
+@example
+^@@chapter
+@end example
+
+@noindent
+matches the @samp{@@chapter} at the beginning of a string, and can be used
+to identify chapter beginnings in Texinfo source files.
+
+@item $
+This is similar to @samp{^}, but it matches only at the end of a string
+or the end of a line within the string.  For example:
+
+@example
+p$
+@end example
+
+@noindent
+matches a record that ends with a @samp{p}.
+
+@item .
+This matches any single character except a newline.  For example:
+
+@example
+.P
+@end example
+
+@noindent
+matches any single character followed by a @samp{P} in a string.  Using
+concatenation we can make regular expressions like @samp{U.A}, which
+matches any three-character sequence that begins with @samp{U} and ends
+with @samp{A}.
+
+@item [@dots{}]
+This is called a @dfn{character set}.  It matches any one of the
+characters that are enclosed in the square brackets.  For example:
+
+@example
+[MVX]
+@end example
+
+@noindent
+matches any one of the characters @samp{M}, @samp{V}, or @samp{X} in a
+string.@refill
+
+Ranges of characters are indicated by using a hyphen between the beginning
+and ending characters, and enclosing the whole thing in brackets.  For
+example:@refill
+
+@example
+[0-9]
+@end example
+
+@noindent
+matches any digit.
+
+To include the character @samp{\}, @samp{]}, @samp{-} or @samp{^} in a
+character set, put a @samp{\} in front of it.  For example:
+
+@example
+[d\]]
+@end example
+
+@noindent
+matches either @samp{d}, or @samp{]}.@refill
+
+This treatment of @samp{\} is compatible with other @code{awk}
+implementations, and is also mandated by the @sc{posix} Command Language
+and Utilities standard.  The regular expressions in @code{awk} are a superset
+of the @sc{posix} specification for Extended Regular Expressions (EREs).
+@sc{posix} EREs are based on the regular expressions accepted by the
+traditional @code{egrep} utility.
+
+In @code{egrep} syntax, backslash is not syntactically special within
+square brackets.  This means that special tricks have to be used to
+represent the characters @samp{]}, @samp{-} and @samp{^} as members of a
+character set.
+
+In @code{egrep} syntax, to match @samp{-}, write it as @samp{---},
+which is a range containing only @w{@samp{-}.}  You may also give @samp{-}
+as the first or last character in the set.  To match @samp{^}, put it
+anywhere except as the first character of a set.  To match a @samp{]},
+make it the first character in the set.  For example:@refill
+
+@example
+[]d^]
+@end example
+
+@noindent
+matches either @samp{]}, @samp{d} or @samp{^}.@refill
+
+@item [^ @dots{}]
+This is a @dfn{complemented character set}.  The first character after
+the @samp{[} @emph{must} be a @samp{^}.  It matches any characters
+@emph{except} those in the square brackets (or newline).  For example:
+
+@example
+[^0-9]
+@end example
+
+@noindent
+matches any character that is not a digit.
+
+@item |
+This is the @dfn{alternation operator} and it is used to specify
+alternatives.  For example:
+
+@example
+^P|[0-9]
+@end example
+
+@noindent
+matches any string that matches either @samp{^P} or @samp{[0-9]}.  This
+means it matches any string that contains a digit or starts with @samp{P}.
+
+The alternation applies to the largest possible regexps on either side.
+@item (@dots{})
+Parentheses are used for grouping in regular expressions as in
+arithmetic.  They can be used to concatenate regular expressions
+containing the alternation operator, @samp{|}.
+
+@item *
+This symbol means that the preceding regular expression is to be
+repeated as many times as possible to find a match.  For example:
+
+@example
+ph*
+@end example
+
+@noindent
+applies the @samp{*} symbol to the preceding @samp{h} and looks for matches
+to one @samp{p} followed by any number of @samp{h}s.  This will also match
+just @samp{p} if no @samp{h}s are present.
+
+The @samp{*} repeats the @emph{smallest} possible preceding expression.
+(Use parentheses if you wish to repeat a larger expression.)  It finds
+as many repetitions as possible.  For example:
+
+@example
+awk '/\(c[ad][ad]*r x\)/ @{ print @}' sample
+@end example
+
+@noindent
+prints every record in the input containing a string of the form
+@samp{(car x)}, @samp{(cdr x)}, @samp{(cadr x)}, and so on.@refill
+
+@item +
+This symbol is similar to @samp{*}, but the preceding expression must be
+matched at least once.  This means that:
+
+@example
+wh+y
+@end example
+
+@noindent
+would match @samp{why} and @samp{whhy} but not @samp{wy}, whereas
+@samp{wh*y} would match all three of these strings.  This is a simpler
+way of writing the last @samp{*} example:
+
+@example
+awk '/\(c[ad]+r x\)/ @{ print @}' sample
+@end example
+
+@item ?
+This symbol is similar to @samp{*}, but the preceding expression can be
+matched once or not at all.  For example:
+
+@example
+fe?d
+@end example
+
+@noindent
+will match @samp{fed} and @samp{fd}, but nothing else.@refill
+
+@item \
+This is used to suppress the special meaning of a character when
+matching.  For example:
+
+@example
+\$
+@end example
+
+@noindent
+matches the character @samp{$}.
+
+The escape sequences used for string constants
+(@pxref{Constants, ,Constant Expressions}) are
+valid in regular expressions as well; they are also introduced by a
+@samp{\}.@refill
+@end table
+
+In regular expressions, the @samp{*}, @samp{+}, and @samp{?} operators have
+the highest precedence, followed by concatenation, and finally by @samp{|}.
+As in arithmetic, parentheses can change how operators are grouped.@refill
+
+@node Case-sensitivity,  , Regexp Operators, Regexp
+@subsection Case-sensitivity in Matching
+
+Case is normally significant in regular expressions, both when matching
+ordinary characters (i.e., not metacharacters), and inside character
+sets.  Thus a @samp{w} in a regular expression matches only a lower case
+@samp{w} and not an upper case @samp{W}.
+
+The simplest way to do a case-independent match is to use a character
+set: @samp{[Ww]}.  However, this can be cumbersome if you need to use it
+often; and it can make the regular expressions harder for humans to
+read.  There are two other alternatives that you might prefer.
+
+One way to do a case-insensitive match at a particular point in the
+program is to convert the data to a single case, using the
+@code{tolower} or @code{toupper} built-in string functions (which we
+haven't discussed yet;
+@pxref{String Functions, ,Built-in Functions for String Manipulation}).
+For example:@refill
+
+@example
+tolower($1) ~ /foo/  @{ @dots{} @}
+@end example
+
+@noindent
+converts the first field to lower case before matching against it.
+
+Another method is to set the variable @code{IGNORECASE} to a nonzero
+value (@pxref{Built-in Variables}).  When @code{IGNORECASE} is not zero,
+@emph{all} regexp operations ignore case.  Changing the value of
+@code{IGNORECASE} dynamically controls the case sensitivity of your
+program as it runs.  Case is significant by default because
+@code{IGNORECASE} (like most variables) is initialized to zero.
+
+@example
+x = "aB"
+if (x ~ /ab/) @dots{}   # this test will fail
+
+IGNORECASE = 1
+if (x ~ /ab/) @dots{}   # now it will succeed
+@end example
+
+In general, you cannot use @code{IGNORECASE} to make certain rules
+case-insensitive and other rules case-sensitive, because there is no way
+to set @code{IGNORECASE} just for the pattern of a particular rule.  To
+do this, you must use character sets or @code{tolower}.  However, one
+thing you can do only with @code{IGNORECASE} is turn case-sensitivity on
+or off dynamically for all the rules at once.@refill
+
+@code{IGNORECASE} can be set on the command line, or in a @code{BEGIN}
+rule.  Setting @code{IGNORECASE} from the command line is a way to make
+a program case-insensitive without having to edit it.
+
+The value of @code{IGNORECASE} has no effect if @code{gawk} is in
+compatibility mode (@pxref{Command Line, ,Invoking @code{awk}}).
+Case is always significant in compatibility mode.@refill
+
+@node Comparison Patterns, Boolean Patterns, Regexp, Patterns
+@section Comparison Expressions as Patterns
+@cindex comparison expressions as patterns
+@cindex pattern, comparison expressions
+@cindex relational operators
+@cindex operators, relational
+
+@dfn{Comparison patterns} test relationships such as equality between
+two strings or numbers.  They are a special case of expression patterns
+(@pxref{Expression Patterns, ,Expressions as Patterns}).  They are written
+with @dfn{relational operators}, which are a superset of those in C.
+Here is a table of them:@refill
+
+@table @code
+@item @var{x} < @var{y}
+True if @var{x} is less than @var{y}.
+
+@item @var{x} <= @var{y}
+True if @var{x} is less than or equal to @var{y}.
+
+@item @var{x} > @var{y}
+True if @var{x} is greater than @var{y}.
+
+@item @var{x} >= @var{y}
+True if @var{x} is greater than or equal to @var{y}.
+
+@item @var{x} == @var{y}
+True if @var{x} is equal to @var{y}.
+
+@item @var{x} != @var{y}
+True if @var{x} is not equal to @var{y}.
+
+@item @var{x} ~ @var{y}
+True if @var{x} matches the regular expression described by @var{y}.
+
+@item @var{x} !~ @var{y}
+True if @var{x} does not match the regular expression described by @var{y}.
+@end table
+
+The operands of a relational operator are compared as numbers if they
+are both numbers.  Otherwise they are converted to, and compared as,
+strings (@pxref{Conversion, ,Conversion of Strings and Numbers},
+for the detailed rules).  Strings are compared by comparing the first
+character of each, then the second character of each,
+and so on, until there is a difference.  If the two strings are equal until
+the shorter one runs out, the shorter one is considered to be less than the
+longer one.  Thus, @code{"10"} is less than @code{"9"}, and @code{"abc"}
+is less than @code{"abcd"}.@refill
+
+The left operand of the @samp{~} and @samp{!~} operators is a string.
+The right operand is either a constant regular expression enclosed in
+slashes (@code{/@var{regexp}/}), or any expression, whose string value
+is used as a dynamic regular expression
+(@pxref{Regexp Usage, ,How to Use Regular Expressions}).@refill
+
+The following example prints the second field of each input record
+whose first field is precisely @samp{foo}.
+
+@example
+awk '$1 == "foo" @{ print $2 @}' BBS-list
+@end example
+
+@noindent
+Contrast this with the following regular expression match, which would
+accept any record with a first field that contains @samp{foo}:
+
+@example
+awk '$1 ~ "foo" @{ print $2 @}' BBS-list
+@end example
+
+@noindent
+or, equivalently, this one:
+
+@example
+awk '$1 ~ /foo/ @{ print $2 @}' BBS-list
+@end example
+
+@node Boolean Patterns, Expression Patterns, Comparison Patterns, Patterns
+@section Boolean Operators and Patterns
+@cindex patterns, boolean
+@cindex boolean patterns
+
+A @dfn{boolean pattern} is an expression which combines other patterns
+using the @dfn{boolean operators} ``or'' (@samp{||}), ``and''
+(@samp{&&}), and ``not'' (@samp{!}).  Whether the boolean pattern
+matches an input record depends on whether its subpatterns match.
+
+For example, the following command prints all records in the input file
+@file{BBS-list} that contain both @samp{2400} and @samp{foo}.@refill
+
+@example
+awk '/2400/ && /foo/' BBS-list
+@end example
+
+The following command prints all records in the input file
+@file{BBS-list} that contain @emph{either} @samp{2400} or @samp{foo}, or
+both.@refill
+
+@example
+awk '/2400/ || /foo/' BBS-list
+@end example
+
+The following command prints all records in the input file
+@file{BBS-list} that do @emph{not} contain the string @samp{foo}.
+
+@example
+awk '! /foo/' BBS-list
+@end example
+
+Note that boolean patterns are a special case of expression patterns
+(@pxref{Expression Patterns, ,Expressions as Patterns}); they are
+expressions that use the boolean operators.
+@xref{Boolean Ops, ,Boolean Expressions}, for complete information
+on the boolean operators.@refill
+
+The subpatterns of a boolean pattern can be constant regular
+expressions, comparisons, or any other @code{awk} expressions.  Range
+patterns are not expressions, so they cannot appear inside boolean
+patterns.  Likewise, the special patterns @code{BEGIN} and @code{END},
+which never match any input record, are not expressions and cannot
+appear inside boolean patterns.
+
+@node Expression Patterns, Ranges, Boolean Patterns, Patterns
+@section Expressions as Patterns
+
+Any @code{awk} expression is also valid as an @code{awk} pattern.
+Then the pattern ``matches'' if the expression's value is nonzero (if a
+number) or nonnull (if a string).
+
+The expression is reevaluated each time the rule is tested against a new
+input record.  If the expression uses fields such as @code{$1}, the
+value depends directly on the new input record's text; otherwise, it
+depends only on what has happened so far in the execution of the
+@code{awk} program, but that may still be useful.
+
+Comparison patterns are actually a special case of this.  For
+example, the expression @code{$5 == "foo"} has the value 1 when the
+value of @code{$5} equals @code{"foo"}, and 0 otherwise; therefore, this
+expression as a pattern matches when the two values are equal.
+
+Boolean patterns are also special cases of expression patterns.
+
+A constant regexp as a pattern is also a special case of an expression
+pattern.  @code{/foo/} as an expression has the value 1 if @samp{foo}
+appears in the current input record; thus, as a pattern, @code{/foo/}
+matches any record containing @samp{foo}.
+
+Other implementations of @code{awk} that are not yet @sc{posix} compliant
+are less general than @code{gawk}: they allow comparison expressions, and
+boolean combinations thereof (optionally with parentheses), but not
+necessarily other kinds of expressions.
+
+@node Ranges, BEGIN/END, Expression Patterns, Patterns
+@section Specifying Record Ranges with Patterns
+
+@cindex range pattern
+@cindex patterns, range
+A @dfn{range pattern} is made of two patterns separated by a comma, of
+the form @code{@var{begpat}, @var{endpat}}.  It matches ranges of
+consecutive input records.  The first pattern @var{begpat} controls
+where the range begins, and the second one @var{endpat} controls where
+it ends.  For example,@refill
+
+@example
+awk '$1 == "on", $1 == "off"'
+@end example
+
+@noindent
+prints every record between @samp{on}/@samp{off} pairs, inclusive.
+
+A range pattern starts out by matching @var{begpat}
+against every input record; when a record matches @var{begpat}, the
+range pattern becomes @dfn{turned on}.  The range pattern matches this
+record.  As long as it stays turned on, it automatically matches every
+input record read.  It also matches @var{endpat} against
+every input record; when that succeeds, the range pattern is turned
+off again for the following record.  Now it goes back to checking
+@var{begpat} against each record.
+
+The record that turns on the range pattern and the one that turns it
+off both match the range pattern.  If you don't want to operate on
+these records, you can write @code{if} statements in the rule's action
+to distinguish them.
+
+It is possible for a pattern to be turned both on and off by the same
+record, if both conditions are satisfied by that record.  Then the action is
+executed for just that record.
+
+@node BEGIN/END, Empty, Ranges, Patterns
+@section @code{BEGIN} and @code{END} Special Patterns
+
+@cindex @code{BEGIN} special pattern
+@cindex patterns, @code{BEGIN}
+@cindex @code{END} special pattern
+@cindex patterns, @code{END}
+@code{BEGIN} and @code{END} are special patterns.  They are not used to
+match input records.  Rather, they are used for supplying start-up or
+clean-up information to your @code{awk} script.  A @code{BEGIN} rule is
+executed, once, before the first input record has been read.  An @code{END}
+rule is executed, once, after all the input has been read.  For
+example:@refill
+
+@example
+awk 'BEGIN @{ print "Analysis of `foo'" @}
+     /foo/ @{ ++foobar @}
+     END   @{ print "`foo' appears " foobar " times." @}' BBS-list
+@end example
+
+This program finds the number of records in the input file @file{BBS-list}
+that contain the string @samp{foo}.  The @code{BEGIN} rule prints a title
+for the report.  There is no need to use the @code{BEGIN} rule to
+initialize the counter @code{foobar} to zero, as @code{awk} does this
+for us automatically (@pxref{Variables}).
+
+The second rule increments the variable @code{foobar} every time a
+record containing the pattern @samp{foo} is read.  The @code{END} rule
+prints the value of @code{foobar} at the end of the run.@refill
+
+The special patterns @code{BEGIN} and @code{END} cannot be used in ranges
+or with boolean operators (indeed, they cannot be used with any operators).
+
+An @code{awk} program may have multiple @code{BEGIN} and/or @code{END}
+rules.  They are executed in the order they appear, all the @code{BEGIN}
+rules at start-up and all the @code{END} rules at termination.
+
+Multiple @code{BEGIN} and @code{END} sections are useful for writing
+library functions, since each library can have its own @code{BEGIN} or
+@code{END} rule to do its own initialization and/or cleanup.  Note that
+the order in which library functions are named on the command line
+controls the order in which their @code{BEGIN} and @code{END} rules are
+executed.  Therefore you have to be careful to write such rules in
+library files so that the order in which they are executed doesn't matter.
+@xref{Command Line, ,Invoking @code{awk}}, for more information on
+using library functions.
+
+If an @code{awk} program only has a @code{BEGIN} rule, and no other
+rules, then the program exits after the @code{BEGIN} rule has been run.
+(Older versions of @code{awk} used to keep reading and ignoring input
+until end of file was seen.)  However, if an @code{END} rule exists as
+well, then the input will be read, even if there are no other rules in
+the program.  This is necessary in case the @code{END} rule checks the
+@code{NR} variable.
+
+@code{BEGIN} and @code{END} rules must have actions; there is no default
+action for these rules since there is no current record when they run.
+
+@node Empty,  , BEGIN/END, Patterns
+@comment  node-name,  next,  previous,  up
+@section The Empty Pattern
+
+@cindex empty pattern
+@cindex pattern, empty
+An empty pattern is considered to match @emph{every} input record.  For
+example, the program:@refill
+
+@example
+awk '@{ print $1 @}' BBS-list
+@end example
+
+@noindent
+prints the first field of every record.
+
+@node Actions, Expressions, Patterns, Top
+@chapter Overview of Actions
+@cindex action, definition of
+@cindex curly braces
+@cindex action, curly braces
+@cindex action, separating statements
+
+An @code{awk} program or script consists of a series of
+rules and function definitions, interspersed.  (Functions are
+described later.  @xref{User-defined, ,User-defined Functions}.)
+
+A rule contains a pattern and an action, either of which may be
+omitted.  The purpose of the @dfn{action} is to tell @code{awk} what to do
+once a match for the pattern is found.  Thus, the entire program
+looks somewhat like this:
+
+@example
+@r{[}@var{pattern}@r{]} @r{[}@{ @var{action} @}@r{]}
+@r{[}@var{pattern}@r{]} @r{[}@{ @var{action} @}@r{]}
+@dots{}
+function @var{name} (@var{args}) @{ @dots{} @}
+@dots{}
+@end example
+
+An action consists of one or more @code{awk} @dfn{statements}, enclosed
+in curly braces (@samp{@{} and @samp{@}}).  Each statement specifies one
+thing to be done.  The statements are separated by newlines or
+semicolons.
+
+The curly braces around an action must be used even if the action
+contains only one statement, or even if it contains no statements at
+all.  However, if you omit the action entirely, omit the curly braces as
+well.  (An omitted action is equivalent to @samp{@{ print $0 @}}.)
+
+Here are the kinds of statements supported in @code{awk}:
+
+@itemize @bullet
+@item
+Expressions, which can call functions or assign values to variables
+(@pxref{Expressions, ,Expressions as Action Statements}).  Executing
+this kind of statement simply computes the value of the expression and
+then ignores it.  This is useful when the expression has side effects
+(@pxref{Assignment Ops, ,Assignment Expressions}).@refill
+
+@item
+Control statements, which specify the control flow of @code{awk}
+programs.  The @code{awk} language gives you C-like constructs
+(@code{if}, @code{for}, @code{while}, and so on) as well as a few
+special ones (@pxref{Statements, ,Control Statements in Actions}).@refill
+
+@item
+Compound statements, which consist of one or more statements enclosed in
+curly braces.  A compound statement is used in order to put several
+statements together in the body of an @code{if}, @code{while}, @code{do}
+or @code{for} statement.
+
+@item
+Input control, using the @code{getline} command
+(@pxref{Getline, ,Explicit Input with @code{getline}}), and the @code{next}
+statement (@pxref{Next Statement, ,The @code{next} Statement}).
+
+@item
+Output statements, @code{print} and @code{printf}.
+@xref{Printing, ,Printing Output}.@refill
+
+@item
+Deletion statements, for deleting array elements.
+@xref{Delete, ,The @code{delete} Statement}.@refill
+@end itemize
+
+@iftex
+The next two chapters cover in detail expressions and control
+statements, respectively.  We go on to treat arrays and built-in
+functions, both of which are used in expressions.  Then we proceed
+to discuss how to define your own functions.
+@end iftex
+
+@node Expressions, Statements, Actions, Top
+@chapter Expressions as Action Statements
+@cindex expression
+
+Expressions are the basic building block of @code{awk} actions.  An
+expression evaluates to a value, which you can print, test, store in a
+variable or pass to a function.  But beyond that, an expression can assign a new value to a variable
+or a field, with an assignment operator.
+
+An expression can serve as a statement on its own.  Most other kinds of
+statements contain one or more expressions which specify data to be
+operated on.  As in other languages, expressions in @code{awk} include
+variables, array references, constants, and function calls, as well as
+combinations of these with various operators.
+
+@menu
+* Constants::                   String, numeric, and regexp constants.
+* Variables::                   Variables give names to values for later use.
+* Arithmetic Ops::              Arithmetic operations (@samp{+}, @samp{-}, etc.)
+* Concatenation::               Concatenating strings.
+* Comparison Ops::              Comparison of numbers and strings 
+                                with @samp{<}, etc.
+* Boolean Ops::                 Combining comparison expressions 
+                                using boolean operators
+                                @samp{||} (``or''), @samp{&&} (``and'') and @samp{!} (``not'').
+
+* Assignment Ops::              Changing the value of a variable or a field.
+* Increment Ops::               Incrementing the numeric value of a variable.
+
+* Conversion::                  The conversion of strings to numbers 
+                                and vice versa.
+* Values::                      The whole truth about numbers and strings.
+* Conditional Exp::             Conditional expressions select 
+                                between two subexpressions under control 
+                                of a third subexpression.
+* Function Calls::              A function call is an expression.
+* Precedence::                  How various operators nest.
+@end menu
+
+@node Constants, Variables, Expressions, Expressions
+@section Constant Expressions
+@cindex constants, types of
+@cindex string constants
+
+The simplest type of expression is the @dfn{constant}, which always has
+the same value.  There are three types of constants: numeric constants,
+string constants, and regular expression constants.
+
+@cindex numeric constant
+@cindex numeric value
+A @dfn{numeric constant} stands for a number.  This number can be an
+integer, a decimal fraction, or a number in scientific (exponential)
+notation.  Note that all numeric values are represented within
+@code{awk} in double-precision floating point.  Here are some examples
+of numeric constants, which all have the same value:
+
+@example
+105
+1.05e+2
+1050e-1
+@end example
+
+A string constant consists of a sequence of characters enclosed in
+double-quote marks.  For example:
+
+@example
+"parrot"
+@end example
+
+@noindent
+@iftex
+@cindex differences between @code{gawk} and @code{awk}
+@end iftex
+represents the string whose contents are @samp{parrot}.  Strings in
+@code{gawk} can be of any length and they can contain all the possible
+8-bit ASCII characters including ASCII NUL.  Other @code{awk}
+implementations may have difficulty with some character codes.@refill
+
+@cindex escape sequence notation
+Some characters cannot be included literally in a string constant.  You
+represent them instead with @dfn{escape sequences}, which are character
+sequences beginning with a backslash (@samp{\}).
+
+One use of an escape sequence is to include a double-quote character in
+a string constant.  Since a plain double-quote would end the string, you
+must use @samp{\"} to represent a single double-quote character as a
+part of the string.  
+The 
+backslash character itself is another character that cannot be
+included normally; you write @samp{\\} to put one backslash in the
+string.  Thus, the string whose contents are the two characters
+@samp{"\} must be written @code{"\"\\"}.
+
+Another use of backslash is to represent unprintable characters
+such as newline.  While there is nothing to stop you from writing most
+of these characters directly in a string constant, they may look ugly.
+
+Here is a table of all the escape sequences used in @code{awk}:
+
+@table @code
+@item \\
+Represents a literal backslash, @samp{\}.
+
+@item \a
+Represents the ``alert'' character, control-g, ASCII code 7.
+
+@item \b
+Represents a backspace, control-h, ASCII code 8.
+
+@item \f
+Represents a formfeed, control-l, ASCII code 12.
+
+@item \n
+Represents a newline, control-j, ASCII code 10.
+
+@item \r
+Represents a carriage return, control-m, ASCII code 13.
+
+@item \t
+Represents a horizontal tab, control-i, ASCII code 9.
+
+@item \v
+Represents a vertical tab, control-k, ASCII code 11.
+
+@item \@var{nnn}
+Represents the octal value @var{nnn}, where @var{nnn} are one to three
+digits between 0 and 7.  For example, the code for the ASCII ESC
+(escape) character is @samp{\033}.@refill
+
+@item \x@var{hh}@dots{}
+Represents the hexadecimal value @var{hh}, where @var{hh} are hexadecimal
+digits (@samp{0} through @samp{9} and either @samp{A} through @samp{F} or
+@samp{a} through @samp{f}).  Like the same construct in @sc{ansi} C, the escape
+sequence continues until the first non-hexadecimal digit is seen.  However,
+using more than two hexadecimal digits produces undefined results.  (The
+@samp{\x} escape sequence is not allowed in @sc{posix} @code{awk}.)@refill
+@end table
+
+A @dfn{constant regexp} is a regular expression description enclosed in
+slashes, such as @code{/^beginning and end$/}.  Most regexps used in
+@code{awk} programs are constant, but the @samp{~} and @samp{!~}
+operators can also match computed or ``dynamic'' regexps
+(@pxref{Regexp Usage, ,How to Use Regular Expressions}).@refill
+
+Constant regexps may be used like simple expressions.  When a
+constant regexp is not on the right hand side of the @samp{~} or
+@samp{!~} operators, it has the same meaning as if it appeared
+in a pattern, i.e. @samp{($0 ~ /foo/)}
+(@pxref{Expression Patterns, ,Expressions as Patterns}).
+This means that the two code segments,@refill
+
+@example
+if ($0 ~ /barfly/ || $0 ~ /camelot/)
+    print "found"
+@end example
+
+@noindent
+and
+
+@example
+if (/barfly/ || /camelot/)
+    print "found"
+@end example
+
+@noindent
+are exactly equivalent.  One rather bizarre consequence of this rule is
+that the following boolean expression is legal, but does not do what the user
+intended:@refill
+
+@example
+if (/foo/ ~ $1) print "found foo"
+@end example
+
+This code is ``obviously'' testing @code{$1} for a match against the regexp
+@code{/foo/}.  But in fact, the expression @code{(/foo/ ~ $1)} actually means
+@code{(($0 ~ /foo/) ~ $1)}.  In other words, first match the input record
+against the regexp @code{/foo/}.  The result will be either a 0 or a 1,
+depending upon the success or failure of the match.  Then match that result
+against the first field in the record.@refill
+
+Since it is unlikely that you would ever really wish to make this kind of
+test, @code{gawk} will issue a warning when it sees this construct in
+a program.@refill
+
+Another consequence of this rule is that the assignment statement
+
+@example
+matches = /foo/
+@end example
+
+@noindent
+will assign either 0 or 1 to the variable @code{matches}, depending
+upon the contents of the current input record.
+
+Constant regular expressions are also used as the first argument for
+the @code{sub} and @code{gsub} functions
+(@pxref{String Functions, ,Built-in Functions for String Manipulation}).@refill
+
+This feature of the language was never well documented until the
+@sc{posix} specification.
+
+You may be wondering, when is
+
+@example
+$1 ~ /foo/ @{ @dots{} @}
+@end example
+
+@noindent
+preferable to
+
+@example
+$1 ~ "foo" @{ @dots{} @}
+@end example
+
+Since the right-hand sides of both @samp{~} operators are constants,
+it is more efficient to use the @samp{/foo/} form: @code{awk} can note
+that you have supplied a regexp and store it internally in a form that
+makes pattern matching more efficient.  In the second form, @code{awk}
+must first convert the string into this internal form, and then perform
+the pattern matching.  The first form is also better style; it shows 
+clearly that you intend a regexp match.
+
+@node Variables, Arithmetic Ops, Constants, Expressions
+@section Variables
+@cindex variables, user-defined
+@cindex user-defined variables
+@c there should be more than one subsection, ideally.  Not a big deal.
+@c But usually there are supposed to be at least two.  One way to get
+@c around this is to write the info in the subsection as the info in the
+@c section itself and not have any subsections..  --mew
+
+Variables let you give names to values and refer to them later.  You have
+already seen variables in many of the examples.  The name of a variable
+must be a sequence of letters, digits and underscores, but it may not begin
+with a digit.  Case is significant in variable names; @code{a} and @code{A}
+are distinct variables.
+
+A variable name is a valid expression by itself; it represents the
+variable's current value.  Variables are given new values with
+@dfn{assignment operators} and @dfn{increment operators}.
+@xref{Assignment Ops, ,Assignment Expressions}.
+
+A few variables have special built-in meanings, such as @code{FS}, the
+field separator, and @code{NF}, the number of fields in the current
+input record.  @xref{Built-in Variables}, for a list of them.  These
+built-in variables can be used and assigned just like all other
+variables, but their values are also used or changed automatically by
+@code{awk}.  Each built-in variable's name is made entirely of upper case
+letters.
+
+Variables in @code{awk} can be assigned either numeric or string
+values.  By default, variables are initialized to the null string, which
+is effectively zero if converted to a number.  There is no need to
+``initialize'' each variable explicitly in @code{awk}, the way you would in C or most other traditional languages.
+
+@menu
+* Assignment Options::          Setting variables on the command line
+                                and a summary of command line syntax.
+                                This is an advanced method of input.
+@end menu
+
+@node Assignment Options,  , Variables, Variables
+@subsection Assigning Variables on the Command Line
+
+You can set any @code{awk} variable by including a @dfn{variable assignment}
+among the arguments on the command line when you invoke @code{awk}
+(@pxref{Command Line, ,Invoking @code{awk}}).  Such an assignment has
+this form:@refill
+
+@example
+@var{variable}=@var{text}
+@end example
+
+@noindent
+With it, you can set a variable either at the beginning of the
+@code{awk} run or in between input files.
+
+If you precede the assignment with the @samp{-v} option, like this:
+
+@example
+-v @var{variable}=@var{text}
+@end example
+
+@noindent
+then the variable is set at the very beginning, before even the
+@code{BEGIN} rules are run.  The @samp{-v} option and its assignment
+must precede all the file name arguments, as well as the program text.
+
+Otherwise, the variable assignment is performed at a time determined by
+its position among the input file arguments: after the processing of the
+preceding input file argument.  For example:
+
+@example
+awk '@{ print $n @}' n=4 inventory-shipped n=2 BBS-list
+@end example
+
+@noindent
+prints the value of field number @code{n} for all input records.  Before
+the first file is read, the command line sets the variable @code{n}
+equal to 4.  This causes the fourth field to be printed in lines from
+the file @file{inventory-shipped}.  After the first file has finished,
+but before the second file is started, @code{n} is set to 2, so that the
+second field is printed in lines from @file{BBS-list}.
+
+Command line arguments are made available for explicit examination by
+the @code{awk} program in an array named @code{ARGV}
+(@pxref{Built-in Variables}).@refill
+
+@code{awk} processes the values of command line assignments for escape
+sequences (@pxref{Constants, ,Constant Expressions}).
+
+@node Arithmetic Ops, Concatenation, Variables, Expressions
+@section Arithmetic Operators
+@cindex arithmetic operators
+@cindex operators, arithmetic
+@cindex addition
+@cindex subtraction
+@cindex multiplication
+@cindex division
+@cindex remainder
+@cindex quotient
+@cindex exponentiation
+
+The @code{awk} language uses the common arithmetic operators when
+evaluating expressions.  All of these arithmetic operators follow normal
+precedence rules, and work as you would expect them to.  This example
+divides field three by field four, adds field two, stores the result
+into field one, and prints the resulting altered input record:
+
+@example
+awk '@{ $1 = $2 + $3 / $4; print @}' inventory-shipped
+@end example
+
+The arithmetic operators in @code{awk} are:
+
+@table @code
+@item @var{x} + @var{y}
+Addition.
+
+@item @var{x} - @var{y}
+Subtraction.
+
+@item - @var{x}
+Negation.
+
+@item + @var{x}
+Unary plus.  No real effect on the expression.
+
+@item @var{x} * @var{y}
+Multiplication.
+
+@item @var{x} / @var{y}
+Division.  Since all numbers in @code{awk} are double-precision
+floating point, the result is not rounded to an integer: @code{3 / 4}
+has the value 0.75.
+
+@item @var{x} % @var{y}
+@iftex
+@cindex differences between @code{gawk} and @code{awk}
+@end iftex
+Remainder.  The quotient is rounded toward zero to an integer,
+multiplied by @var{y} and this result is subtracted from @var{x}.
+This operation is sometimes known as ``trunc-mod.''  The following
+relation always holds:
+
+@example
+b * int(a / b) + (a % b) == a
+@end example
+
+One possibly undesirable effect of this definition of remainder is that
+@code{@var{x} % @var{y}} is negative if @var{x} is negative.  Thus,
+
+@example
+-17 % 8 = -1
+@end example
+
+In other @code{awk} implementations, the signedness of the remainder
+may be machine dependent.
+
+@item @var{x} ^ @var{y}
+@itemx @var{x} ** @var{y}
+Exponentiation: @var{x} raised to the @var{y} power.  @code{2 ^ 3} has
+the value 8.  The character sequence @samp{**} is equivalent to
+@samp{^}.  (The @sc{posix} standard only specifies the use of @samp{^}
+for exponentiation.)
+@end table
+
+@node Concatenation, Comparison Ops, Arithmetic Ops, Expressions
+@section String Concatenation
+
+@cindex string operators
+@cindex operators, string
+@cindex concatenation
+There is only one string operation: concatenation.  It does not have a
+specific operator to represent it.  Instead, concatenation is performed by
+writing expressions next to one another, with no operator.  For example:
+
+@example
+awk '@{ print "Field number one: " $1 @}' BBS-list
+@end example
+
+@noindent
+produces, for the first record in @file{BBS-list}:
+
+@example
+Field number one: aardvark
+@end example
+
+Without the space in the string constant after the @samp{:}, the line
+would run together.  For example:
+
+@example
+awk '@{ print "Field number one:" $1 @}' BBS-list
+@end example
+
+@noindent
+produces, for the first record in @file{BBS-list}:
+
+@example
+Field number one:aardvark
+@end example
+
+Since string concatenation does not have an explicit operator, it is
+often necessary to insure that it happens where you want it to by
+enclosing the items to be concatenated in parentheses.  For example, the
+following code fragment does not concatenate @code{file} and @code{name}
+as you might expect:
+
+@example
+file = "file"
+name = "name"
+print "something meaningful" > file name
+@end example
+
+@noindent
+It is necessary to use the following:
+
+@example
+print "something meaningful" > (file name)
+@end example
+
+We recommend you use parentheses around concatenation in all but the
+most common contexts (such as in the right-hand operand of @samp{=}).
+
+@ignore
+@code{gawk} actually now allows a concatenation on the right hand
+side of a @code{>} redirection, but other @code{awk}s don't.  So for
+now we won't mention that fact.
+@end ignore
+
+@node Comparison Ops, Boolean Ops, Concatenation, Expressions
+@section Comparison Expressions
+@cindex comparison expressions
+@cindex expressions, comparison
+@cindex relational operators
+@cindex operators, relational
+@cindex regexp operators
+
+@dfn{Comparison expressions} compare strings or numbers for
+relationships such as equality.  They are written using @dfn{relational
+operators}, which are a superset of those in C.  Here is a table of
+them:
+
+@table @code
+@item @var{x} < @var{y}
+True if @var{x} is less than @var{y}.
+
+@item @var{x} <= @var{y}
+True if @var{x} is less than or equal to @var{y}.
+
+@item @var{x} > @var{y}
+True if @var{x} is greater than @var{y}.
+
+@item @var{x} >= @var{y}
+True if @var{x} is greater than or equal to @var{y}.
+
+@item @var{x} == @var{y}
+True if @var{x} is equal to @var{y}.
+
+@item @var{x} != @var{y}
+True if @var{x} is not equal to @var{y}.
+
+@item @var{x} ~ @var{y}
+True if the string @var{x} matches the regexp denoted by @var{y}.
+
+@item @var{x} !~ @var{y}
+True if the string @var{x} does not match the regexp denoted by @var{y}.
+
+@item @var{subscript} in @var{array}
+True if array @var{array} has an element with the subscript @var{subscript}.
+@end table
+
+Comparison expressions have the value 1 if true and 0 if false.
+
+The rules @code{gawk} uses for performing comparisons are based on those
+in draft 11.2 of the @sc{posix} standard.  The @sc{posix} standard introduced
+the concept of a @dfn{numeric string}, which is simply a string that looks
+like a number, for example, @code{@w{" +2"}}.
+
+@vindex CONVFMT
+When performing a relational operation, @code{gawk} considers the type of an
+operand to be the type it received on its last @emph{assignment}, rather
+than the type of its last @emph{use}
+(@pxref{Values, ,Numeric and String Values}).
+This type is @emph{unknown} when the operand is from an ``external'' source:
+field variables, command line arguments, array elements resulting from a
+@code{split} operation, and the value of an @code{ENVIRON} element.
+In this case only, if the operand is a numeric string, then it is
+considered to be of both string type and numeric type.  If at least one
+operand of a comparison is of string type only, then a string
+comparison is performed.  Any numeric operand will be converted to a
+string using the value of @code{CONVFMT}
+(@pxref{Conversion, ,Conversion of Strings and Numbers}).
+If one operand of a comparison is numeric, and the other operand is
+either numeric or both numeric and string, then @code{gawk} does a
+numeric comparison.  If both operands have both types, then the
+comparison is numeric.  Strings are compared
+by comparing the first character of each, then the second character of each,
+and so on.  Thus @code{"10"} is less than @code{"9"}.  If there are two
+strings where one is a prefix of the other, the shorter string is less than
+the longer one.  Thus @code{"abc"} is less than @code{"abcd"}.@refill
+
+Here are some sample expressions, how @code{gawk} compares them, and what
+the result of the comparison is.
+
+@table @code
+@item 1.5 <= 2.0
+numeric comparison (true)
+
+@item "abc" >= "xyz"
+string comparison (false)
+
+@item 1.5 != " +2"
+string comparison (true)
+
+@item "1e2" < "3"
+string comparison (true)
+
+@item a = 2; b = "2"
+@itemx a == b
+string comparison (true)
+@end table
+
+@example
+echo 1e2 3 | awk '@{ print ($1 < $2) ? "true" : "false" @}'
+@end example
+
+@noindent
+prints @samp{false} since both @code{$1} and @code{$2} are numeric
+strings and thus have both string and numeric types, thus dictating
+a numeric comparison.
+
+The purpose of the comparison rules and the use of numeric strings is
+to attempt to produce the behavior that is ``least surprising,'' while
+still ``doing the right thing.''
+
+String comparisons and regular expression comparisons are very different.
+For example,
+
+@example
+$1 == "foo"
+@end example
+
+@noindent
+has the value of 1, or is true, if the first field of the current input
+record is precisely @samp{foo}.  By contrast, 
+
+@example
+$1 ~ /foo/
+@end example
+
+@noindent
+has the value 1 if the first field contains @samp{foo}, such as @samp{foobar}.
+
+The right hand operand of the @samp{~} and @samp{!~} operators may be
+either a constant regexp (@code{/@dots{}/}), or it may be an ordinary
+expression, in which case the value of the expression as a string is a
+dynamic regexp (@pxref{Regexp Usage, ,How to Use Regular Expressions}).
+
+@cindex regexp as expression
+In very recent implementations of @code{awk}, a constant regular
+expression in slashes by itself is also an expression.  The regexp
+@code{/@var{regexp}/} is an abbreviation for this comparison expression:
+
+@example
+$0 ~ /@var{regexp}/
+@end example
+
+In some contexts it may be necessary to write parentheses around the
+regexp to avoid confusing the @code{gawk} parser.  For example,
+@code{(/x/ - /y/) > threshold} is not allowed, but @code{((/x/) - (/y/))
+> threshold} parses properly.
+
+One special place where @code{/foo/} is @emph{not} an abbreviation for
+@code{$0 ~ /foo/} is when it is the right-hand operand of @samp{~} or
+@samp{!~}! @xref{Constants, ,Constant Expressions}, where this is
+discussed in more detail.
+
+@node Boolean Ops, Assignment Ops, Comparison Ops, Expressions
+@section Boolean Expressions
+@cindex expressions, boolean
+@cindex boolean expressions
+@cindex operators, boolean
+@cindex boolean operators
+@cindex logical operations
+@cindex and operator
+@cindex or operator
+@cindex not operator
+
+A @dfn{boolean expression} is a combination of comparison expressions or
+matching expressions, using the boolean operators ``or''
+(@samp{||}), ``and'' (@samp{&&}), and ``not'' (@samp{!}), along with
+parentheses to control nesting.  The truth of the boolean expression is
+computed by combining the truth values of the component expressions.
+
+Boolean expressions can be used wherever comparison and matching
+expressions can be used.  They can be used in @code{if}, @code{while}
+@code{do} and @code{for} statements.  They have numeric values (1 if true,
+0 if false), which come into play if the result of the boolean expression
+is stored in a variable, or used in arithmetic.@refill
+
+In addition, every boolean expression is also a valid boolean pattern, so
+you can use it as a pattern to control the execution of rules.
+
+Here are descriptions of the three boolean operators, with an example of
+each.  It may be instructive to compare these examples with the
+analogous examples of boolean patterns
+(@pxref{Boolean Patterns, ,Boolean Operators and Patterns}), which
+use the same boolean operators in patterns instead of expressions.@refill
+
+@table @code
+@item @var{boolean1} && @var{boolean2}
+True if both @var{boolean1} and @var{boolean2} are true.  For example,
+the following statement prints the current input record if it contains
+both @samp{2400} and @samp{foo}.@refill
+
+@smallexample
+if ($0 ~ /2400/ && $0 ~ /foo/) print
+@end smallexample
+
+The subexpression @var{boolean2} is evaluated only if @var{boolean1}
+is true.  This can make a difference when @var{boolean2} contains
+expressions that have side effects: in the case of @code{$0 ~ /foo/ &&
+($2 == bar++)}, the variable @code{bar} is not incremented if there is
+no @samp{foo} in the record.
+
+@item @var{boolean1} || @var{boolean2}
+True if at least one of @var{boolean1} or @var{boolean2} is true.
+For example, the following command prints all records in the input
+file @file{BBS-list} that contain @emph{either} @samp{2400} or
+@samp{foo}, or both.@refill
+
+@smallexample
+awk '@{ if ($0 ~ /2400/ || $0 ~ /foo/) print @}' BBS-list
+@end smallexample
+
+The subexpression @var{boolean2} is evaluated only if @var{boolean1}
+is false.  This can make a difference when @var{boolean2} contains
+expressions that have side effects.
+
+@item !@var{boolean}
+True if @var{boolean} is false.  For example, the following program prints
+all records in the input file @file{BBS-list} that do @emph{not} contain the
+string @samp{foo}.
+
+@smallexample
+awk '@{ if (! ($0 ~ /foo/)) print @}' BBS-list
+@end smallexample
+@end table
+
+@node Assignment Ops, Increment Ops, Boolean Ops, Expressions
+@section Assignment Expressions
+@cindex assignment operators
+@cindex operators, assignment
+@cindex expressions, assignment
+
+An @dfn{assignment} is an expression that stores a new value into a
+variable.  For example, let's assign the value 1 to the variable
+@code{z}:@refill
+
+@example
+z = 1
+@end example
+
+After this expression is executed, the variable @code{z} has the value 1.
+Whatever old value @code{z} had before the assignment is forgotten.
+
+Assignments can store string values also.  For example, this would store
+the value @code{"this food is good"} in the variable @code{message}:
+
+@example
+thing = "food"
+predicate = "good"
+message = "this " thing " is " predicate
+@end example
+
+@noindent
+(This also illustrates concatenation of strings.)
+
+The @samp{=} sign is called an @dfn{assignment operator}.  It is the
+simplest assignment operator because the value of the right-hand
+operand is stored unchanged.
+
+@cindex side effect
+Most operators (addition, concatenation, and so on) have no effect
+except to compute a value.  If you ignore the value, you might as well
+not use the operator.  An assignment operator is different; it does
+produce a value, but even if you ignore the value, the assignment still
+makes itself felt through the alteration of the variable.  We call this
+a @dfn{side effect}.
+
+@cindex lvalue
+The left-hand operand of an assignment need not be a variable
+(@pxref{Variables}); it can also be a field
+(@pxref{Changing Fields, ,Changing the Contents of a Field}) or
+an array element (@pxref{Arrays, ,Arrays in @code{awk}}).
+These are all called @dfn{lvalues},
+which means they can appear on the left-hand side of an assignment operator.
+The right-hand operand may be any expression; it produces the new value
+which the assignment stores in the specified variable, field or array
+element.@refill
+
+It is important to note that variables do @emph{not} have permanent types.
+The type of a variable is simply the type of whatever value it happens
+to hold at the moment.  In the following program fragment, the variable
+@code{foo} has a numeric value at first, and a string value later on:
+
+@example
+foo = 1
+print foo
+foo = "bar"
+print foo
+@end example
+
+@noindent
+When the second assignment gives @code{foo} a string value, the fact that
+it previously had a numeric value is forgotten.
+
+An assignment is an expression, so it has a value: the same value that
+is assigned.  Thus, @code{z = 1} as an expression has the value 1.
+One consequence of this is that you can write multiple assignments together:
+
+@example
+x = y = z = 0
+@end example
+
+@noindent
+stores the value 0 in all three variables.  It does this because the
+value of @code{z = 0}, which is 0, is stored into @code{y}, and then
+the value of @code{y = z = 0}, which is 0, is stored into @code{x}.
+
+You can use an assignment anywhere an expression is called for.  For
+example, it is valid to write @code{x != (y = 1)} to set @code{y} to 1
+and then test whether @code{x} equals 1.  But this style tends to make
+programs hard to read; except in a one-shot program, you should
+rewrite it to get rid of such nesting of assignments.  This is never very
+hard.
+
+Aside from @samp{=}, there are several other assignment operators that
+do arithmetic with the old value of the variable.  For example, the
+operator @samp{+=} computes a new value by adding the right-hand value
+to the old value of the variable.  Thus, the following assignment adds
+5 to the value of @code{foo}:
+
+@example
+foo += 5
+@end example
+
+@noindent
+This is precisely equivalent to the following:
+
+@example
+foo = foo + 5
+@end example
+
+@noindent
+Use whichever one makes the meaning of your program clearer.
+
+Here is a table of the arithmetic assignment operators.  In each
+case, the right-hand operand is an expression whose value is converted
+to a number.
+
+@table @code
+@item @var{lvalue} += @var{increment}
+Adds @var{increment} to the value of @var{lvalue} to make the new value
+of @var{lvalue}.
+
+@item @var{lvalue} -= @var{decrement}
+Subtracts @var{decrement} from the value of @var{lvalue}.
+
+@item @var{lvalue} *= @var{coefficient}
+Multiplies the value of @var{lvalue} by @var{coefficient}.
+
+@item @var{lvalue} /= @var{quotient}
+Divides the value of @var{lvalue} by @var{quotient}.
+
+@item @var{lvalue} %= @var{modulus}
+Sets @var{lvalue} to its remainder by @var{modulus}.
+
+@item @var{lvalue} ^= @var{power}
+@itemx @var{lvalue} **= @var{power}
+Raises @var{lvalue} to the power @var{power}.
+(Only the @code{^=} operator is specified by @sc{posix}.)
+@end table
+
+@ignore
+From: gatech!ames!elroy!cit-vax!EQL.Caltech.Edu!rankin (Pat Rankin)
+     In the discussion of assignment operators, it states that
+``foo += 5'' "is precisely equivalent to" ``foo = foo + 5'' (p.77).  That
+may be true for simple variables, but it's not true for expressions with
+side effects, like array references.  For proof, try
+  BEGIN {
+	  foo[rand()] += 5;               for (x in foo) print x, foo[x]
+	  bar[rand()] = bar[rand()] + 5;  for (x in bar) print x, bar[x]
+  }
+I suspect that the original statement is simply untrue--that '+=' is more
+efficient in all cases.
+
+ADR --- Try to add something about this here for the next go 'round.
+@end ignore
+
+@node Increment Ops, Conversion, Assignment Ops, Expressions
+@section Increment Operators
+
+@cindex increment operators
+@cindex operators, increment
+@dfn{Increment operators} increase or decrease the value of a variable
+by 1.  You could do the same thing with an assignment operator, so
+the increment operators add no power to the @code{awk} language; but they
+are convenient abbreviations for something very common.
+
+The operator to add 1 is written @samp{++}.  It can be used to increment
+a variable either before or after taking its value.
+
+To pre-increment a variable @var{v}, write @code{++@var{v}}.  This adds
+1 to the value of @var{v} and that new value is also the value of this
+expression.  The assignment expression @code{@var{v} += 1} is completely
+equivalent.
+
+Writing the @samp{++} after the variable specifies post-increment.  This
+increments the variable value just the same; the difference is that the
+value of the increment expression itself is the variable's @emph{old}
+value.  Thus, if @code{foo} has the value 4, then the expression @code{foo++}
+has the value 4, but it changes the value of @code{foo} to 5.
+
+The post-increment @code{foo++} is nearly equivalent to writing @code{(foo
++= 1) - 1}.  It is not perfectly equivalent because all numbers in
+@code{awk} are floating point: in floating point, @code{foo + 1 - 1} does
+not necessarily equal @code{foo}.  But the difference is minute as
+long as you stick to numbers that are fairly small (less than a trillion).
+
+Any lvalue can be incremented.  Fields and array elements are incremented
+just like variables.  (Use @samp{$(i++)} when you wish to do a field reference
+and a variable increment at the same time.  The parentheses are necessary
+because of the precedence of the field reference operator, @samp{$}.)
+@c expert information in the last parenthetical remark
+
+The decrement operator @samp{--} works just like @samp{++} except that
+it subtracts 1 instead of adding.  Like @samp{++}, it can be used before
+the lvalue to pre-decrement or after it to post-decrement.
+
+Here is a summary of increment and decrement expressions.
+
+@table @code
+@item ++@var{lvalue}
+This expression increments @var{lvalue} and the new value becomes the
+value of this expression.
+
+@item @var{lvalue}++
+This expression causes the contents of @var{lvalue} to be incremented.
+The value of the expression is the @emph{old} value of @var{lvalue}.
+
+@item --@var{lvalue}
+Like @code{++@var{lvalue}}, but instead of adding, it subtracts.  It
+decrements @var{lvalue} and delivers the value that results.
+
+@item @var{lvalue}--
+Like @code{@var{lvalue}++}, but instead of adding, it subtracts.  It
+decrements @var{lvalue}.  The value of the expression is the @emph{old}
+value of @var{lvalue}.
+@end table
+
+@node Conversion, Values, Increment Ops, Expressions
+@section Conversion of Strings and Numbers
+
+@cindex conversion of strings and numbers
+Strings are converted to numbers, and numbers to strings, if the context
+of the @code{awk} program demands it.  For example, if the value of
+either @code{foo} or @code{bar} in the expression @code{foo + bar}
+happens to be a string, it is converted to a number before the addition
+is performed.  If numeric values appear in string concatenation, they
+are converted to strings.  Consider this:@refill
+
+@example
+two = 2; three = 3
+print (two three) + 4
+@end example
+
+@noindent
+This eventually prints the (numeric) value 27.  The numeric values of
+the variables @code{two} and @code{three} are converted to strings and
+concatenated together, and the resulting string is converted back to the
+number 23, to which 4 is then added.
+
+If, for some reason, you need to force a number to be converted to a
+string, concatenate the null string with that number.  To force a string
+to be converted to a number, add zero to that string.
+
+A string is converted to a number by interpreting a numeric prefix
+of the string as numerals:
+@code{"2.5"} converts to 2.5, @code{"1e3"} converts to 1000, and @code{"25fix"}
+has a numeric value of 25.
+Strings that can't be interpreted as valid numbers are converted to
+zero.
+
+@vindex CONVFMT
+The exact manner in which numbers are converted into strings is controlled
+by the @code{awk} built-in variable @code{CONVFMT} (@pxref{Built-in Variables}).
+Numbers are converted using a special version of the @code{sprintf} function
+(@pxref{Built-in, ,Built-in Functions}) with @code{CONVFMT} as the format
+specifier.@refill
+
+@code{CONVFMT}'s default value is @code{"%.6g"}, which prints a value with
+at least six significant digits.  For some applications you will want to
+change it to specify more precision.  Double precision on most modern
+machines gives you 16 or 17 decimal digits of precision.
+
+Strange results can happen if you set @code{CONVFMT} to a string that doesn't
+tell @code{sprintf} how to format floating point numbers in a useful way.
+For example, if you forget the @samp{%} in the format, all numbers will be
+converted to the same constant string.@refill
+
+As a special case, if a number is an integer, then the result of converting
+it to a string is @emph{always} an integer, no matter what the value of
+@code{CONVFMT} may be.  Given the following code fragment:
+
+@example
+CONVFMT = "%2.2f"
+a = 12
+b = a ""
+@end example
+
+@noindent
+@code{b} has the value @code{"12"}, not @code{"12.00"}.
+
+@ignore
+For the 2.14 version, describe the ``stickyness'' of conversions.  Right now
+the manual assumes everywhere that variables are either numbers or strings;
+in fact both kinds of values may be valid.  If both happen to be valid, a
+conversion isn't necessary and isn't done.  Revising the manual to be
+consistent with this, though, is too big a job to tackle at the moment.
+
+7/92: This has sort of been done, only the section isn't completely right!
+      What to do?
+7/92: Pretty much fixed, at least for the short term, thanks to text
+      from David.
+@end ignore
+
+@vindex OFMT
+Prior to the @sc{posix} standard, @code{awk} specified that the value
+of @code{OFMT} was used for converting numbers to strings.  @code{OFMT}
+specifies the output format to use when printing numbers with @code{print}.
+@code{CONVFMT} was introduced in order to separate the semantics of
+conversions from the semantics of printing.  Both @code{CONVFMT} and
+@code{OFMT} have the same default value: @code{"%.6g"}.  In the vast majority
+of cases, old @code{awk} programs will not change their behavior.
+However, this use of @code{OFMT} is something to keep in mind if you must
+port your program to other implementations of @code{awk}; we recommend
+that instead of changing your programs, you just port @code{gawk} itself!@refill
+
+@node Values, Conditional Exp, Conversion, Expressions
+@section Numeric and String Values
+@cindex conversion of strings and numbers
+
+Through most of this manual, we present @code{awk} values (such as constants,
+fields, or variables) as @emph{either} numbers @emph{or} strings.  This is
+a convenient way to think about them, since typically they are used in only
+one way, or the other.
+
+In truth though, @code{awk} values can be @emph{both} string and
+numeric, at the same time.  Internally, @code{awk} represents values
+with a string, a (floating point) number, and an indication that one,
+the other, or both representations of the value are valid.
+
+Keeping track of both kinds of values is important for execution
+efficiency:  a variable can acquire a string value the first time it
+is used as a string, and then that string value can be used until the
+variable is assigned a new value.  Thus, if a variable with only a numeric
+value is used in several concatenations in a row, it only has to be given
+a string representation once.  The numeric value remains valid, so that
+no conversion back to a number is necessary if the variable is later used
+in an arithmetic expression.
+
+Tracking both kinds of values is also important for precise numerical
+calculations.  Consider the following:
+
+@smallexample
+a = 123.321
+CONVFMT = "%3.1f"
+b = a " is a number"
+c = a + 1.654
+@end smallexample
+
+@noindent
+The variable @code{a} receives a string value in the concatenation and
+assignment to @code{b}.  The string value of @code{a} is @code{"123.3"}.
+If the numeric value was lost when it was converted to a string, then the
+numeric use of @code{a} in the last statement would lose information.
+@code{c} would be assigned the value 124.954 instead of 124.975.
+Such errors accumulate rapidly, and very adversely affect numeric
+computations.@refill
+
+Once a numeric value acquires a corresponding string value, it stays valid
+until a new assignment is made.  If @code{CONVFMT}
+(@pxref{Conversion, ,Conversion of Strings and Numbers}) changes in the
+meantime, the old string value will still be used.  For example:@refill
+
+@smallexample
+BEGIN @{
+    CONVFMT = "%2.2f"
+    a = 123.456
+    b = a ""                # force `a' to have string value too
+    printf "a = %s\n", a
+    CONVFMT = "%.6g"
+    printf "a = %s\n", a
+    a += 0                  # make `a' numeric only again
+    printf "a = %s\n", a    # use `a' as string
+@}
+@end smallexample
+
+@noindent
+This program prints @samp{a = 123.46} twice, and then prints
+@samp{a = 123.456}.
+
+@xref{Conversion, ,Conversion of Strings and Numbers}, for the rules that
+specify how string values are made from numeric values.
+
+@node Conditional Exp, Function Calls, Values, Expressions
+@section Conditional Expressions
+@cindex conditional expression
+@cindex expression, conditional
+
+A @dfn{conditional expression} is a special kind of expression with
+three operands.  It allows you to use one expression's value to select
+one of two other expressions.
+
+The conditional expression looks the same as in the C language:
+
+@example
+@var{selector} ? @var{if-true-exp} : @var{if-false-exp}
+@end example
+
+@noindent
+There are three subexpressions.  The first, @var{selector}, is always
+computed first.  If it is ``true'' (not zero and not null) then
+@var{if-true-exp} is computed next and its value becomes the value of
+the whole expression.  Otherwise, @var{if-false-exp} is computed next
+and its value becomes the value of the whole expression.@refill
+
+For example, this expression produces the absolute value of @code{x}:
+
+@example
+x > 0 ? x : -x
+@end example
+
+Each time the conditional expression is computed, exactly one of
+@var{if-true-exp} and @var{if-false-exp} is computed; the other is ignored.
+This is important when the expressions contain side effects.  For example,
+this conditional expression examines element @code{i} of either array
+@code{a} or array @code{b}, and increments @code{i}.
+
+@example
+x == y ? a[i++] : b[i++]
+@end example
+
+@noindent
+This is guaranteed to increment @code{i} exactly once, because each time
+one or the other of the two increment expressions is executed,
+and the other is not.
+
+@node Function Calls, Precedence, Conditional Exp, Expressions
+@section Function Calls
+@cindex function call
+@cindex calling a function
+
+A @dfn{function} is a name for a particular calculation.  Because it has
+a name, you can ask for it by name at any point in the program.  For
+example, the function @code{sqrt} computes the square root of a number.
+
+A fixed set of functions are @dfn{built-in}, which means they are
+available in every @code{awk} program.  The @code{sqrt} function is one
+of these.  @xref{Built-in, ,Built-in Functions}, for a list of built-in
+functions and their descriptions.  In addition, you can define your own
+functions in the program for use elsewhere in the same program.
+@xref{User-defined, ,User-defined Functions}, for how to do this.@refill
+
+@cindex arguments in function call
+The way to use a function is with a @dfn{function call} expression,
+which consists of the function name followed by a list of
+@dfn{arguments} in parentheses.  The arguments are expressions which
+give the raw materials for the calculation that the function will do.
+When there is more than one argument, they are separated by commas.  If
+there are no arguments, write just @samp{()} after the function name.
+Here are some examples:
+
+@example
+sqrt(x^2 + y^2)      # @r{One argument}
+atan2(y, x)          # @r{Two arguments}
+rand()               # @r{No arguments}
+@end example
+
+@strong{Do not put any space between the function name and the
+open-parenthesis!}  A user-defined function name looks just like the name of
+a variable, and space would make the expression look like concatenation
+of a variable with an expression inside parentheses.  Space before the
+parenthesis is harmless with built-in functions, but it is best not to get
+into the habit of using space to avoid mistakes with user-defined
+functions. 
+
+Each function expects a particular number of arguments.  For example, the
+@code{sqrt} function must be called with a single argument, the number
+to take the square root of:
+
+@example
+sqrt(@var{argument})
+@end example
+
+Some of the built-in functions allow you to omit the final argument.
+If you do so, they use a reasonable default.
+@xref{Built-in, ,Built-in Functions}, for full details.  If arguments
+are omitted in calls to user-defined functions, then those arguments are
+treated as local variables, initialized to the null string
+(@pxref{User-defined, ,User-defined Functions}).@refill
+
+Like every other expression, the function call has a value, which is
+computed by the function based on the arguments you give it.  In this
+example, the value of @code{sqrt(@var{argument})} is the square root of the
+argument.  A function can also have side effects, such as assigning the
+values of certain variables or doing I/O.
+
+Here is a command to read numbers, one number per line, and print the
+square root of each one:
+
+@example
+awk '@{ print "The square root of", $1, "is", sqrt($1) @}'
+@end example
+
+@node Precedence,  , Function Calls, Expressions
+@section Operator Precedence (How Operators Nest)
+@cindex precedence
+@cindex operator precedence
+
+@dfn{Operator precedence} determines how operators are grouped, when
+different operators appear close by in one expression.  For example,
+@samp{*} has higher precedence than @samp{+}; thus, @code{a + b * c}
+means to multiply @code{b} and @code{c}, and then add @code{a} to the
+product (i.e., @code{a + (b * c)}).
+
+You can overrule the precedence of the operators by using parentheses.
+You can think of the precedence rules as saying where the
+parentheses are assumed if you do not write parentheses yourself.  In
+fact, it is wise to always use parentheses whenever you have an unusual
+combination of operators, because other people who read the program may
+not remember what the precedence is in this case.  You might forget,
+too; then you could make a mistake.  Explicit parentheses will help prevent
+any such mistake.
+
+When operators of equal precedence are used together, the leftmost
+operator groups first, except for the assignment, conditional and
+exponentiation operators, which group in the opposite order.
+Thus, @code{a - b + c} groups as @code{(a - b) + c};
+@code{a = b = c} groups as @code{a = (b = c)}.@refill
+
+The precedence of prefix unary operators does not matter as long as only
+unary operators are involved, because there is only one way to parse
+them---innermost first.  Thus, @code{$++i} means @code{$(++i)} and
+@code{++$x} means @code{++($x)}.  However, when another operator follows
+the operand, then the precedence of the unary operators can matter.
+Thus, @code{$x^2} means @code{($x)^2}, but @code{-x^2} means
+@code{-(x^2)}, because @samp{-} has lower precedence than @samp{^}
+while @samp{$} has higher precedence.
+
+Here is a table of the operators of @code{awk}, in order of increasing
+precedence:
+
+@table @asis
+@item assignment
+@samp{=}, @samp{+=}, @samp{-=}, @samp{*=}, @samp{/=}, @samp{%=},
+@samp{^=}, @samp{**=}.  These operators group right-to-left.
+(The @samp{**=} operator is not specified by @sc{posix}.)
+
+@item conditional
+@samp{?:}.  This operator groups right-to-left.
+
+@item logical ``or''.
+@samp{||}.
+
+@item logical ``and''.
+@samp{&&}.
+
+@item array membership
+@samp{in}.
+
+@item matching
+@samp{~}, @samp{!~}.
+
+@item relational, and redirection
+The relational operators and the redirections have the same precedence
+level.  Characters such as @samp{>} serve both as relationals and as
+redirections; the context distinguishes between the two meanings.
+
+The relational operators are @samp{<}, @samp{<=}, @samp{==}, @samp{!=},
+@samp{>=} and @samp{>}.
+
+The I/O redirection operators are @samp{<}, @samp{>}, @samp{>>} and
+@samp{|}.
+
+Note that I/O redirection operators in @code{print} and @code{printf}
+statements belong to the statement level, not to expressions.  The
+redirection does not produce an expression which could be the operand of
+another operator.  As a result, it does not make sense to use a
+redirection operator near another operator of lower precedence, without
+parentheses.  Such combinations, for example @samp{print foo > a ? b :
+c}, result in syntax errors.
+
+@item concatenation
+No special token is used to indicate concatenation.
+The operands are simply written side by side.
+
+@item add, subtract
+@samp{+}, @samp{-}.
+
+@item multiply, divide, mod
+@samp{*}, @samp{/}, @samp{%}.
+
+@item unary plus, minus, ``not''
+@samp{+}, @samp{-}, @samp{!}.
+
+@item exponentiation
+@samp{^}, @samp{**}.  These operators group right-to-left.
+(The @samp{**} operator is not specified by @sc{posix}.)
+
+@item increment, decrement
+@samp{++}, @samp{--}.
+
+@item field
+@samp{$}.
+@end table
+
+@node Statements, Arrays, Expressions, Top
+@chapter Control Statements in Actions
+@cindex control statement
+
+@dfn{Control statements} such as @code{if}, @code{while}, and so on
+control the flow of execution in @code{awk} programs.  Most of the
+control statements in @code{awk} are patterned on similar statements in
+C.
+
+All the control statements start with special keywords such as @code{if}
+and @code{while}, to distinguish them from simple expressions.
+
+Many control statements contain other statements; for example, the
+@code{if} statement contains another statement which may or may not be
+executed.  The contained statement is called the @dfn{body}.  If you
+want to include more than one statement in the body, group them into a
+single compound statement with curly braces, separating them with
+newlines or semicolons.
+
+@menu
+* If Statement::                Conditionally execute 
+                                some @code{awk} statements.
+* While Statement::             Loop until some condition is satisfied.
+* Do Statement::                Do specified action while looping until some
+                                condition is satisfied.
+* For Statement::               Another looping statement, that provides
+                                initialization and increment clauses.
+* Break Statement::             Immediately exit the innermost enclosing loop.
+* Continue Statement::          Skip to the end of the innermost 
+                                enclosing loop.
+* Next Statement::              Stop processing the current input record.
+* Next File Statement::         Stop processing the current file.
+* Exit Statement::              Stop execution of @code{awk}.
+@end menu
+
+@node If Statement, While Statement, Statements, Statements
+@section The @code{if} Statement
+
+@cindex @code{if} statement
+The @code{if}-@code{else} statement is @code{awk}'s decision-making
+statement.  It looks like this:@refill
+
+@example
+if (@var{condition}) @var{then-body} @r{[}else @var{else-body}@r{]}
+@end example
+
+@noindent
+@var{condition} is an expression that controls what the rest of the
+statement will do.  If @var{condition} is true, @var{then-body} is
+executed; otherwise, @var{else-body} is executed (assuming that the
+@code{else} clause is present).  The @code{else} part of the statement is
+optional.  The condition is considered false if its value is zero or
+the null string, and true otherwise.@refill
+
+Here is an example:
+
+@example
+if (x % 2 == 0)
+    print "x is even"
+else
+    print "x is odd"
+@end example
+
+In this example, if the expression @code{x % 2 == 0} is true (that is,
+the value of @code{x} is divisible by 2), then the first @code{print}
+statement is executed, otherwise the second @code{print} statement is
+performed.@refill
+
+If the @code{else} appears on the same line as @var{then-body}, and
+@var{then-body} is not a compound statement (i.e., not surrounded by
+curly braces), then a semicolon must separate @var{then-body} from
+@code{else}.  To illustrate this, let's rewrite the previous example:
+
+@example
+awk '@{ if (x % 2 == 0) print "x is even"; else
+        print "x is odd" @}'
+@end example
+
+@noindent
+If you forget the @samp{;}, @code{awk} won't be able to parse the
+statement, and you will get a syntax error.
+
+We would not actually write this example this way, because a human
+reader might fail to see the @code{else} if it were not the first thing
+on its line.
+
+@node While Statement, Do Statement, If Statement, Statements
+@section The @code{while} Statement
+@cindex @code{while} statement
+@cindex loop
+@cindex body of a loop
+
+In programming, a @dfn{loop} means a part of a program that is (or at least can
+be) executed two or more times in succession.
+
+The @code{while} statement is the simplest looping statement in
+@code{awk}.  It repeatedly executes a statement as long as a condition is
+true.  It looks like this:
+
+@example
+while (@var{condition})
+  @var{body}
+@end example
+
+@noindent
+Here @var{body} is a statement that we call the @dfn{body} of the loop,
+and @var{condition} is an expression that controls how long the loop
+keeps running.
+
+The first thing the @code{while} statement does is test @var{condition}.
+If @var{condition} is true, it executes the statement @var{body}.
+(@var{condition} is true when the value 
+is not zero and not a null string.)  After @var{body} has been executed,
+@var{condition} is tested again, and if it is still true, @var{body} is
+executed again.  This process repeats until @var{condition} is no longer
+true.  If @var{condition} is initially false, the body of the loop is
+never executed.@refill
+
+This example prints the first three fields of each record, one per line.
+
+@example
+awk '@{ i = 1
+       while (i <= 3) @{
+           print $i
+           i++
+       @}
+@}'
+@end example
+
+@noindent
+Here the body of the loop is a compound statement enclosed in braces,
+containing two statements.
+
+The loop works like this: first, the value of @code{i} is set to 1.
+Then, the @code{while} tests whether @code{i} is less than or equal to
+three.  This is the case when @code{i} equals one, so the @code{i}-th
+field is printed.  Then the @code{i++} increments the value of @code{i}
+and the loop repeats.  The loop terminates when @code{i} reaches 4.
+
+As you can see, a newline is not required between the condition and the
+body; but using one makes the program clearer unless the body is a
+compound statement or is very simple.  The newline after the open-brace
+that begins the compound statement is not required either, but the
+program would be hard to read without it.
+
+@node Do Statement, For Statement, While Statement, Statements
+@section The @code{do}-@code{while} Statement
+
+The @code{do} loop is a variation of the @code{while} looping statement.
+The @code{do} loop executes the @var{body} once, then repeats @var{body}
+as long as @var{condition} is true.  It looks like this:
+
+@example
+do
+  @var{body}
+while (@var{condition})
+@end example
+
+Even if @var{condition} is false at the start, @var{body} is executed at
+least once (and only once, unless executing @var{body} makes
+@var{condition} true).  Contrast this with the corresponding
+@code{while} statement:
+
+@example
+while (@var{condition})
+  @var{body}
+@end example
+
+@noindent
+This statement does not execute @var{body} even once if @var{condition}
+is false to begin with.
+
+Here is an example of a @code{do} statement:
+
+@example
+awk '@{ i = 1
+       do @{
+          print $0
+          i++
+       @} while (i <= 10)
+@}'
+@end example
+
+@noindent
+prints each input record ten times.  It isn't a very realistic example,
+since in this case an ordinary @code{while} would do just as well.  But
+this reflects actual experience; there is only occasionally a real use
+for a @code{do} statement.@refill
+
+@node For Statement, Break Statement, Do Statement, Statements
+@section The @code{for} Statement
+@cindex @code{for} statement
+
+The @code{for} statement makes it more convenient to count iterations of a
+loop.  The general form of the @code{for} statement looks like this:@refill
+
+@example
+for (@var{initialization}; @var{condition}; @var{increment})
+  @var{body}
+@end example
+
+@noindent
+This statement starts by executing @var{initialization}.  Then, as long
+as @var{condition} is true, it repeatedly executes @var{body} and then
+@var{increment}.  Typically @var{initialization} sets a variable to
+either zero or one, @var{increment} adds 1 to it, and @var{condition}
+compares it against the desired number of iterations.
+
+Here is an example of a @code{for} statement:
+
+@example
+@group
+awk '@{ for (i = 1; i <= 3; i++)
+          print $i
+@}'
+@end group
+@end example
+
+@noindent
+This prints the first three fields of each input record, one field per
+line.
+
+In the @code{for} statement, @var{body} stands for any statement, but
+@var{initialization}, @var{condition} and @var{increment} are just
+expressions.  You cannot set more than one variable in the
+@var{initialization} part unless you use a multiple assignment statement
+such as @code{x = y = 0}, which is possible only if all the initial values
+are equal.  (But you can initialize additional variables by writing
+their assignments as separate statements preceding the @code{for} loop.)
+
+The same is true of the @var{increment} part; to increment additional
+variables, you must write separate statements at the end of the loop.
+The C compound expression, using C's comma operator, would be useful in
+this context, but it is not supported in @code{awk}.
+
+Most often, @var{increment} is an increment expression, as in the
+example above.  But this is not required; it can be any expression
+whatever.  For example, this statement prints all the powers of 2
+between 1 and 100:
+
+@example
+for (i = 1; i <= 100; i *= 2)
+  print i
+@end example
+
+Any of the three expressions in the parentheses following the @code{for} may
+be omitted if there is nothing to be done there.  Thus, @w{@samp{for (;x
+> 0;)}} is equivalent to @w{@samp{while (x > 0)}}.  If the
+@var{condition} is omitted, it is treated as @var{true}, effectively
+yielding an @dfn{infinite loop} (i.e., a loop that will never
+terminate).@refill
+
+In most cases, a @code{for} loop is an abbreviation for a @code{while}
+loop, as shown here:
+
+@example
+@var{initialization}
+while (@var{condition}) @{
+  @var{body}
+  @var{increment}
+@}
+@end example
+
+@noindent
+The only exception is when the @code{continue} statement
+(@pxref{Continue Statement, ,The @code{continue} Statement}) is used
+inside the loop; changing a @code{for} statement to a @code{while}
+statement in this way can change the effect of the @code{continue}
+statement inside the loop.@refill
+
+There is an alternate version of the @code{for} loop, for iterating over
+all the indices of an array:
+
+@example
+for (i in array)
+    @var{do something with} array[i]
+@end example
+
+@noindent
+@xref{Arrays, ,Arrays in @code{awk}}, for more information on this
+version of the @code{for} loop.
+
+The @code{awk} language has a @code{for} statement in addition to a
+@code{while} statement because often a @code{for} loop is both less work to
+type and more natural to think of.  Counting the number of iterations is
+very common in loops.  It can be easier to think of this counting as part
+of looping rather than as something to do inside the loop.
+
+The next section has more complicated examples of @code{for} loops.
+
+@node Break Statement, Continue Statement, For Statement, Statements
+@section The @code{break} Statement
+@cindex @code{break} statement
+@cindex loops, exiting
+
+The @code{break} statement jumps out of the innermost @code{for},
+@code{while}, or @code{do}-@code{while} loop that encloses it.  The
+following example finds the smallest divisor of any integer, and also
+identifies prime numbers:@refill
+
+@smallexample
+awk '# find smallest divisor of num
+     @{ num = $1
+       for (div = 2; div*div <= num; div++)
+         if (num % div == 0)
+           break
+       if (num % div == 0)
+         printf "Smallest divisor of %d is %d\n", num, div
+       else
+         printf "%d is prime\n", num  @}'
+@end smallexample
+
+When the remainder is zero in the first @code{if} statement, @code{awk}
+immediately @dfn{breaks out} of the containing @code{for} loop.  This means
+that @code{awk} proceeds immediately to the statement following the loop
+and continues processing.  (This is very different from the @code{exit}
+statement which stops the entire @code{awk} program.  
+@xref{Exit Statement, ,The @code{exit} Statement}.)@refill
+
+Here is another program equivalent to the previous one.  It illustrates how
+the @var{condition} of a @code{for} or @code{while} could just as well be
+replaced with a @code{break} inside an @code{if}:
+
+@smallexample
+@group
+awk '# find smallest divisor of num
+     @{ num = $1
+       for (div = 2; ; div++) @{
+         if (num % div == 0) @{
+           printf "Smallest divisor of %d is %d\n", num, div
+           break
+         @}
+         if (div*div > num) @{
+           printf "%d is prime\n", num
+           break
+         @}
+       @}
+@}'
+@end group
+@end smallexample
+
+@node Continue Statement, Next Statement, Break Statement, Statements
+@section The @code{continue} Statement
+
+@cindex @code{continue} statement
+The @code{continue} statement, like @code{break}, is used only inside
+@code{for}, @code{while}, and @code{do}-@code{while} loops.  It skips
+over the rest of the loop body, causing the next cycle around the loop
+to begin immediately.  Contrast this with @code{break}, which jumps out
+of the loop altogether.  Here is an example:@refill
+
+@example
+# print names that don't contain the string "ignore"
+
+# first, save the text of each line
+@{ names[NR] = $0 @}
+
+# print what we're interested in
+END @{
+   for (x in names) @{
+       if (names[x] ~ /ignore/)
+           continue
+       print names[x]
+   @}
+@}
+@end example
+
+If one of the input records contains the string @samp{ignore}, this
+example skips the print statement for that record, and continues back to
+the first statement in the loop.
+
+This is not a practical example of @code{continue}, since it would be
+just as easy to write the loop like this:
+
+@example
+for (x in names)
+  if (names[x] !~ /ignore/)
+    print names[x]
+@end example
+
+@ignore
+from brennan@boeing.com:
+
+page 90, section 9.6.  The example is too artificial as
+the one line program
+
+	!/ignore/
+
+does the same thing.
+@end ignore
+@c ADR --- he's right, but don't worry about this for now
+
+The @code{continue} statement in a @code{for} loop directs @code{awk} to
+skip the rest of the body of the loop, and resume execution with the
+increment-expression of the @code{for} statement.  The following program
+illustrates this fact:@refill
+
+@example
+awk 'BEGIN @{
+     for (x = 0; x <= 20; x++) @{
+         if (x == 5)
+             continue
+         printf ("%d ", x)
+     @}
+     print ""
+@}'
+@end example
+
+@noindent
+This program prints all the numbers from 0 to 20, except for 5, for
+which the @code{printf} is skipped.  Since the increment @code{x++}
+is not skipped, @code{x} does not remain stuck at 5.  Contrast the
+@code{for} loop above with the @code{while} loop:
+
+@example
+awk 'BEGIN @{
+     x = 0
+     while (x <= 20) @{
+         if (x == 5)
+             continue
+         printf ("%d ", x)
+         x++
+     @}
+     print ""
+@}'
+@end example
+
+@noindent
+This program loops forever once @code{x} gets to 5.
+
+As described above, the @code{continue} statement has no meaning when
+used outside the body of a loop.  However, although it was never documented,
+historical implementations of @code{awk} have treated the @code{continue}
+statement outside of a loop as if it were a @code{next} statement
+(@pxref{Next Statement, ,The @code{next} Statement}).  
+By default, @code{gawk} silently supports this usage.  However, if
+@samp{-W posix} has been specified on the command line
+(@pxref{Command Line, ,Invoking @code{awk}}),
+it will be treated as an error, since the @sc{posix} standard specifies
+that @code{continue} should only be used inside the body of a loop.@refill
+
+@node Next Statement, Next File Statement, Continue Statement, Statements
+@section The @code{next} Statement
+@cindex @code{next} statement
+
+The @code{next} statement forces @code{awk} to immediately stop processing
+the current record and go on to the next record.  This means that no
+further rules are executed for the current record.  The rest of the
+current rule's action is not executed either.
+
+Contrast this with the effect of the @code{getline} function
+(@pxref{Getline, ,Explicit Input with @code{getline}}).  That too causes
+@code{awk} to read the next record immediately, but it does not alter the
+flow of control in any way.  So the rest of the current action executes
+with a new input record.
+
+At the highest level, @code{awk} program execution is a loop that reads
+an input record and then tests each rule's pattern against it.  If you
+think of this loop as a @code{for} statement whose body contains the
+rules, then the @code{next} statement is analogous to a @code{continue}
+statement: it skips to the end of the body of this implicit loop, and
+executes the increment (which reads another record).
+
+For example, if your @code{awk} program works only on records with four
+fields, and you don't want it to fail when given bad input, you might
+use this rule near the beginning of the program:
+
+@smallexample
+NF != 4 @{
+  printf("line %d skipped: doesn't have 4 fields", FNR) > "/dev/stderr"
+  next
+@}
+@end smallexample
+
+@noindent
+so that the following rules will not see the bad record.  The error
+message is redirected to the standard error output stream, as error
+messages should be.  @xref{Special Files, ,Standard I/O Streams}.
+
+According to the @sc{posix} standard, the behavior is undefined if
+the @code{next} statement is used in a @code{BEGIN} or @code{END} rule.
+@code{gawk} will treat it as a syntax error.
+
+If the @code{next} statement causes the end of the input to be reached,
+then the code in the @code{END} rules, if any, will be executed.
+@xref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}.
+
+@node Next File Statement, Exit Statement, Next Statement, Statements
+@section The @code{next file} Statement
+
+@cindex @code{next file} statement
+The @code{next file} statement is similar to the @code{next} statement.
+However, instead of abandoning processing of the current record, the
+@code{next file} statement instructs @code{awk} to stop processing the
+current data file.
+
+Upon execution of the @code{next file} statement, @code{FILENAME} is
+updated to the name of the next data file listed on the command line,
+@code{FNR} is reset to 1, and processing starts over with the first
+rule in the progam.  @xref{Built-in Variables}.
+
+If the @code{next file} statement causes the end of the input to be reached,
+then the code in the @code{END} rules, if any, will be executed.
+@xref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}.
+
+The @code{next file} statement is a @code{gawk} extension; it is not
+(currently) available in any other @code{awk} implementation.  You can
+simulate its behavior by creating a library file named @file{nextfile.awk},
+with the following contents.  (This sample program uses user-defined
+functions, a feature that has not been presented yet.
+@xref{User-defined, ,User-defined Functions},
+for more information.)@refill
+
+@smallexample
+# nextfile --- function to skip remaining records in current file
+
+# this should be read in before the "main" awk program
+
+function nextfile() @{ _abandon_ = FILENAME; next @}
+
+_abandon_ == FILENAME && FNR > 1   @{ next @}
+_abandon_ == FILENAME && FNR == 1  @{ _abandon_ = "" @}
+@end smallexample
+
+The @code{nextfile} function simply sets a ``private'' variable@footnote{Since
+all variables in @code{awk} are global, this program uses the common
+practice of prefixing the variable name with an underscore.  In fact, it
+also suffixes the variable name with an underscore, as extra insurance
+against using a variable name that might be used in some other library
+file.} to the name of the current data file, and then retrieves the next
+record.  Since this file is read before the main @code{awk} program,
+the rules that follows the function definition will be executed before the
+rules in the main program.  The first rule continues to skip records as long as
+the name of the input file has not changed, and this is not the first
+record in the file.  This rule is sufficient most of the time.  But what if
+the @emph{same} data file is named twice in a row on the command line?
+This rule would not process the data file the second time.  The second rule
+catches this case: If the data file name is what was being skipped, but
+@code{FNR} is 1, then this is the second time the file is being processed,
+and it should not be skipped.
+
+The @code{next file} statement would be useful if you have many data
+files to process, and due to the nature of the data, you expect that you
+would not want to process every record in the file.  In order to move on to
+the next data file, you would have to continue scanning the unwanted
+records (as described above).  The @code{next file} statement accomplishes
+this much more efficiently.
+
+@ignore
+Would it make sense down the road to nuke `next file' in favor of
+semantics that would make this work?
+
+        function nextfile() { ARGIND++ ; next }
+@end ignore
+
+@node Exit Statement,  , Next File Statement, Statements
+@section The @code{exit} Statement
+
+@cindex @code{exit} statement
+The @code{exit} statement causes @code{awk} to immediately stop
+executing the current rule and to stop processing input; any remaining input
+is ignored.@refill
+
+If an @code{exit} statement is executed from a @code{BEGIN} rule the
+program stops processing everything immediately.  No input records are
+read.  However, if an @code{END} rule is present, it is executed
+(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}).
+
+If @code{exit} is used as part of an @code{END} rule, it causes
+the program to stop immediately.
+
+An @code{exit} statement that is part of an ordinary rule (that is, not part
+of a @code{BEGIN} or @code{END} rule) stops the execution of any further
+automatic rules, but the @code{END} rule is executed if there is one.
+If you do not want the @code{END} rule to do its job in this case, you
+can set a variable to nonzero before the @code{exit} statement, and check
+that variable in the @code{END} rule.
+
+If an argument is supplied to @code{exit}, its value is used as the exit
+status code for the @code{awk} process.  If no argument is supplied,
+@code{exit} returns status zero (success).@refill
+
+For example, let's say you've discovered an error condition you really
+don't know how to handle.  Conventionally, programs report this by
+exiting with a nonzero status.  Your @code{awk} program can do this
+using an @code{exit} statement with a nonzero argument.  Here's an
+example of this:@refill
+
+@example
+@group
+BEGIN @{
+       if (("date" | getline date_now) < 0) @{
+         print "Can't get system date" > "/dev/stderr"
+         exit 4
+       @}
+@}
+@end group
+@end example
+
+@node Arrays, Built-in, Statements, Top
+@chapter Arrays in @code{awk}
+
+An @dfn{array} is a table of values, called @dfn{elements}.  The
+elements of an array are distinguished by their indices.  @dfn{Indices}
+may be either numbers or strings.  Each array has a name, which looks
+like a variable name, but must not be in use as a variable name in the
+same @code{awk} program.
+
+@menu
+* Array Intro::                 Introduction to Arrays
+* Reference to Elements::       How to examine one element of an array.
+* Assigning Elements::          How to change an element of an array.
+* Array Example::               Basic Example of an Array
+* Scanning an Array::           A variation of the @code{for} statement.  
+                                It loops through the indices of 
+                                an array's existing elements.
+* Delete::                      The @code{delete} statement removes 
+                                an element from an array.
+* Numeric Array Subscripts::    How to use numbers as subscripts in @code{awk}.
+* Multi-dimensional::           Emulating multi-dimensional arrays in @code{awk}.
+* Multi-scanning::              Scanning multi-dimensional arrays.
+@end menu
+
+@node Array Intro, Reference to Elements, Arrays, Arrays
+@section Introduction to Arrays
+
+@cindex arrays
+The @code{awk} language has one-dimensional @dfn{arrays} for storing groups
+of related strings or numbers.
+
+Every @code{awk} array must have a name.  Array names have the same
+syntax as variable names; any valid variable name would also be a valid
+array name.  But you cannot use one name in both ways (as an array and
+as a variable) in one @code{awk} program.
+
+Arrays in @code{awk} superficially resemble arrays in other programming
+languages; but there are fundamental differences.  In @code{awk}, you
+don't need to specify the size of an array before you start to use it.
+Additionally, any number or string in @code{awk} may be used as an
+array index.
+
+In most other languages, you have to @dfn{declare} an array and specify
+how many elements or components it contains.  In such languages, the
+declaration causes a contiguous block of memory to be allocated for that
+many elements.  An index in the array must be a positive integer; for
+example, the index 0 specifies the first element in the array, which is
+actually stored at the beginning of the block of memory.  Index 1
+specifies the second element, which is stored in memory right after the
+first element, and so on.  It is impossible to add more elements to the
+array, because it has room for only as many elements as you declared.
+
+A contiguous array of four elements might look like this,
+conceptually, if the element values are @code{8}, @code{"foo"},
+@code{""} and @code{30}:@refill
+
+@example
++---------+---------+--------+---------+
+|    8    |  "foo"  |   ""   |    30   |    @r{value}
++---------+---------+--------+---------+
+     0         1         2         3        @r{index}
+@end example
+
+@noindent
+Only the values are stored; the indices are implicit from the order of
+the values.  @code{8} is the value at index 0, because @code{8} appears in the
+position with 0 elements before it.
+
+@cindex arrays, definition of
+@cindex associative arrays
+Arrays in @code{awk} are different: they are @dfn{associative}.  This means
+that each array is a collection of pairs: an index, and its corresponding
+array element value:
+
+@example
+@r{Element} 4     @r{Value} 30
+@r{Element} 2     @r{Value} "foo"
+@r{Element} 1     @r{Value} 8
+@r{Element} 3     @r{Value} ""
+@end example
+
+@noindent
+We have shown the pairs in jumbled order because their order is irrelevant.
+
+One advantage of an associative array is that new pairs can be added
+at any time.  For example, suppose we add to the above array a tenth element
+whose value is @w{@code{"number ten"}}.  The result is this:
+
+@example
+@r{Element} 10    @r{Value} "number ten"
+@r{Element} 4     @r{Value} 30
+@r{Element} 2     @r{Value} "foo"
+@r{Element} 1     @r{Value} 8
+@r{Element} 3     @r{Value} ""
+@end example
+
+@noindent
+Now the array is @dfn{sparse} (i.e., some indices are missing): it has
+elements 1--4 and 10, but doesn't have elements 5, 6, 7, 8, or 9.@refill
+
+Another consequence of associative arrays is that the indices don't
+have to be positive integers.  Any number, or even a string, can be
+an index.  For example, here is an array which translates words from
+English into French:
+
+@example
+@r{Element} "dog" @r{Value} "chien"
+@r{Element} "cat" @r{Value} "chat"
+@r{Element} "one" @r{Value} "un"
+@r{Element} 1     @r{Value} "un"
+@end example
+
+@noindent
+Here we decided to translate the number 1 in both spelled-out and
+numeric form---thus illustrating that a single array can have both
+numbers and strings as indices.
+
+When @code{awk} creates an array for you, e.g., with the @code{split}
+built-in function,
+that array's indices are consecutive integers starting at 1.
+(@xref{String Functions, ,Built-in Functions for String Manipulation}.)
+
+@node Reference to Elements, Assigning Elements, Array Intro, Arrays
+@section Referring to an Array Element
+@cindex array reference
+@cindex element of array
+@cindex reference to array
+
+The principal way of using an array is to refer to one of its elements.
+An array reference is an expression which looks like this:
+
+@example
+@var{array}[@var{index}]
+@end example
+
+@noindent
+Here, @var{array} is the name of an array.  The expression @var{index} is
+the index of the element of the array that you want.
+
+The value of the array reference is the current value of that array
+element.  For example, @code{foo[4.3]} is an expression for the element
+of array @code{foo} at index 4.3.
+
+If you refer to an array element that has no recorded value, the value
+of the reference is @code{""}, the null string.  This includes elements
+to which you have not assigned any value, and elements that have been
+deleted (@pxref{Delete, ,The @code{delete} Statement}).  Such a reference
+automatically creates that array element, with the null string as its value.
+(In some cases, this is unfortunate, because it might waste memory inside
+@code{awk}).
+
+@cindex arrays, presence of elements
+You can find out if an element exists in an array at a certain index with
+the expression:
+
+@example
+@var{index} in @var{array}
+@end example
+
+@noindent
+This expression tests whether or not the particular index exists,
+without the side effect of creating that element if it is not present.
+The expression has the value 1 (true) if @code{@var{array}[@var{index}]}
+exists, and 0 (false) if it does not exist.@refill
+
+For example, to test whether the array @code{frequencies} contains the
+index @code{"2"}, you could write this statement:@refill
+
+@smallexample
+if ("2" in frequencies) print "Subscript \"2\" is present."
+@end smallexample
+
+Note that this is @emph{not} a test of whether or not the array
+@code{frequencies} contains an element whose @emph{value} is @code{"2"}.
+(There is no way to do that except to scan all the elements.)  Also, this
+@emph{does not} create @code{frequencies["2"]}, while the following
+(incorrect) alternative would do so:@refill
+
+@smallexample
+if (frequencies["2"] != "") print "Subscript \"2\" is present."
+@end smallexample
+
+@node Assigning Elements, Array Example, Reference to Elements, Arrays
+@section Assigning Array Elements
+@cindex array assignment
+@cindex element assignment
+
+Array elements are lvalues: they can be assigned values just like
+@code{awk} variables:
+
+@example
+@var{array}[@var{subscript}] = @var{value}
+@end example
+
+@noindent
+Here @var{array} is the name of your array.  The expression
+@var{subscript} is the index of the element of the array that you want
+to assign a value.  The expression @var{value} is the value you are
+assigning to that element of the array.@refill
+
+@node Array Example, Scanning an Array, Assigning Elements, Arrays
+@section Basic Example of an Array
+
+The following program takes a list of lines, each beginning with a line
+number, and prints them out in order of line number.  The line numbers are
+not in order, however, when they are first read:  they are scrambled.  This
+program sorts the lines by making an array using the line numbers as
+subscripts.  It then prints out the lines in sorted order of their numbers.
+It is a very simple program, and gets confused if it encounters repeated
+numbers, gaps, or lines that don't begin with a number.@refill
+
+@example
+@{
+  if ($1 > max)
+    max = $1
+  arr[$1] = $0
+@}
+
+END @{
+  for (x = 1; x <= max; x++)
+    print arr[x]
+@}
+@end example
+
+The first rule keeps track of the largest line number seen so far;
+it also stores each line into the array @code{arr}, at an index that
+is the line's number.
+
+The second rule runs after all the input has been read, to print out
+all the lines.
+
+When this program is run with the following input:
+
+@example
+5  I am the Five man
+2  Who are you?  The new number two!
+4  . . . And four on the floor
+1  Who is number one?
+3  I three you.
+@end example
+
+@noindent
+its output is this:
+
+@example
+1  Who is number one?
+2  Who are you?  The new number two!
+3  I three you.
+4  . . . And four on the floor
+5  I am the Five man
+@end example
+
+If a line number is repeated, the last line with a given number overrides
+the others.
+
+Gaps in the line numbers can be handled with an easy improvement to the
+program's @code{END} rule:
+
+@example
+END @{
+  for (x = 1; x <= max; x++)
+    if (x in arr)
+      print arr[x]
+@}
+@end example
+
+@node Scanning an Array, Delete, Array Example, Arrays
+@section Scanning all Elements of an Array
+@cindex @code{for (x in @dots{})}
+@cindex arrays, special @code{for} statement
+@cindex scanning an array
+
+In programs that use arrays, often you need a loop that executes
+once for each element of an array.  In other languages, where arrays are
+contiguous and indices are limited to positive integers, this is
+easy: the largest index is one less than the length of the array, and you can
+find all the valid indices by counting from zero up to that value.  This
+technique won't do the job in @code{awk}, since any number or string
+may be an array index.  So @code{awk} has a special kind of @code{for}
+statement for scanning an array:
+
+@example
+for (@var{var} in @var{array})
+  @var{body}
+@end example
+
+@noindent
+This loop executes @var{body} once for each different value that your
+program has previously used as an index in @var{array}, with the
+variable @var{var} set to that index.@refill
+
+Here is a program that uses this form of the @code{for} statement.  The
+first rule scans the input records and notes which words appear (at
+least once) in the input, by storing a 1 into the array @code{used} with
+the word as index.  The second rule scans the elements of @code{used} to
+find all the distinct words that appear in the input.  It prints each
+word that is more than 10 characters long, and also prints the number of
+such words.  @xref{Built-in, ,Built-in Functions}, for more information
+on the built-in function @code{length}.
+
+@smallexample
+# Record a 1 for each word that is used at least once.
+@{
+  for (i = 1; i <= NF; i++)
+    used[$i] = 1
+@}
+
+# Find number of distinct words more than 10 characters long.
+END @{
+  for (x in used)
+    if (length(x) > 10) @{
+      ++num_long_words
+      print x
+  @}
+  print num_long_words, "words longer than 10 characters"
+@}
+@end smallexample
+
+@noindent
+@xref{Sample Program}, for a more detailed example of this type.
+
+The order in which elements of the array are accessed by this statement
+is determined by the internal arrangement of the array elements within
+@code{awk} and cannot be controlled or changed.  This can lead to
+problems if new elements are added to @var{array} by statements in
+@var{body}; you cannot predict whether or not the @code{for} loop will
+reach them.  Similarly, changing @var{var} inside the loop can produce
+strange results.  It is best to avoid such things.@refill
+
+@node Delete, Numeric Array Subscripts, Scanning an Array, Arrays
+@section The @code{delete} Statement
+@cindex @code{delete} statement
+@cindex deleting elements of arrays
+@cindex removing elements of arrays
+@cindex arrays, deleting an element
+
+You can remove an individual element of an array using the @code{delete}
+statement:
+
+@example
+delete @var{array}[@var{index}]
+@end example
+
+You can not refer to an array element after it has been deleted;
+it is as if you had never referred
+to it and had never given it any value.  You can no longer obtain any
+value the element once had.
+
+Here is an example of deleting elements in an array:
+
+@example
+for (i in frequencies)
+  delete frequencies[i]
+@end example
+
+@noindent
+This example removes all the elements from the array @code{frequencies}.
+
+If you delete an element, a subsequent @code{for} statement to scan the array
+will not report that element, and the @code{in} operator to check for
+the presence of that element will return 0:
+
+@example
+delete foo[4]
+if (4 in foo)
+  print "This will never be printed"
+@end example
+
+It is not an error to delete an element which does not exist.
+
+@node Numeric Array Subscripts, Multi-dimensional, Delete, Arrays
+@section Using Numbers to Subscript Arrays
+
+An important aspect of arrays to remember is that array subscripts
+are @emph{always} strings.  If you use a numeric value as a subscript,
+it will be converted to a string value before it is used for subscripting
+(@pxref{Conversion, ,Conversion of Strings and Numbers}).
+
+@cindex conversions, during subscripting
+@cindex numbers, used as subscripts
+@vindex CONVFMT
+This means that the value of the @code{CONVFMT} can potentially
+affect how your program accesses elements of an array.  For example:
+
+@example
+a = b = 12.153
+data[a] = 1
+CONVFMT = "%2.2f"
+if (b in data)
+    printf "%s is in data", b
+else
+    printf "%s is not in data", b
+@end example
+
+@noindent
+should print @samp{12.15 is not in data}.  The first statement gives
+both @code{a} and @code{b} the same numeric value.  Assigning to
+@code{data[a]} first gives @code{a} the string value @code{"12.153"}
+(using the default conversion value of @code{CONVFMT}, @code{"%.6g"}),
+and then assigns 1 to @code{data["12.153"]}.  The program then changes
+the value of @code{CONVFMT}.  The test @samp{(b in data)} forces @code{b}
+to be converted to a string, this time @code{"12.15"}, since the value of
+@code{CONVFMT} only allows two significant digits.  This test fails,
+since @code{"12.15"} is a different string from @code{"12.153"}.@refill
+
+According to the rules for conversions
+(@pxref{Conversion, ,Conversion of Strings and Numbers}), integer
+values are always converted to strings as integers, no matter what the
+value of @code{CONVFMT} may happen to be.  So the usual case of@refill
+
+@example
+for (i = 1; i <= maxsub; i++)
+    @i{do something with} array[i]
+@end example
+
+@noindent
+will work, no matter what the value of @code{CONVFMT}.
+
+Like many things in @code{awk}, the majority of the time things work
+as you would expect them to work.  But it is useful to have a precise
+knowledge of the actual rules, since sometimes they can have a subtle
+effect on your programs.
+
+@node Multi-dimensional, Multi-scanning, Numeric Array Subscripts, Arrays
+@section Multi-dimensional Arrays
+
+@c the following index entry is an overfull hbox.  --mew 30jan1992
+@cindex subscripts in arrays
+@cindex arrays, multi-dimensional subscripts
+@cindex multi-dimensional subscripts
+A multi-dimensional array is an array in which an element is identified
+by a sequence of indices, not a single index.  For example, a
+two-dimensional array requires two indices.  The usual way (in most
+languages, including @code{awk}) to refer to an element of a
+two-dimensional array named @code{grid} is with
+@code{grid[@var{x},@var{y}]}.
+
+@vindex SUBSEP
+Multi-dimensional arrays are supported in @code{awk} through
+concatenation of indices into one string.  What happens is that
+@code{awk} converts the indices into strings
+(@pxref{Conversion, ,Conversion of Strings and Numbers}) and
+concatenates them together, with a separator between them.  This creates
+a single string that describes the values of the separate indices.  The
+combined string is used as a single index into an ordinary,
+one-dimensional array.  The separator used is the value of the built-in
+variable @code{SUBSEP}.@refill
+
+For example, suppose we evaluate the expression @code{foo[5,12]="value"}
+when the value of @code{SUBSEP} is @code{"@@"}.  The numbers 5 and 12 are
+converted to strings and
+concatenated with an @samp{@@} between them, yielding @code{"5@@12"}; thus,
+the array element @code{foo["5@@12"]} is set to @code{"value"}.@refill
+
+Once the element's value is stored, @code{awk} has no record of whether
+it was stored with a single index or a sequence of indices.  The two
+expressions @code{foo[5,12]} and @w{@code{foo[5 SUBSEP 12]}} always have
+the same value.
+
+The default value of @code{SUBSEP} is the string @code{"\034"},
+which contains a nonprinting character that is unlikely to appear in an
+@code{awk} program or in the input data.
+
+The usefulness of choosing an unlikely character comes from the fact
+that index values that contain a string matching @code{SUBSEP} lead to
+combined strings that are ambiguous.  Suppose that @code{SUBSEP} were
+@code{"@@"}; then @w{@code{foo["a@@b", "c"]}} and @w{@code{foo["a",
+"b@@c"]}} would be indistinguishable because both would actually be
+stored as @code{foo["a@@b@@c"]}.  Because @code{SUBSEP} is
+@code{"\034"}, such confusion can arise only when an index
+contains the character with ASCII code 034, which is a rare
+event.@refill
+
+You can test whether a particular index-sequence exists in a
+``multi-dimensional'' array with the same operator @code{in} used for single
+dimensional arrays.  Instead of a single index as the left-hand operand,
+write the whole sequence of indices, separated by commas, in
+parentheses:@refill
+
+@example
+(@var{subscript1}, @var{subscript2}, @dots{}) in @var{array}
+@end example
+
+The following example treats its input as a two-dimensional array of
+fields; it rotates this array 90 degrees clockwise and prints the
+result.  It assumes that all lines have the same number of
+elements.
+
+@example
+awk '@{
+     if (max_nf < NF)
+          max_nf = NF
+     max_nr = NR
+     for (x = 1; x <= NF; x++)
+          vector[x, NR] = $x
+@}
+
+END @{
+     for (x = 1; x <= max_nf; x++) @{
+          for (y = max_nr; y >= 1; --y)
+               printf("%s ", vector[x, y])
+          printf("\n")
+     @}
+@}'
+@end example
+
+@noindent
+When given the input:
+
+@example
+@group
+1 2 3 4 5 6
+2 3 4 5 6 1
+3 4 5 6 1 2
+4 5 6 1 2 3
+@end group
+@end example
+
+@noindent
+it produces:
+
+@example
+@group
+4 3 2 1
+5 4 3 2
+6 5 4 3
+1 6 5 4
+2 1 6 5
+3 2 1 6
+@end group
+@end example
+
+@node Multi-scanning,  , Multi-dimensional, Arrays
+@section Scanning Multi-dimensional Arrays
+
+There is no special @code{for} statement for scanning a
+``multi-dimensional'' array; there cannot be one, because in truth there
+are no multi-dimensional arrays or elements; there is only a
+multi-dimensional @emph{way of accessing} an array.
+
+However, if your program has an array that is always accessed as
+multi-dimensional, you can get the effect of scanning it by combining
+the scanning @code{for} statement
+(@pxref{Scanning an Array, ,Scanning all Elements of an Array}) with the
+@code{split} built-in function
+(@pxref{String Functions, ,Built-in Functions for String Manipulation}).
+It works like this:@refill
+
+@example
+for (combined in @var{array}) @{
+  split(combined, separate, SUBSEP)
+  @dots{}
+@}
+@end example
+
+@noindent
+This finds each concatenated, combined index in the array, and splits it
+into the individual indices by breaking it apart where the value of
+@code{SUBSEP} appears.  The split-out indices become the elements of
+the array @code{separate}.
+
+Thus, suppose you have previously stored in @code{@var{array}[1,
+"foo"]}; then an element with index @code{"1\034foo"} exists in
+@var{array}.  (Recall that the default value of @code{SUBSEP} contains
+the character with code 034.)  Sooner or later the @code{for} statement
+will find that index and do an iteration with @code{combined} set to
+@code{"1\034foo"}.  Then the @code{split} function is called as
+follows:
+
+@example
+split("1\034foo", separate, "\034")
+@end example
+
+@noindent
+The result of this is to set @code{separate[1]} to 1 and @code{separate[2]}
+to @code{"foo"}.  Presto, the original sequence of separate indices has
+been recovered.
+
+@node Built-in, User-defined, Arrays, Top
+@chapter Built-in Functions
+
+@cindex built-in functions
+@dfn{Built-in} functions are functions that are always available for
+your @code{awk} program to call.  This chapter defines all the built-in
+functions in @code{awk}; some of them are mentioned in other sections,
+but they are summarized here for your convenience.  (You can also define
+new functions yourself.  @xref{User-defined, ,User-defined Functions}.)
+
+@menu
+* Calling Built-in::            How to call built-in functions.
+* Numeric Functions::           Functions that work with numbers,
+                                including @code{int}, @code{sin} and @code{rand}.
+* String Functions::            Functions for string manipulation,
+                                such as @code{split}, @code{match}, and @code{sprintf}.
+* I/O Functions::               Functions for files and shell commands.
+* Time Functions::              Functions for dealing with time stamps.
+@end menu
+
+@node Calling Built-in, Numeric Functions, Built-in, Built-in
+@section Calling Built-in Functions
+
+To call a built-in function, write the name of the function followed
+by arguments in parentheses.  For example, @code{atan2(y + z, 1)}
+is a call to the function @code{atan2}, with two arguments.
+
+Whitespace is ignored between the built-in function name and the
+open-parenthesis, but we recommend that you avoid using whitespace
+there.  User-defined functions do not permit whitespace in this way, and
+you will find it easier to avoid mistakes by following a simple
+convention which always works: no whitespace after a function name.
+
+Each built-in function accepts a certain number of arguments.  In most
+cases, any extra arguments given to built-in functions are ignored.  The
+defaults for omitted arguments vary from function to function and are
+described under the individual functions.
+
+When a function is called, expressions that create the function's actual
+parameters are evaluated completely before the function call is performed.
+For example, in the code fragment:
+
+@example
+i = 4
+j = sqrt(i++)
+@end example
+
+@noindent
+the variable @code{i} is set to 5 before @code{sqrt} is called
+with a value of 4 for its actual parameter.
+
+@node Numeric Functions, String Functions, Calling Built-in, Built-in
+@section Numeric Built-in Functions
+@c I didn't make all the examples small because a couple of them were
+@c short already. --mew 29jan1992
+
+Here is a full list of built-in functions that work with numbers:
+
+@table @code
+@item int(@var{x})
+This gives you the integer part of @var{x}, truncated toward 0.  This
+produces the nearest integer to @var{x}, located between @var{x} and 0.
+
+For example, @code{int(3)} is 3, @code{int(3.9)} is 3, @code{int(-3.9)}
+is @minus{}3, and @code{int(-3)} is @minus{}3 as well.@refill
+
+@item sqrt(@var{x})
+This gives you the positive square root of @var{x}.  It reports an error
+if @var{x} is negative.  Thus, @code{sqrt(4)} is 2.@refill
+
+@item exp(@var{x})
+This gives you the exponential of @var{x}, or reports an error if
+@var{x} is out of range.  The range of values @var{x} can have depends
+on your machine's floating point representation.@refill
+
+@item log(@var{x})
+This gives you the natural logarithm of @var{x}, if @var{x} is positive;
+otherwise, it reports an error.@refill
+
+@item sin(@var{x})
+This gives you the sine of @var{x}, with @var{x} in radians.
+
+@item cos(@var{x})
+This gives you the cosine of @var{x}, with @var{x} in radians.
+
+@item atan2(@var{y}, @var{x})
+This gives you the arctangent of @code{@var{y} / @var{x}} in radians.
+
+@item rand()
+This gives you a random number.  The values of @code{rand} are
+uniformly-distributed between 0 and 1.  The value is never 0 and never
+1.
+
+Often you want random integers instead.  Here is a user-defined function
+you can use to obtain a random nonnegative integer less than @var{n}:
+
+@example
+function randint(n) @{
+     return int(n * rand())
+@}
+@end example
+
+@noindent
+The multiplication produces a random real number greater than 0 and less
+than @var{n}.  We then make it an integer (using @code{int}) between 0
+and @code{@var{n} @minus{} 1}.
+
+Here is an example where a similar function is used to produce
+random integers between 1 and @var{n}.  Note that this program will
+print a new random number for each input record.
+
+@smallexample
+awk '
+# Function to roll a simulated die.
+function roll(n) @{ return 1 + int(rand() * n) @}
+
+# Roll 3 six-sided dice and print total number of points.
+@{
+      printf("%d points\n", roll(6)+roll(6)+roll(6))
+@}'
+@end smallexample
+
+@strong{Note:} @code{rand} starts generating numbers from the same
+point, or @dfn{seed}, each time you run @code{awk}.  This means that
+a program will produce the same results each time you run it.
+The numbers are random within one @code{awk} run, but predictable
+from run to run.  This is convenient for debugging, but if you want
+a program to do different things each time it is used, you must change
+the seed to a value that will be different in each run.  To do this,
+use @code{srand}.
+
+@item srand(@var{x})
+The function @code{srand} sets the starting point, or @dfn{seed},
+for generating random numbers to the value @var{x}.
+
+Each seed value leads to a particular sequence of ``random'' numbers.
+Thus, if you set the seed to the same value a second time, you will get
+the same sequence of ``random'' numbers again.
+
+If you omit the argument @var{x}, as in @code{srand()}, then the current
+date and time of day are used for a seed.  This is the way to get random
+numbers that are truly unpredictable.
+
+The return value of @code{srand} is the previous seed.  This makes it
+easy to keep track of the seeds for use in consistently reproducing
+sequences of random numbers.
+@end table
+
+@node String Functions, I/O Functions, Numeric Functions, Built-in
+@section Built-in Functions for String Manipulation
+
+The functions in this section look at or change the text of one or more
+strings.
+
+@table @code
+@item index(@var{in}, @var{find})
+@findex match
+This searches the string @var{in} for the first occurrence of the string
+@var{find}, and returns the position in characters where that occurrence
+begins in the string @var{in}.  For example:@refill
+
+@smallexample
+awk 'BEGIN @{ print index("peanut", "an") @}'
+@end smallexample
+
+@noindent
+prints @samp{3}.  If @var{find} is not found, @code{index} returns 0.
+(Remember that string indices in @code{awk} start at 1.)
+
+@item length(@var{string})
+@findex length
+This gives you the number of characters in @var{string}.  If
+@var{string} is a number, the length of the digit string representing
+that number is returned.  For example, @code{length("abcde")} is 5.  By
+contrast, @code{length(15 * 35)} works out to 3.  How?  Well, 15 * 35 =
+525, and 525 is then converted to the string @samp{"525"}, which has
+three characters.
+
+If no argument is supplied, @code{length} returns the length of @code{$0}.
+
+In older versions of @code{awk}, you could call the @code{length} function
+without any parentheses.  Doing so is marked as ``deprecated'' in the
+@sc{posix} standard.  This means that while you can do this in your
+programs, it is a feature that can eventually be removed from a future
+version of the standard.  Therefore, for maximal portability of your
+@code{awk} programs you should always supply the parentheses.
+
+@item match(@var{string}, @var{regexp})
+@findex match
+The @code{match} function searches the string, @var{string}, for the
+longest, leftmost substring matched by the regular expression,
+@var{regexp}.  It returns the character position, or @dfn{index}, of
+where that substring begins (1, if it starts at the beginning of
+@var{string}).  If no match if found, it returns 0.
+
+@vindex RSTART
+@vindex RLENGTH
+The @code{match} function sets the built-in variable @code{RSTART} to
+the index.  It also sets the built-in variable @code{RLENGTH} to the
+length in characters of the matched substring.  If no match is found,
+@code{RSTART} is set to 0, and @code{RLENGTH} to @minus{}1.
+
+For example:
+
+@smallexample
+awk '@{
+       if ($1 == "FIND")
+         regex = $2
+       else @{
+         where = match($0, regex)
+         if (where)
+           print "Match of", regex, "found at", where, "in", $0
+       @}
+@}'
+@end smallexample
+
+@noindent
+This program looks for lines that match the regular expression stored in
+the variable @code{regex}.  This regular expression can be changed.  If the
+first word on a line is @samp{FIND}, @code{regex} is changed to be the
+second word on that line.  Therefore, given:
+
+@smallexample
+FIND fo*bar
+My program was a foobar
+But none of it would doobar
+FIND Melvin
+JF+KM
+This line is property of The Reality Engineering Co.
+This file created by Melvin.
+@end smallexample
+
+@noindent
+@code{awk} prints:
+
+@smallexample
+Match of fo*bar found at 18 in My program was a foobar
+Match of Melvin found at 26 in This file created by Melvin.
+@end smallexample
+
+@item split(@var{string}, @var{array}, @var{fieldsep})
+@findex split
+This divides @var{string} into pieces separated by @var{fieldsep},
+and stores the pieces in @var{array}.  The first piece is stored in
+@code{@var{array}[1]}, the second piece in @code{@var{array}[2]}, and so
+forth.  The string value of the third argument, @var{fieldsep}, is
+a regexp describing where to split @var{string} (much as @code{FS} can
+be a regexp describing where to split input records).  If
+the @var{fieldsep} is omitted, the value of @code{FS} is used.
+@code{split} returns the number of elements created.@refill
+
+The @code{split} function, then, splits strings into pieces in a
+manner similar to the way input lines are split into fields.  For example:
+
+@smallexample
+split("auto-da-fe", a, "-")
+@end smallexample
+
+@noindent
+splits the string @samp{auto-da-fe} into three fields using @samp{-} as the
+separator.  It sets the contents of the array @code{a} as follows:
+
+@smallexample
+a[1] = "auto"
+a[2] = "da"
+a[3] = "fe"
+@end smallexample
+
+@noindent
+The value returned by this call to @code{split} is 3.
+
+As with input field-splitting, when the value of @var{fieldsep} is
+@code{" "}, leading and trailing whitespace is ignored, and the elements
+are separated by runs of whitespace.
+
+@item sprintf(@var{format}, @var{expression1},@dots{})
+@findex sprintf
+This returns (without printing) the string that @code{printf} would
+have printed out with the same arguments
+(@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing}).
+For example:@refill
+
+@smallexample
+sprintf("pi = %.2f (approx.)", 22/7)
+@end smallexample
+
+@noindent
+returns the string @w{@code{"pi = 3.14 (approx.)"}}.
+
+@item sub(@var{regexp}, @var{replacement}, @var{target})
+@findex sub
+The @code{sub} function alters the value of @var{target}.
+It searches this value, which should be a string, for the
+leftmost substring matched by the regular expression, @var{regexp},
+extending this match as far as possible.  Then the entire string is
+changed by replacing the matched text with @var{replacement}.
+The modified string becomes the new value of @var{target}.
+
+This function is peculiar because @var{target} is not simply
+used to compute a value, and not just any expression will do: it
+must be a variable, field or array reference, so that @code{sub} can
+store a modified value there.  If this argument is omitted, then the
+default is to use and alter @code{$0}.
+
+For example:@refill
+
+@smallexample
+str = "water, water, everywhere"
+sub(/at/, "ith", str)
+@end smallexample
+
+@noindent
+sets @code{str} to @w{@code{"wither, water, everywhere"}}, by replacing the
+leftmost, longest occurrence of @samp{at} with @samp{ith}.
+
+The @code{sub} function returns the number of substitutions made (either
+one or zero).
+
+If the special character @samp{&} appears in @var{replacement}, it
+stands for the precise substring that was matched by @var{regexp}.  (If
+the regexp can match more than one string, then this precise substring
+may vary.)  For example:@refill
+
+@smallexample
+awk '@{ sub(/candidate/, "& and his wife"); print @}'
+@end smallexample
+
+@noindent
+changes the first occurrence of @samp{candidate} to @samp{candidate
+and his wife} on each input line.
+
+Here is another example:
+
+@smallexample
+awk 'BEGIN @{
+        str = "daabaaa"
+        sub(/a*/, "c&c", str)
+        print str
+@}'
+@end smallexample
+
+@noindent
+prints @samp{dcaacbaaa}.  This show how @samp{&} can represent a non-constant
+string, and also illustrates the ``leftmost, longest'' rule.
+
+The effect of this special character (@samp{&}) can be turned off by putting a
+backslash before it in the string.  As usual, to insert one backslash in
+the string, you must write two backslashes.  Therefore, write @samp{\\&}
+in a string constant to include a literal @samp{&} in the replacement.
+For example, here is how to replace the first @samp{|} on each line with
+an @samp{&}:@refill
+
+@smallexample
+awk '@{ sub(/\|/, "\\&"); print @}'
+@end smallexample
+
+@strong{Note:} as mentioned above, the third argument to @code{sub} must
+be an lvalue.  Some versions of @code{awk} allow the third argument to
+be an expression which is not an lvalue.  In such a case, @code{sub}
+would still search for the pattern and return 0 or 1, but the result of
+the substitution (if any) would be thrown away because there is no place
+to put it.  Such versions of @code{awk} accept expressions like
+this:@refill
+
+@smallexample
+sub(/USA/, "United States", "the USA and Canada")
+@end smallexample
+
+@noindent
+But that is considered erroneous in @code{gawk}.
+
+@item gsub(@var{regexp}, @var{replacement}, @var{target})
+@findex gsub
+This is similar to the @code{sub} function, except @code{gsub} replaces
+@emph{all} of the longest, leftmost, @emph{nonoverlapping} matching
+substrings it can find.  The @samp{g} in @code{gsub} stands for
+``global,'' which means replace everywhere.  For example:@refill
+
+@smallexample
+awk '@{ gsub(/Britain/, "United Kingdom"); print @}'
+@end smallexample
+
+@noindent
+replaces all occurrences of the string @samp{Britain} with @samp{United
+Kingdom} for all input records.@refill
+
+The @code{gsub} function returns the number of substitutions made.  If
+the variable to be searched and altered, @var{target}, is
+omitted, then the entire input record, @code{$0}, is used.@refill
+
+As in @code{sub}, the characters @samp{&} and @samp{\} are special, and
+the third argument must be an lvalue.
+
+@item substr(@var{string}, @var{start}, @var{length})
+@findex substr
+This returns a @var{length}-character-long substring of @var{string},
+starting at character number @var{start}.  The first character of a
+string is character number one.  For example,
+@code{substr("washington", 5, 3)} returns @code{"ing"}.@refill
+
+If @var{length} is not present, this function returns the whole suffix of
+@var{string} that begins at character number @var{start}.  For example,
+@code{substr("washington", 5)} returns @code{"ington"}.  This is also
+the case if @var{length} is greater than the number of characters remaining
+in the string, counting from character number @var{start}.
+
+@item tolower(@var{string})
+@findex tolower
+This returns a copy of @var{string}, with each upper-case character
+in the string replaced with its corresponding lower-case character.
+Nonalphabetic characters are left unchanged.  For example,
+@code{tolower("MiXeD cAsE 123")} returns @code{"mixed case 123"}.
+
+@item toupper(@var{string})
+@findex toupper
+This returns a copy of @var{string}, with each lower-case character
+in the string replaced with its corresponding upper-case character.
+Nonalphabetic characters are left unchanged.  For example,
+@code{toupper("MiXeD cAsE 123")} returns @code{"MIXED CASE 123"}.
+@end table
+
+@node I/O Functions, Time Functions, String Functions, Built-in
+@section Built-in Functions for Input/Output
+
+@table @code
+@item close(@var{filename})
+Close the file @var{filename}, for input or output.  The argument may
+alternatively be a shell command that was used for redirecting to or
+from a pipe; then the pipe is closed.
+
+@xref{Close Input, ,Closing Input Files and Pipes}, regarding closing
+input files and pipes.  @xref{Close Output, ,Closing Output Files and Pipes},
+regarding closing output files and pipes.@refill
+
+@item system(@var{command})
+@findex system
+@c the following index entry is an overfull hbox.  --mew 30jan1992
+@cindex interaction, @code{awk} and other programs
+The system function allows the user to execute operating system commands
+and then return to the @code{awk} program.  The @code{system} function
+executes the command given by the string @var{command}.  It returns, as
+its value, the status returned by the command that was executed.
+
+For example, if the following fragment of code is put in your @code{awk}
+program:
+
+@smallexample
+END @{
+     system("mail -s 'awk run done' operator < /dev/null")
+@}
+@end smallexample
+
+@noindent
+the system operator will be sent mail when the @code{awk} program
+finishes processing input and begins its end-of-input processing.
+
+Note that much the same result can be obtained by redirecting
+@code{print} or @code{printf} into a pipe.  However, if your @code{awk}
+program is interactive, @code{system} is useful for cranking up large
+self-contained programs, such as a shell or an editor.@refill
+
+Some operating systems cannot implement the @code{system} function.
+@code{system} causes a fatal error if it is not supported.
+@end table
+
+@c fakenode --- for prepinfo
+@subheading Controlling Output Buffering with @code{system}
+@cindex flushing buffers
+@cindex buffers, flushing
+@cindex buffering output
+@cindex output, buffering
+
+Many utility programs will @dfn{buffer} their output; they save information
+to be written to a disk file or terminal in memory, until there is enough
+to be written in one operation.  This is often more efficient than writing
+every little bit of information as soon as it is ready.  However, sometimes
+it is necessary to force a program to @dfn{flush} its buffers; that is,
+write the information to its destination, even if a buffer is not full.
+You can do this from your @code{awk} program by calling @code{system}
+with a null string as its argument:
+
+@example
+system("")   # flush output
+@end example
+
+@noindent
+@code{gawk} treats this use of the @code{system} function as a special
+case, and is smart enough not to run a shell (or other command
+interpreter) with the empty command.  Therefore, with @code{gawk}, this
+idiom is not only useful, it is efficient.  While this idiom should work
+with other @code{awk} implementations, it will not necessarily avoid
+starting an unnecessary shell.
+@ignore
+Need a better explanation, perhaps in a separate paragraph.  Explain that
+for
+
+awk 'BEGIN { print "hi"
+             system("echo hello")
+             print "howdy" }'
+
+that the output had better be
+
+             hi
+             hello
+             howdy
+
+and not
+
+             hello
+             hi
+             howdy
+
+which it would be if awk did not flush its buffers before calling system.
+@end ignore
+
+@node Time Functions,  , I/O Functions, Built-in
+@section Functions for Dealing with Time Stamps
+
+@cindex time stamps
+@cindex time of day
+A common use for @code{awk} programs is the processing of log files.
+Log files often contain time stamp information, indicating when a
+particular log record was written.  Many programs log their time stamp
+in the form returned by the @code{time} system call, which is the
+number of seconds since a particular epoch.  On @sc{posix} systems,
+it is the number of seconds since Midnight, January 1, 1970, @sc{utc}.
+
+In order to make it easier to process such log files, and to easily produce
+useful reports, @code{gawk} provides two functions for working with time
+stamps.  Both of these are @code{gawk} extensions; they are not specified
+in the @sc{posix} standard, nor are they in any other known version
+of @code{awk}.
+
+@table @code
+@item systime()
+@findex systime
+This function returns the current time as the number of seconds since
+the system epoch.  On @sc{posix} systems, this is the number of seconds
+since Midnight, January 1, 1970, @sc{utc}.  It may be a different number on
+other systems.
+
+@item strftime(@var{format}, @var{timestamp})
+@findex strftime
+This function returns a string.  It is similar to the function of the
+same name in the @sc{ansi} C standard library.  The time specified by
+@var{timestamp} is used to produce a string, based on the contents
+of the @var{format} string.
+@end table
+
+The @code{systime} function allows you to compare a time stamp from a
+log file with the current time of day.  In particular, it is easy to
+determine how long ago a particular record was logged.  It also allows
+you to produce log records using the ``seconds since the epoch'' format.
+
+The @code{strftime} function allows you to easily turn a time stamp
+into human-readable information.  It is similar in nature to the @code{sprintf}
+function, copying non-format specification characters verbatim to the
+returned string, and substituting date and time values for format
+specifications in the @var{format} string.  If no @var{timestamp} argument
+is supplied, @code{gawk} will use the current time of day as the
+time stamp.@refill
+
+@code{strftime} is guaranteed by the @sc{ansi} C standard to support
+the following date format specifications:
+
+@table @code
+@item %a
+The locale's abbreviated weekday name.
+
+@item %A
+The locale's full weekday name.
+
+@item %b
+The locale's abbreviated month name.
+
+@item %B
+The locale's full month name.
+
+@item %c
+The locale's ``appropriate'' date and time representation.
+
+@item %d
+The day of the month as a decimal number (01--31).
+
+@item %H
+The hour (24-hour clock) as a decimal number (00--23).
+
+@item %I
+The hour (12-hour clock) as a decimal number (01--12).
+
+@item %j
+The day of the year as a decimal number (001--366).
+
+@item %m
+The month as a decimal number (01--12).
+
+@item %M
+The minute as a decimal number (00--59).
+
+@item %p
+The locale's equivalent of the AM/PM designations associated
+with a 12-hour clock.
+
+@item %S
+The second as a decimal number (00--61).  (Occasionally there are
+minutes in a year with one or two leap seconds, which is why the
+seconds can go from 0 all the way to 61.)
+
+@item %U
+The week number of the year (the first Sunday as the first day of week 1)
+as a decimal number (00--53).
+
+@item %w
+The weekday as a decimal number (0--6).  Sunday is day 0.
+
+@item %W
+The week number of the year (the first Monday as the first day of week 1)
+as a decimal number (00--53).
+
+@item %x
+The locale's ``appropriate'' date representation.
+
+@item %X
+The locale's ``appropriate'' time representation.
+
+@item %y
+The year without century as a decimal number (00--99).
+
+@item %Y
+The year with century as a decimal number.
+
+@item %Z
+The time zone name or abbreviation, or no characters if
+no time zone is determinable.
+
+@item %%
+A literal @samp{%}.
+@end table
+
+@c The parenthetical remark here should really be a footnote, but
+@c it gave formatting problems at the FSF. So for now put it in
+@c parentheses.
+If a conversion specifier is not one of the above, the behavior is
+undefined.  (This is because the @sc{ansi} standard for C leaves the
+behavior of the C version of @code{strftime} undefined, and @code{gawk}
+will use the system's version of @code{strftime} if it's there.
+Typically, the conversion specifier will either not appear in the
+returned string, or it will appear literally.)
+
+Informally, a @dfn{locale} is the geographic place in which a program
+is meant to run.  For example, a common way to abbreviate the date
+September 4, 1991 in the United States would be ``9/4/91''.
+In many countries in Europe, however, it would be abbreviated ``4.9.91''.
+Thus, the @samp{%x} specification in a @code{"US"} locale might produce
+@samp{9/4/91}, while in a @code{"EUROPE"} locale, it might produce
+@samp{4.9.91}.  The @sc{ansi} C standard defines a default @code{"C"}
+locale, which is an environment that is typical of what most C programmers
+are used to.
+
+A public-domain C version of @code{strftime} is shipped with @code{gawk}
+for systems that are not yet fully @sc{ansi}-compliant.  If that version is
+used to compile @code{gawk} (@pxref{Installation, ,Installing @code{gawk}}),
+then the following additional format specifications are available:@refill
+
+@table @code
+@item %D
+Equivalent to specifying @samp{%m/%d/%y}.
+
+@item %e
+The day of the month, padded with a blank if it is only one digit.
+
+@item %h
+Equivalent to @samp{%b}, above.
+
+@item %n
+A newline character (ASCII LF).
+
+@item %r
+Equivalent to specifying @samp{%I:%M:%S %p}.
+
+@item %R
+Equivalent to specifying @samp{%H:%M}.
+
+@item %T
+Equivalent to specifying @samp{%H:%M:%S}.
+
+@item %t
+A TAB character.
+
+@item %k
+is replaced by the hour (24-hour clock) as a decimal number (0-23).
+Single digit numbers are padded with a blank.
+
+@item %l
+is replaced by the hour (12-hour clock) as a decimal number (1-12).
+Single digit numbers are padded with a blank.
+
+@item %C
+The century, as a number between 00 and 99.
+
+@item %u
+is replaced by the weekday as a decimal number
+[1 (Monday)--7].
+
+@item %V
+is replaced by the week number of the year (the first Monday as the first
+day of week 1) as a decimal number (01--53).
+The method for determining the week number is as specified by ISO 8601
+(to wit: if the week containing January 1 has four or more days in the
+new year, then it is week 1, otherwise it is week 53 of the previous year
+and the next week is week 1).@refill
+
+@item %Ec %EC %Ex %Ey %EY %Od %Oe %OH %OI
+@itemx %Om %OM %OS %Ou %OU %OV %Ow %OW %Oy
+These are ``alternate representations'' for the specifications
+that use only the second letter (@samp{%c}, @samp{%C}, and so on).
+They are recognized, but their normal representations are used.
+(These facilitate compliance with the @sc{posix} @code{date}
+utility.)@refill
+
+@item %v
+The date in VMS format (e.g. 20-JUN-1991).
+@end table
+
+Here are two examples that use @code{strftime}.  The first is an
+@code{awk} version of the C @code{ctime} function.  (This is a
+user defined function, which we have not discussed yet.
+@xref{User-defined, ,User-defined Functions}, for more information.)
+
+@smallexample
+# ctime.awk
+#
+# awk version of C ctime(3) function
+
+function ctime(ts,    format)
+@{
+    format = "%a %b %e %H:%M:%S %Z %Y"
+    if (ts == 0)
+        ts = systime()         # use current time as default
+    return strftime(format, ts)
+@}
+@end smallexample
+
+This next example is an @code{awk} implementation of the @sc{posix}
+@code{date} utility.  Normally, the @code{date} utility prints the
+current date and time of day in a well known format.  However, if you
+provide an argument to it that begins with a @samp{+}, @code{date}
+will copy non-format specifier characters to the standard output, and
+will interpret the current time according to the format specifiers in
+the string.  For example:
+
+@smallexample
+date '+Today is %A, %B %d, %Y.'
+@end smallexample
+
+@noindent
+might print
+
+@smallexample
+Today is Thursday, July 11, 1991.
+@end smallexample
+
+Here is the @code{awk} version of the @code{date} utility.
+
+@smallexample
+#! /usr/bin/gawk -f
+#
+# date --- implement the P1003.2 Draft 11 'date' command
+#
+# Bug: does not recognize the -u argument.
+
+BEGIN    \
+@{
+    format = "%a %b %e %H:%M:%S %Z %Y"
+    exitval = 0
+
+    if (ARGC > 2)
+        exitval = 1
+    else if (ARGC == 2) @{
+        format = ARGV[1]
+        if (format ~ /^\+/)
+            format = substr(format, 2)    # remove leading +
+    @}
+    print strftime(format)
+    exit exitval
+@}
+@end smallexample
+
+@node User-defined, Built-in Variables, Built-in, Top
+@chapter User-defined Functions
+
+@cindex user-defined functions
+@cindex functions, user-defined
+Complicated @code{awk} programs can often be simplified by defining
+your own functions.  User-defined functions can be called just like
+built-in ones (@pxref{Function Calls}), but it is up to you to define
+them---to tell @code{awk} what they should do.
+
+@menu
+* Definition Syntax::           How to write definitions and what they mean.
+* Function Example::            An example function definition and 
+                                what it does.
+* Function Caveats::            Things to watch out for.
+* Return Statement::            Specifying the value a function returns.
+@end menu
+
+@node Definition Syntax, Function Example, User-defined, User-defined
+@section Syntax of Function Definitions
+@cindex defining functions
+@cindex function definition
+
+Definitions of functions can appear anywhere between the rules of the
+@code{awk} program.  Thus, the general form of an @code{awk} program is
+extended to include sequences of rules @emph{and} user-defined function
+definitions.
+
+The definition of a function named @var{name} looks like this:
+
+@example
+function @var{name} (@var{parameter-list}) @{
+     @var{body-of-function}
+@}
+@end example
+
+@noindent
+@var{name} is the name of the function to be defined.  A valid function
+name is like a valid variable name: a sequence of letters, digits and
+underscores, not starting with a digit.  Functions share the same pool
+of names as variables and arrays.
+
+@var{parameter-list} is a list of the function's arguments and local
+variable names, separated by commas.  When the function is called,
+the argument names are used to hold the argument values given in
+the call.  The local variables are initialized to the null string.
+
+The @var{body-of-function} consists of @code{awk} statements.  It is the
+most important part of the definition, because it says what the function
+should actually @emph{do}.  The argument names exist to give the body a
+way to talk about the arguments; local variables, to give the body
+places to keep temporary values.
+
+Argument names are not distinguished syntactically from local variable
+names; instead, the number of arguments supplied when the function is
+called determines how many argument variables there are.  Thus, if three
+argument values are given, the first three names in @var{parameter-list}
+are arguments, and the rest are local variables.
+
+It follows that if the number of arguments is not the same in all calls
+to the function, some of the names in @var{parameter-list} may be
+arguments on some occasions and local variables on others.  Another
+way to think of this is that omitted arguments default to the
+null string.
+
+Usually when you write a function you know how many names you intend to
+use for arguments and how many you intend to use as locals.  By
+convention, you should write an extra space between the arguments and
+the locals, so other people can follow how your function is
+supposed to be used.
+
+During execution of the function body, the arguments and local variable
+values hide or @dfn{shadow} any variables of the same names used in the
+rest of the program.  The shadowed variables are not accessible in the
+function definition, because there is no way to name them while their
+names have been taken away for the local variables.  All other variables
+used in the @code{awk} program can be referenced or set normally in the
+function definition.
+
+The arguments and local variables last only as long as the function body
+is executing.  Once the body finishes, the shadowed variables come back.
+
+The function body can contain expressions which call functions.  They
+can even call this function, either directly or by way of another
+function.  When this happens, we say the function is @dfn{recursive}.
+
+There is no need in @code{awk} to put the definition of a function
+before all uses of the function.  This is because @code{awk} reads the
+entire program before starting to execute any of it.
+
+In many @code{awk} implementations, the keyword @code{function} may be
+abbreviated @code{func}.  However, @sc{posix} only specifies the use of
+the keyword @code{function}.  This actually has some practical implications.
+If @code{gawk} is in @sc{posix}-compatibility mode
+(@pxref{Command Line, ,Invoking @code{awk}}), then the following
+statement will @emph{not} define a function:@refill
+
+@example
+func foo() @{ a = sqrt($1) ; print a @}
+@end example
+
+@noindent
+Instead it defines a rule that, for each record, concatenates the value
+of the variable @samp{func} with the return value of the function @samp{foo},
+and based on the truth value of the result, executes the corresponding action.
+This is probably not what was desired.  (@code{awk} accepts this input as
+syntactically valid, since functions may be used before they are defined
+in @code{awk} programs.)
+
+@node Function Example, Function Caveats, Definition Syntax, User-defined
+@section Function Definition Example
+
+Here is an example of a user-defined function, called @code{myprint}, that
+takes a number and prints it in a specific format.
+
+@example
+function myprint(num)
+@{
+     printf "%6.3g\n", num
+@}
+@end example
+
+@noindent
+To illustrate, here is an @code{awk} rule which uses our @code{myprint}
+function:
+
+@example
+$3 > 0     @{ myprint($3) @}
+@end example
+
+@noindent
+This program prints, in our special format, all the third fields that
+contain a positive number in our input.  Therefore, when given:
+
+@example
+ 1.2   3.4    5.6   7.8
+ 9.10 11.12 -13.14 15.16
+17.18 19.20  21.22 23.24
+@end example
+
+@noindent
+this program, using our function to format the results, prints:
+
+@example
+   5.6
+  21.2
+@end example
+
+Here is a rather contrived example of a recursive function.  It prints a
+string backwards:
+
+@example
+function rev (str, len) @{
+    if (len == 0) @{
+        printf "\n"
+        return
+    @}
+    printf "%c", substr(str, len, 1)
+    rev(str, len - 1)
+@}
+@end example
+
+@node Function Caveats, Return Statement, Function Example, User-defined
+@section Calling User-defined Functions
+
+@dfn{Calling a function} means causing the function to run and do its job.
+A function call is an expression, and its value is the value returned by
+the function.
+
+A function call consists of the function name followed by the arguments
+in parentheses.  What you write in the call for the arguments are
+@code{awk} expressions; each time the call is executed, these
+expressions are evaluated, and the values are the actual arguments.  For
+example, here is a call to @code{foo} with three arguments (the first
+being a string concatenation):
+
+@example
+foo(x y, "lose", 4 * z)
+@end example
+
+@quotation
+@strong{Caution:} whitespace characters (spaces and tabs) are not allowed
+between the function name and the open-parenthesis of the argument list.
+If you write whitespace by mistake, @code{awk} might think that you mean
+to concatenate a variable with an expression in parentheses.  However, it
+notices that you used a function name and not a variable name, and reports
+an error.
+@end quotation
+
+@cindex call by value
+When a function is called, it is given a @emph{copy} of the values of
+its arguments.  This is called @dfn{call by value}.  The caller may use
+a variable as the expression for the argument, but the called function
+does not know this: it only knows what value the argument had.  For
+example, if you write this code:
+
+@example
+foo = "bar"
+z = myfunc(foo)
+@end example
+
+@noindent
+then you should not think of the argument to @code{myfunc} as being
+``the variable @code{foo}.''  Instead, think of the argument as the
+string value, @code{"bar"}.
+
+If the function @code{myfunc} alters the values of its local variables,
+this has no effect on any other variables.  In particular, if @code{myfunc}
+does this:
+
+@example
+function myfunc (win) @{
+  print win
+  win = "zzz"
+  print win
+@}
+@end example
+
+@noindent
+to change its first argument variable @code{win}, this @emph{does not}
+change the value of @code{foo} in the caller.  The role of @code{foo} in
+calling @code{myfunc} ended when its value, @code{"bar"}, was computed.
+If @code{win} also exists outside of @code{myfunc}, the function body
+cannot alter this outer value, because it is shadowed during the
+execution of @code{myfunc} and cannot be seen or changed from there.
+
+@cindex call by reference
+However, when arrays are the parameters to functions, they are @emph{not}
+copied.  Instead, the array itself is made available for direct manipulation
+by the function.  This is usually called @dfn{call by reference}.
+Changes made to an array parameter inside the body of a function @emph{are}
+visible outside that function.  
+@ifinfo
+This can be @strong{very} dangerous if you do not watch what you are
+doing.  For example:@refill
+@end ifinfo
+@iftex
+@emph{This can be very dangerous if you do not watch what you are
+doing.}  For example:@refill
+@end iftex
+
+@example
+function changeit (array, ind, nvalue) @{
+     array[ind] = nvalue
+@}
+
+BEGIN @{
+           a[1] = 1 ; a[2] = 2 ; a[3] = 3
+           changeit(a, 2, "two")
+           printf "a[1] = %s, a[2] = %s, a[3] = %s\n", a[1], a[2], a[3]
+      @}
+@end example
+
+@noindent
+prints @samp{a[1] = 1, a[2] = two, a[3] = 3}, because calling
+@code{changeit} stores @code{"two"} in the second element of @code{a}.
+
+@node Return Statement,  , Function Caveats, User-defined
+@section The @code{return} Statement
+@cindex @code{return} statement
+
+The body of a user-defined function can contain a @code{return} statement.
+This statement returns control to the rest of the @code{awk} program.  It
+can also be used to return a value for use in the rest of the @code{awk}
+program.  It looks like this:@refill
+
+@example
+return @var{expression}
+@end example
+
+The @var{expression} part is optional.  If it is omitted, then the returned
+value is undefined and, therefore, unpredictable.
+
+A @code{return} statement with no value expression is assumed at the end of
+every function definition.  So if control reaches the end of the function
+body, then the function returns an unpredictable value.  @code{awk}
+will not warn you if you use the return value of such a function; you will
+simply get unpredictable or unexpected results.
+
+Here is an example of a user-defined function that returns a value
+for the largest number among the elements of an array:@refill
+
+@example
+@group
+function maxelt (vec,   i, ret) @{
+     for (i in vec) @{
+          if (ret == "" || vec[i] > ret)
+               ret = vec[i]
+     @}
+     return ret
+@}
+@end group
+@end example
+
+@noindent
+You call @code{maxelt} with one argument, which is an array name.  The local
+variables @code{i} and @code{ret} are not intended to be arguments;
+while there is nothing to stop you from passing two or three arguments
+to @code{maxelt}, the results would be strange.  The extra space before
+@code{i} in the function parameter list is to indicate that @code{i} and
+@code{ret} are not supposed to be arguments.  This is a convention which
+you should follow when you define functions.
+
+Here is a program that uses our @code{maxelt} function.  It loads an
+array, calls @code{maxelt}, and then reports the maximum number in that
+array:@refill
+
+@example
+@group
+awk '
+function maxelt (vec,   i, ret) @{
+     for (i in vec) @{
+          if (ret == "" || vec[i] > ret)
+               ret = vec[i]
+     @}
+     return ret
+@}
+@end group
+
+@group
+# Load all fields of each record into nums.
+@{
+          for(i = 1; i <= NF; i++)
+               nums[NR, i] = $i
+@}
+
+END @{
+     print maxelt(nums)
+@}'
+@end group
+@end example
+
+Given the following input:
+
+@example
+@group
+ 1 5 23 8 16
+44 3 5 2 8 26
+256 291 1396 2962 100
+-6 467 998 1101
+99385 11 0 225
+@end group
+@end example
+
+@noindent
+our program tells us (predictably) that:
+
+@example
+99385
+@end example
+
+@noindent
+is the largest number in our array.
+
+@node Built-in Variables, Command Line, User-defined, Top
+@chapter Built-in Variables
+@cindex built-in variables
+
+Most @code{awk} variables are available for you to use for your own
+purposes; they never change except when your program assigns values to
+them, and never affect anything except when your program examines them.
+
+A few variables have special built-in meanings.  Some of them @code{awk}
+examines automatically, so that they enable you to tell @code{awk} how
+to do certain things.  Others are set automatically by @code{awk}, so
+that they carry information from the internal workings of @code{awk} to
+your program.
+
+This chapter documents all the built-in variables of @code{gawk}.  Most
+of them are also documented in the chapters where their areas of
+activity are described.
+
+@menu
+* User-modified::               Built-in variables that you change 
+                                to control @code{awk}.
+* Auto-set::                    Built-in variables where @code{awk} 
+                                gives you information.
+@end menu
+
+@node User-modified, Auto-set, Built-in Variables, Built-in Variables
+@section Built-in Variables that Control @code{awk}
+@cindex built-in variables, user modifiable
+
+This is a list of the variables which you can change to control how
+@code{awk} does certain things.
+
+@table @code
+@iftex
+@vindex CONVFMT
+@end iftex
+@item CONVFMT
+This string is used by @code{awk} to control conversion of numbers to
+strings (@pxref{Conversion, ,Conversion of Strings and Numbers}).
+It works by being passed, in effect, as the first argument to the
+@code{sprintf} function.  Its default value is @code{"%.6g"}.
+@code{CONVFMT} was introduced by the @sc{posix} standard.@refill
+
+@iftex
+@vindex FIELDWIDTHS
+@end iftex
+@item FIELDWIDTHS
+This is a space separated list of columns that tells @code{gawk}
+how to manage input with fixed, columnar boundaries.  It is an
+experimental feature that is still evolving.  Assigning to @code{FIELDWIDTHS}
+overrides the use of @code{FS} for field splitting.
+@xref{Constant Size, ,Reading Fixed-width Data}, for more information.@refill
+
+If @code{gawk} is in compatibility mode
+(@pxref{Command Line, ,Invoking @code{awk}}), then @code{FIELDWIDTHS}
+has no special meaning, and field splitting operations are done based
+exclusively on the value of @code{FS}.@refill
+
+@iftex
+@vindex FS
+@end iftex
+@item FS
+@code{FS} is the input field separator
+(@pxref{Field Separators, ,Specifying how Fields are Separated}).
+The value is a single-character string or a multi-character regular
+expression that matches the separations between fields in an input
+record.@refill
+
+The default value is @w{@code{" "}}, a string consisting of a single
+space.  As a special exception, this value actually means that any
+sequence of spaces and tabs is a single separator.  It also causes
+spaces and tabs at the beginning or end of a line to be ignored.
+
+You can set the value of @code{FS} on the command line using the
+@samp{-F} option:
+
+@example
+awk -F, '@var{program}' @var{input-files}
+@end example
+
+If @code{gawk} is using @code{FIELDWIDTHS} for field-splitting,
+assigning a value to @code{FS} will cause @code{gawk} to return to
+the normal, regexp-based, field splitting.
+
+@item IGNORECASE
+@iftex
+@vindex IGNORECASE
+@end iftex
+If @code{IGNORECASE} is nonzero, then @emph{all} regular expression
+matching is done in a case-independent fashion.  In particular, regexp
+matching with @samp{~} and @samp{!~}, and the @code{gsub} @code{index},
+@code{match}, @code{split} and @code{sub} functions all ignore case when
+doing their particular regexp operations.  @strong{Note:} since field
+splitting with the value of the @code{FS} variable is also a regular
+expression operation, that too is done with case ignored.
+@xref{Case-sensitivity, ,Case-sensitivity in Matching}.
+
+If @code{gawk} is in compatibility mode
+(@pxref{Command Line, ,Invoking @code{awk}}), then @code{IGNORECASE} has
+no special meaning, and regexp operations are always case-sensitive.@refill
+
+@item OFMT
+@iftex
+@vindex OFMT
+@end iftex
+This string is used by @code{awk} to control conversion of numbers to
+strings (@pxref{Conversion, ,Conversion of Strings and Numbers}) for
+printing with the @code{print} statement.
+It works by being passed, in effect, as the first argument to the
+@code{sprintf} function.  Its default value is @code{"%.6g"}.
+Earlier versions of @code{awk} also used @code{OFMT} to specify the
+format for converting numbers to strings in general expressions; this
+has been taken over by @code{CONVFMT}.@refill
+
+@item OFS
+@iftex
+@vindex OFS
+@end iftex
+This is the output field separator (@pxref{Output Separators}).  It is
+output between the fields output by a @code{print} statement.  Its
+default value is @w{@code{" "}}, a string consisting of a single space.
+
+@item ORS
+@iftex
+@vindex ORS
+@end iftex
+This is the output record separator.  It is output at the end of every
+@code{print} statement.  Its default value is a string containing a
+single newline character, which could be written as @code{"\n"}.
+(@xref{Output Separators}.)@refill
+
+@item RS
+@iftex
+@vindex RS
+@end iftex
+This is @code{awk}'s input record separator.  Its default value is a string
+containing a single newline character, which means that an input record
+consists of a single line of text.
+(@xref{Records, ,How Input is Split into Records}.)@refill
+
+@item SUBSEP
+@iftex
+@vindex SUBSEP
+@end iftex
+@code{SUBSEP} is the subscript separator.  It has the default value of
+@code{"\034"}, and is used to separate the parts of the name of a
+multi-dimensional array.  Thus, if you access @code{foo[12,3]}, it
+really accesses @code{foo["12\0343"]}
+(@pxref{Multi-dimensional, ,Multi-dimensional Arrays}).@refill
+@end table
+
+@node Auto-set,  , User-modified, Built-in Variables
+@section Built-in Variables that Convey Information
+
+This is a list of the variables that are set automatically by @code{awk}
+on certain occasions so as to provide information to your program.
+
+@table @code
+@item ARGC
+@itemx ARGV
+@iftex
+@vindex ARGC
+@vindex ARGV
+@end iftex
+The command-line arguments available to @code{awk} programs are stored in
+an array called @code{ARGV}.  @code{ARGC} is the number of command-line
+arguments present.  @xref{Command Line, ,Invoking @code{awk}}.
+@code{ARGV} is indexed from zero to @w{@code{ARGC - 1}}.  For example:@refill
+
+@example
+awk 'BEGIN @{
+       for (i = 0; i < ARGC; i++) 
+           print ARGV[i] 
+     @}' inventory-shipped BBS-list
+@end example
+
+@noindent
+In this example, @code{ARGV[0]} contains @code{"awk"}, @code{ARGV[1]}
+contains @code{"inventory-shipped"}, and @code{ARGV[2]} contains
+@code{"BBS-list"}.  The value of @code{ARGC} is 3, one more than the
+index of the last element in @code{ARGV} since the elements are numbered
+from zero.@refill
+
+The names @code{ARGC} and @code{ARGV}, as well the convention of indexing
+the array from 0 to @w{@code{ARGC - 1}}, are derived from the C language's
+method of accessing command line arguments.@refill
+
+Notice that the @code{awk} program is not entered in @code{ARGV}.  The
+other special command line options, with their arguments, are also not
+entered.  But variable assignments on the command line @emph{are}
+treated as arguments, and do show up in the @code{ARGV} array.
+
+Your program can alter @code{ARGC} and the elements of @code{ARGV}.
+Each time @code{awk} reaches the end of an input file, it uses the next
+element of @code{ARGV} as the name of the next input file.  By storing a
+different string there, your program can change which files are read.
+You can use @code{"-"} to represent the standard input.  By storing
+additional elements and incrementing @code{ARGC} you can cause
+additional files to be read.
+
+If you decrease the value of @code{ARGC}, that eliminates input files
+from the end of the list.  By recording the old value of @code{ARGC}
+elsewhere, your program can treat the eliminated arguments as
+something other than file names.
+
+To eliminate a file from the middle of the list, store the null string
+(@code{""}) into @code{ARGV} in place of the file's name.  As a
+special feature, @code{awk} ignores file names that have been
+replaced with the null string.
+
+@ignore
+see getopt.awk in the examples...
+@end ignore
+
+@item ARGIND
+@vindex ARGIND
+The index in @code{ARGV} of the current file being processed.
+Every time @code{gawk} opens a new data file for processing, it sets
+@code{ARGIND} to the index in @code{ARGV} of the file name.  Thus, the
+condition @samp{FILENAME == ARGV[ARGIND]} is always true.
+
+This variable is useful in file processing; it allows you to tell how far
+along you are in the list of data files, and to distinguish between
+multiple successive instances of the same filename on the command line.
+
+While you can change the value of @code{ARGIND} within your @code{awk}
+program, @code{gawk} will automatically set it to a new value when the
+next file is opened.
+
+This variable is a @code{gawk} extension; in other @code{awk} implementations
+it is not special.
+
+@item ENVIRON
+@vindex ENVIRON
+This is an array that contains the values of the environment.  The array
+indices are the environment variable names; the values are the values of
+the particular environment variables.  For example,
+@code{ENVIRON["HOME"]} might be @file{/u/close}.  Changing this array
+does not affect the environment passed on to any programs that
+@code{awk} may spawn via redirection or the @code{system} function.
+(In a future version of @code{gawk}, it may do so.)
+
+Some operating systems may not have environment variables.
+On such systems, the array @code{ENVIRON} is empty.
+
+@item ERRNO
+@iftex
+@vindex ERRNO
+@end iftex
+If a system error occurs either doing a redirection for @code{getline},
+during a read for @code{getline}, or during a @code{close} operation,
+then @code{ERRNO} will contain a string describing the error.
+
+This variable is a @code{gawk} extension; in other @code{awk} implementations
+it is not special.
+
+@item FILENAME
+@iftex
+@vindex FILENAME
+@end iftex
+This is the name of the file that @code{awk} is currently reading.
+If @code{awk} is reading from the standard input (in other words,
+there are no files listed on the command line),
+@code{FILENAME} is set to @code{"-"}.
+@code{FILENAME} is changed each time a new file is read
+(@pxref{Reading Files, ,Reading Input Files}).@refill
+
+@item FNR
+@iftex
+@vindex FNR
+@end iftex
+@code{FNR} is the current record number in the current file.  @code{FNR} is
+incremented each time a new record is read
+(@pxref{Getline, ,Explicit Input with @code{getline}}).  It is reinitialized
+to 0 each time a new input file is started.@refill
+
+@item NF
+@iftex
+@vindex NF
+@end iftex
+@code{NF} is the number of fields in the current input record.
+@code{NF} is set each time a new record is read, when a new field is
+created, or when @code{$0} changes (@pxref{Fields, ,Examining Fields}).@refill
+
+@item NR
+@iftex
+@vindex NR
+@end iftex
+This is the number of input records @code{awk} has processed since
+the beginning of the program's execution.
+(@pxref{Records, ,How Input is Split into Records}).
+@code{NR} is set each time a new record is read.@refill
+
+@item RLENGTH
+@iftex
+@vindex RLENGTH
+@end iftex
+@code{RLENGTH} is the length of the substring matched by the
+@code{match} function
+(@pxref{String Functions, ,Built-in Functions for String Manipulation}).
+@code{RLENGTH} is set by invoking the @code{match} function.  Its value
+is the length of the matched string, or @minus{}1 if no match was found.@refill
+
+@item RSTART
+@iftex
+@vindex RSTART
+@end iftex
+@code{RSTART} is the start-index in characters of the substring matched by the
+@code{match} function
+(@pxref{String Functions, ,Built-in Functions for String Manipulation}).
+@code{RSTART} is set by invoking the @code{match} function.  Its value
+is the position of the string where the matched substring starts, or 0
+if no match was found.@refill
+@end table
+
+@node Command Line, Language History, Built-in Variables, Top
+@c node-name, next, previous, up
+@chapter Invoking @code{awk}
+@cindex command line
+@cindex invocation of @code{gawk}
+@cindex arguments, command line
+@cindex options, command line
+@cindex long options
+@cindex options, long
+
+There are two ways to run @code{awk}: with an explicit program, or with
+one or more program files.  Here are templates for both of them; items
+enclosed in @samp{@r{[}@dots{}@r{]}} in these templates are optional.
+
+Besides traditional one-letter @sc{posix}-style options, @code{gawk} also
+supports GNU long named options.
+
+@example
+awk @r{[@var{POSIX or GNU style options}]} -f progfile @r{[@code{--}]} @var{file} @dots{}
+awk @r{[@var{POSIX or GNU style options}]} @r{[@code{--}]} '@var{program}' @var{file} @dots{}
+@end example
+
+@menu
+* Options::                     Command line options and their meanings.
+* Other Arguments::             Input file names and variable assignments.
+* AWKPATH Variable::            Searching directories for @code{awk} programs.
+* Obsolete::                    Obsolete Options and/or features.
+* Undocumented::                Undocumented Options and Features.
+@end menu
+
+@node Options, Other Arguments, Command Line, Command Line
+@section Command Line Options
+
+Options begin with a minus sign, and consist of a single character.
+GNU style long named options consist of two minus signs and
+a keyword that can be abbreviated if the abbreviation allows the option
+to be uniquely identified.  If the option takes an argument, then the
+keyword is immediately followed by an equals sign (@samp{=}) and the
+argument's value.  For brevity, the discussion below only refers to the
+traditional short options; however the long and short options are
+interchangeable in all contexts.
+
+Each long named option for @code{gawk} has a corresponding
+@sc{posix}-style option.  The options and their meanings are as follows:
+
+@table @code
+@item -F @var{fs}
+@itemx --field-separator=@var{fs}
+@iftex
+@cindex @code{-F} option
+@end iftex
+@cindex @code{--field-separator} option
+Sets the @code{FS} variable to @var{fs}
+(@pxref{Field Separators, ,Specifying how Fields are Separated}).@refill
+
+@item -f @var{source-file}
+@itemx --file=@var{source-file}
+@iftex
+@cindex @code{-f} option
+@end iftex
+@cindex @code{--file} option
+Indicates that the @code{awk} program is to be found in @var{source-file}
+instead of in the first non-option argument.
+
+@item -v @var{var}=@var{val}
+@itemx --assign=@var{var}=@var{val}
+@cindex @samp{-v} option
+@cindex @code{--assign} option
+Sets the variable @var{var} to the value @var{val} @emph{before}
+execution of the program begins.  Such variable values are available
+inside the @code{BEGIN} rule (see below for a fuller explanation).
+
+The @samp{-v} option can only set one variable, but you can use
+it more than once, setting another variable each time, like this:
+@samp{@w{-v foo=1} @w{-v bar=2}}.
+
+@item -W @var{gawk-opt}
+@cindex @samp{-W} option
+Following the @sc{posix} standard, options that are implementation
+specific are supplied as arguments to the @samp{-W} option.  With @code{gawk},
+these arguments may be separated by commas, or quoted and separated by
+whitespace.  Case is ignored when processing these options.  These options
+also have corresponding GNU style long named options.  The following
+@code{gawk}-specific options are available:
+
+@table @code
+@item -W compat
+@itemx --compat
+@cindex @code{--compat} option
+Specifies @dfn{compatibility mode}, in which the GNU extensions in
+@code{gawk} are disabled, so that @code{gawk} behaves just like Unix
+@code{awk}.
+@xref{POSIX/GNU, ,Extensions in @code{gawk} not in POSIX @code{awk}},
+which summarizes the extensions.  Also see
+@ref{Compatibility Mode, ,Downward Compatibility and Debugging}.@refill
+
+@item -W copyleft
+@itemx -W copyright
+@itemx --copyleft
+@itemx --copyright
+@cindex @code{--copyleft} option
+@cindex @code{--copyright} option
+Print the short version of the General Public License.
+This option may disappear in a future version of @code{gawk}.  
+
+@item -W help
+@itemx -W usage
+@itemx --help
+@itemx --usage
+@cindex @code{--help} option
+@cindex @code{--usage} option
+Print a ``usage'' message summarizing the short and long style options
+that @code{gawk} accepts, and then exit.
+
+@item -W lint
+@itemx --lint
+@cindex @code{--lint} option
+Provide warnings about constructs that are dubious or non-portable to
+other @code{awk} implementations.
+Some warnings are issued when @code{gawk} first reads your program.  Others
+are issued at run-time, as your program executes.
+
+@item -W posix
+@itemx --posix
+@cindex @code{--posix} option
+Operate in strict @sc{posix} mode.  This disables all @code{gawk}
+extensions (just like @code{-W compat}), and adds the following additional
+restrictions:
+
+@itemize @bullet{}
+@item
+@code{\x} escape sequences are not recognized
+(@pxref{Constants, ,Constant Expressions}).@refill
+
+@item
+The synonym @code{func} for the keyword @code{function} is not
+recognized (@pxref{Definition Syntax, ,Syntax of Function Definitions}).
+
+@item
+The operators @samp{**} and @samp{**=} cannot be used in
+place of @samp{^} and @samp{^=} (@pxref{Arithmetic Ops, ,Arithmetic Operators},
+and also @pxref{Assignment Ops, ,Assignment Expressions}).@refill
+
+@item
+Specifying @samp{-Ft} on the command line does not set the value
+of @code{FS} to be a single tab character
+(@pxref{Field Separators, ,Specifying how Fields are Separated}).@refill
+@end itemize
+
+Although you can supply both @samp{-W compat} and @samp{-W posix} on the
+command line, @samp{-W posix} will take precedence.
+
+@item -W source=@var{program-text}
+@itemx --source=@var{program-text}
+@cindex @code{--source} option
+Program source code is taken from the @var{program-text}.  This option
+allows you to mix @code{awk} source code in files with program source
+code that you would enter on the command line. This is particularly useful
+when you have library functions that you wish to use from your command line
+programs (@pxref{AWKPATH Variable, ,The @code{AWKPATH} Environment Variable}).
+
+@item -W version
+@itemx --version
+@cindex @code{--version} option
+Prints version information for this particular copy of @code{gawk}.
+This is so you can determine if your copy of @code{gawk} is up to date
+with respect to whatever the Free Software Foundation is currently
+distributing.  This option may disappear in a future version of @code{gawk}.
+@end table
+
+@item --
+Signals the end of the command line options.  The following arguments
+are not treated as options even if they begin with @samp{-}.  This
+interpretation of @samp{--} follows the @sc{posix} argument parsing
+conventions.
+
+This is useful if you have file names that start with @samp{-},
+or in shell scripts, if you have file names that will be specified
+by the user which could start with @samp{-}.
+@end table
+
+Any other options are flagged as invalid with a warning message, but
+are otherwise ignored.
+
+In compatibility mode, as a special case, if the value of @var{fs} supplied
+to the @samp{-F} option is @samp{t}, then @code{FS} is set to the tab
+character (@code{"\t"}).  This is only true for @samp{-W compat}, and not
+for @samp{-W posix}
+(@pxref{Field Separators, ,Specifying how Fields are Separated}).@refill
+
+If the @samp{-f} option is @emph{not} used, then the first non-option
+command line argument is expected to be the program text.
+
+The @samp{-f} option may be used more than once on the command line.
+If it is, @code{awk} reads its program source from all of the named files, as
+if they had been concatenated together into one big file.  This is
+useful for creating libraries of @code{awk} functions.  Useful functions
+can be written once, and then retrieved from a standard place, instead
+of having to be included into each individual program.  You can still
+type in a program at the terminal and use library functions, by specifying
+@samp{-f /dev/tty}.  @code{awk} will read a file from the terminal
+to use as part of the @code{awk} program.  After typing your program,
+type @kbd{Control-d} (the end-of-file character) to terminate it.
+(You may also use @samp{-f -} to read program source from the standard
+input, but then you will not be able to also use the standard input as a
+source of data.)
+
+Because it is clumsy using the standard @code{awk} mechanisms to mix source
+file and command line @code{awk} programs, @code{gawk} provides the
+@samp{--source} option.  This does not require you to pre-empt the standard
+input for your source code, and allows you to easily mix command line
+and library source code
+(@pxref{AWKPATH Variable, ,The @code{AWKPATH} Environment Variable}).
+
+If no @samp{-f} or @samp{--source} option is specified, then @code{gawk}
+will use the first non-option command line argument as the text of the
+program source code.
+
+@node Other Arguments, AWKPATH Variable, Options, Command Line
+@section Other Command Line Arguments
+
+Any additional arguments on the command line are normally treated as
+input files to be processed in the order specified.  However, an
+argument that has the form @code{@var{var}=@var{value}}, means to assign
+the value @var{value} to the variable @var{var}---it does not specify a
+file at all.
+
+@vindex ARGV
+All these arguments are made available to your @code{awk} program in the
+@code{ARGV} array (@pxref{Built-in Variables}).  Command line options
+and the program text (if present) are omitted from the @code{ARGV}
+array.  All other arguments, including variable assignments, are
+included.
+
+The distinction between file name arguments and variable-assignment
+arguments is made when @code{awk} is about to open the next input file.
+At that point in execution, it checks the ``file name'' to see whether
+it is really a variable assignment; if so, @code{awk} sets the variable
+instead of reading a file.
+
+Therefore, the variables actually receive the specified values after all
+previously specified files have been read.  In particular, the values of
+variables assigned in this fashion are @emph{not} available inside a
+@code{BEGIN} rule
+(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}),
+since such rules are run before @code{awk} begins scanning the argument list.
+The values given on the command line are processed for escape sequences
+(@pxref{Constants, ,Constant Expressions}).@refill
+
+In some earlier implementations of @code{awk}, when a variable assignment
+occurred before any file names, the assignment would happen @emph{before}
+the @code{BEGIN} rule was executed.  Some applications came to depend
+upon this ``feature.''  When @code{awk} was changed to be more consistent,
+the @samp{-v} option was added to accommodate applications that depended
+upon this old behavior.
+
+The variable assignment feature is most useful for assigning to variables
+such as @code{RS}, @code{OFS}, and @code{ORS}, which control input and
+output formats, before scanning the data files.  It is also useful for
+controlling state if multiple passes are needed over a data file.  For
+example:@refill
+
+@cindex multiple passes over data
+@cindex passes, multiple
+@smallexample
+awk 'pass == 1  @{ @var{pass 1 stuff} @}
+     pass == 2  @{ @var{pass 2 stuff} @}' pass=1 datafile pass=2 datafile
+@end smallexample
+
+Given the variable assignment feature, the @samp{-F} option is not
+strictly necessary.  It remains for historical compatibility.
+
+@node AWKPATH Variable, Obsolete, Other Arguments, Command Line
+@section The @code{AWKPATH} Environment Variable
+@cindex @code{AWKPATH} environment variable
+@cindex search path
+@cindex directory search
+@cindex path, search
+@iftex
+@cindex differences between @code{gawk} and @code{awk}
+@end iftex
+
+The previous section described how @code{awk} program files can be named
+on the command line with the @samp{-f} option.  In some @code{awk}
+implementations, you must supply a precise path name for each program
+file, unless the file is in the current directory.
+
+But in @code{gawk}, if the file name supplied in the @samp{-f} option
+does not contain a @samp{/}, then @code{gawk} searches a list of
+directories (called the @dfn{search path}), one by one, looking for a
+file with the specified name.
+
+The search path is actually a string consisting of directory names
+separated by colons.  @code{gawk} gets its search path from the
+@code{AWKPATH} environment variable.  If that variable does not exist,
+@code{gawk} uses the default path, which is
+@samp{.:/usr/lib/awk:/usr/local/lib/awk}.  (Programs written by
+system administrators should use an @code{AWKPATH} variable that
+does not include the current directory, @samp{.}.)@refill
+
+The search path feature is particularly useful for building up libraries
+of useful @code{awk} functions.  The library files can be placed in a
+standard directory that is in the default path, and then specified on
+the command line with a short file name.  Otherwise, the full file name
+would have to be typed for each file.
+
+By combining the @samp{--source} and @samp{-f} options, your command line
+@code{awk} programs can use facilities in @code{awk} library files.
+
+Path searching is not done if @code{gawk} is in compatibility mode.
+This is true for both @samp{-W compat} and @samp{-W posix}.
+@xref{Options, ,Command Line Options}.
+
+@strong{Note:} if you want files in the current directory to be found,
+you must include the current directory in the path, either by writing
+@file{.} as an entry in the path, or by writing a null entry in the
+path.  (A null entry is indicated by starting or ending the path with a
+colon, or by placing two colons next to each other (@samp{::}).)  If the
+current directory is not included in the path, then files cannot be
+found in the current directory.  This path search mechanism is identical
+to the shell's.
+@c someday, @cite{The Bourne Again Shell}....
+
+@node Obsolete, Undocumented, AWKPATH Variable, Command Line
+@section Obsolete Options and/or Features
+
+@cindex deprecated options
+@cindex obsolete options
+@cindex deprecated features
+@cindex obsolete features
+This section describes features and/or command line options from the
+previous release of @code{gawk} that are either not available in the
+current version, or that are still supported but deprecated (meaning that
+they will @emph{not} be in the next release).
+
+@c update this section for each release!
+
+For version 2.15 of @code{gawk}, the following command line options
+from version 2.11.1 are no longer recognized.
+
+@table @samp
+@ignore
+@item -nostalgia
+Use @samp{-W nostalgia} instead.
+@end ignore
+
+@item -c
+Use @samp{-W compat} instead.
+
+@item -V
+Use @samp{-W version} instead.
+
+@item -C
+Use @samp{-W copyright} instead.
+
+@item -a
+@itemx -e
+These options produce an ``unrecognized option'' error message but have
+no effect on the execution of @code{gawk}.  The @sc{posix} standard now
+specifies traditional @code{awk} regular expressions for the @code{awk} utility.
+@end table
+
+The public-domain version of @code{strftime} that is distributed with
+@code{gawk} changed for the 2.14 release.  The @samp{%V} conversion specifier
+that used to generate the date in VMS format was changed to @samp{%v}.
+This is because the @sc{posix} standard for the @code{date} utility now
+specifies a @samp{%V} conversion specifier.
+@xref{Time Functions, ,Functions for Dealing with Time Stamps}, for details.
+
+@node Undocumented,  , Obsolete, Command Line
+@section Undocumented Options and Features
+
+This section intentionally left blank.
+
+@c Read The Source, Luke!
+
+@ignore
+@c If these came out in the Info file or TeX manual, then they wouldn't
+@c be undocumented, would they?
+
+@code{gawk} has one undocumented option:
+
+@table @samp
+@item -W nostalgia
+Print the message @code{"awk: bailing out near line 1"} and dump core.
+This option was inspired by the common behavior of very early versions of
+Unix @code{awk}, and by a t--shirt.
+@end table
+
+Early versions of @code{awk} used to not require any separator (either
+a newline or @samp{;}) between the rules in @code{awk} programs.  Thus,
+it was common to see one-line programs like:
+
+@example
+awk '@{ sum += $1 @} END @{ print sum @}'
+@end example
+
+@code{gawk} actually supports this, but it is purposely undocumented
+since it is considered bad style.  The correct way to write such a program
+is either
+
+@example
+awk '@{ sum += $1 @} ; END @{ print sum @}'
+@end example
+
+@noindent
+or
+
+@example
+awk '@{ sum += $1 @}
+     END @{ print sum @}' data
+@end example
+
+@noindent
+@xref{Statements/Lines, ,@code{awk} Statements versus Lines}, for a fuller
+explanation.@refill
+
+As an accident of the implementation of the original Unix @code{awk}, if
+a built-in function used @code{$0} as its default argument, it was possible
+to call that function without the parentheses.  In particular, it was
+common practice to use the @code{length} function in this fashion.
+For example, the pipeline:
+
+@example
+echo abcdef | awk '@{ print length @}'
+@end example
+
+@noindent
+would print @samp{6}.
+
+For backwards compatibility with old programs, @code{gawk} supports
+this usage, but only for the @code{length} function.  New programs should
+@emph{not} call the @code{length} function this way.  In particular,
+this usage will not be portable to other @sc{posix} compliant versions
+of @code{awk}.  It is also poor style.
+
+@end ignore
+
+@node Language History, Installation, Command Line, Top
+@chapter The Evolution of the @code{awk} Language
+
+This manual describes the GNU implementation of @code{awk}, which is patterned
+after the @sc{posix} specification.  Many @code{awk} users are only familiar
+with the original @code{awk} implementation in Version 7 Unix, which is also
+the basis for the version in Berkeley Unix (through 4.3--Reno).  This chapter
+briefly describes the evolution of the @code{awk} language.
+
+@menu
+* V7/S5R3.1::                   The major changes between V7 and 
+                                System V Release 3.1.
+* S5R4::                        Minor changes between System V 
+                                Releases 3.1 and 4.
+* POSIX::                       New features from the @sc{posix} standard.
+* POSIX/GNU::                   The extensions in @code{gawk} 
+                                not in @sc{posix} @code{awk}.
+@end menu
+
+@node V7/S5R3.1, S5R4, Language History, Language History
+@section Major Changes between V7 and S5R3.1
+
+The @code{awk} language evolved considerably between the release of
+Version 7 Unix (1978) and the new version first made widely available in
+System V Release 3.1 (1987).  This section summarizes the changes, with
+cross-references to further details.
+
+@itemize @bullet
+@item
+The requirement for @samp{;} to separate rules on a line
+(@pxref{Statements/Lines, ,@code{awk} Statements versus Lines}).
+
+@item
+User-defined functions, and the @code{return} statement
+(@pxref{User-defined, ,User-defined Functions}).
+
+@item
+The @code{delete} statement (@pxref{Delete, ,The @code{delete} Statement}).
+
+@item
+The @code{do}-@code{while} statement
+(@pxref{Do Statement, ,The @code{do}-@code{while} Statement}).@refill
+
+@item
+The built-in functions @code{atan2}, @code{cos}, @code{sin}, @code{rand} and
+@code{srand} (@pxref{Numeric Functions, ,Numeric Built-in Functions}).
+
+@item
+The built-in functions @code{gsub}, @code{sub}, and @code{match}
+(@pxref{String Functions, ,Built-in Functions for String Manipulation}).
+
+@item
+The built-in functions @code{close}, which closes an open file, and
+@code{system}, which allows the user to execute operating system
+commands (@pxref{I/O Functions, ,Built-in Functions for Input/Output}).@refill
+@c Does the above verbiage prevents an overfull hbox?  --mew, rjc 24jan1992
+
+@item
+The @code{ARGC}, @code{ARGV}, @code{FNR}, @code{RLENGTH}, @code{RSTART},
+and @code{SUBSEP} built-in variables (@pxref{Built-in Variables}).
+
+@item
+The conditional expression using the operators @samp{?} and @samp{:}
+(@pxref{Conditional Exp, ,Conditional Expressions}).@refill
+
+@item
+The exponentiation operator @samp{^}
+(@pxref{Arithmetic Ops, ,Arithmetic Operators}) and its assignment operator
+form @samp{^=} (@pxref{Assignment Ops, ,Assignment Expressions}).@refill
+
+@item
+C-compatible operator precedence, which breaks some old @code{awk}
+programs (@pxref{Precedence, ,Operator Precedence (How Operators Nest)}).
+
+@item
+Regexps as the value of @code{FS}
+(@pxref{Field Separators, ,Specifying how Fields are Separated}), and as the
+third argument to the @code{split} function
+(@pxref{String Functions, ,Built-in Functions for String Manipulation}).@refill
+
+@item
+Dynamic regexps as operands of the @samp{~} and @samp{!~} operators
+(@pxref{Regexp Usage, ,How to Use Regular Expressions}).
+
+@item
+Escape sequences (@pxref{Constants, ,Constant Expressions}) in regexps.@refill
+
+@item
+The escape sequences @samp{\b}, @samp{\f}, and @samp{\r}
+(@pxref{Constants, ,Constant Expressions}).
+
+@item
+Redirection of input for the @code{getline} function
+(@pxref{Getline, ,Explicit Input with @code{getline}}).@refill
+
+@item
+Multiple @code{BEGIN} and @code{END} rules
+(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}).@refill
+
+@item
+Simulated multi-dimensional arrays
+(@pxref{Multi-dimensional, ,Multi-dimensional Arrays}).@refill
+@end itemize
+
+@node S5R4, POSIX, V7/S5R3.1, Language History
+@section Changes between S5R3.1 and S5R4
+
+The System V Release 4 version of Unix @code{awk} added these features
+(some of which originated in @code{gawk}):
+
+@itemize @bullet
+@item
+The @code{ENVIRON} variable (@pxref{Built-in Variables}).
+
+@item
+Multiple @samp{-f} options on the command line
+(@pxref{Command Line, ,Invoking @code{awk}}).@refill
+
+@item
+The @samp{-v} option for assigning variables before program execution begins
+(@pxref{Command Line, ,Invoking @code{awk}}).@refill
+
+@item
+The @samp{--} option for terminating command line options.
+
+@item
+The @samp{\a}, @samp{\v}, and @samp{\x} escape sequences
+(@pxref{Constants, ,Constant Expressions}).@refill
+
+@item
+A defined return value for the @code{srand} built-in function
+(@pxref{Numeric Functions, ,Numeric Built-in Functions}).
+
+@item
+The @code{toupper} and @code{tolower} built-in string functions
+for case translation
+(@pxref{String Functions, ,Built-in Functions for String Manipulation}).@refill
+
+@item
+A cleaner specification for the @samp{%c} format-control letter in the
+@code{printf} function
+(@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing}).@refill
+
+@item
+The ability to dynamically pass the field width and precision (@code{"%*.*d"})
+in the argument list of the @code{printf} function
+(@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing}).@refill
+
+@item
+The use of constant regexps such as @code{/foo/} as expressions, where
+they are equivalent to use of the matching operator, as in @code{$0 ~
+/foo/} (@pxref{Constants, ,Constant Expressions}).
+@end itemize
+
+@node POSIX, POSIX/GNU, S5R4, Language History
+@section Changes between S5R4 and POSIX @code{awk}
+
+The @sc{posix} Command Language and Utilities standard for @code{awk}
+introduced the following changes into the language:
+
+@itemize @bullet{}
+@item
+The use of @samp{-W} for implementation-specific options.
+
+@item
+The use of @code{CONVFMT} for controlling the conversion of numbers
+to strings (@pxref{Conversion, ,Conversion of Strings and Numbers}).
+
+@item
+The concept of a numeric string, and tighter comparison rules to go
+with it (@pxref{Comparison Ops, ,Comparison Expressions}).
+
+@item
+More complete documentation of many of the previously undocumented
+features of the language.
+@end itemize
+
+@node POSIX/GNU,  , POSIX, Language History
+@section Extensions in @code{gawk} not in POSIX @code{awk}
+
+The GNU implementation, @code{gawk}, adds these features:
+
+@itemize @bullet
+@item
+The @code{AWKPATH} environment variable for specifying a path search for
+the @samp{-f} command line option
+(@pxref{Command Line, ,Invoking @code{awk}}).@refill
+
+@item
+The various @code{gawk} specific features available via the @samp{-W}
+command line option (@pxref{Command Line, ,Invoking @code{awk}}).
+
+@item
+The @code{ARGIND} variable, that tracks the movement of @code{FILENAME}
+through @code{ARGV}.  (@pxref{Built-in Variables}).
+
+@item
+The @code{ERRNO} variable, that contains the system error message when
+@code{getline} returns @minus{}1, or when @code{close} fails.
+(@pxref{Built-in Variables}).
+
+@item
+The @code{IGNORECASE} variable and its effects
+(@pxref{Case-sensitivity, ,Case-sensitivity in Matching}).@refill
+
+@item
+The @code{FIELDWIDTHS} variable and its effects
+(@pxref{Constant Size, ,Reading Fixed-width Data}).@refill
+
+@item
+The @code{next file} statement for skipping to the next data file
+(@pxref{Next File Statement, ,The @code{next file} Statement}).@refill
+
+@item
+The @code{systime} and @code{strftime} built-in functions for obtaining
+and printing time stamps
+(@pxref{Time Functions, ,Functions for Dealing with Time Stamps}).@refill
+
+@item
+The @file{/dev/stdin}, @file{/dev/stdout}, @file{/dev/stderr}, and
+@file{/dev/fd/@var{n}} file name interpretation
+(@pxref{Special Files, ,Standard I/O Streams}).@refill
+
+@item
+The @samp{-W compat} option to turn off these extensions
+(@pxref{Command Line, ,Invoking @code{awk}}).@refill
+
+@item
+The @samp{-W posix} option for full @sc{posix} compliance
+(@pxref{Command Line, ,Invoking @code{awk}}).@refill
+
+@end itemize
+
+@node Installation, Gawk Summary, Language History, Top
+@chapter Installing @code{gawk}
+
+This chapter provides instructions for installing @code{gawk} on the
+various platforms that are supported by the developers.  The primary
+developers support Unix (and one day, GNU), while the other ports were
+contributed.  The file @file{ACKNOWLEDGMENT} in the @code{gawk}
+distribution lists the electronic mail addresses of the people who did
+the respective ports.@refill
+
+@menu
+* Gawk Distribution::           What is in the @code{gawk} distribution.
+* Unix Installation::           Installing @code{gawk} under various versions
+                                of Unix.
+* VMS Installation::            Installing @code{gawk} on VMS.
+* MS-DOS Installation::         Installing @code{gawk} on MS-DOS.
+* Atari Installation::          Installing @code{gawk} on the Atari ST.
+@end menu
+
+@node Gawk Distribution, Unix Installation, Installation, Installation
+@section The @code{gawk} Distribution
+
+This section first describes how to get and extract the @code{gawk}
+distribution, and then discusses what is in the various files and
+subdirectories.
+
+@menu
+* Extracting::                  How to get and extract the distribution.
+* Distribution contents::       What is in the distribution.
+@end menu
+
+@node Extracting, Distribution contents, Gawk Distribution, Gawk Distribution
+@subsection Getting the @code{gawk} Distribution
+
+@cindex getting gawk
+@cindex anonymous ftp
+@cindex anonymous uucp
+@cindex ftp, anonymous
+@cindex uucp, anonymous
+@code{gawk} is distributed as a @code{tar} file compressed with the
+GNU Zip program, @code{gzip}.  You can
+get it via anonymous @code{ftp} to the Internet host @code{prep.ai.mit.edu}.
+Like all GNU software, it will be archived at other well known systems,
+from which it will be possible to use some sort of anonymous @code{uucp} to
+obtain the distribution as well.
+You can also order @code{gawk} on tape or CD-ROM directly from the
+Free Software Foundation.  (The address is on the copyright page.)
+Doing so directly contributes to the support of the foundation and to
+the production of more free software.
+
+Once you have the distribution (for example,
+@file{gawk-2.15.0.tar.z}), first use @code{gzip} to expand the
+file, and then use @code{tar} to extract it.  You can use the following
+pipeline to produce the @code{gawk} distribution:
+
+@example
+# Under System V, add 'o' to the tar flags
+gzip -d -c gawk-2.15.0.tar.z | tar -xvpf -
+@end example
+
+@noindent
+This will create a directory named @file{gawk-2.15} in the current
+directory.
+
+The distribution file name is of the form @file{gawk-2.15.@var{n}.tar.Z}.
+The @var{n} represents a @dfn{patchlevel}, meaning that minor bugs have
+been fixed in the major release.  The current patchlevel is 0, but when
+retrieving distributions, you should get the version with the highest
+patchlevel.@refill
+
+If you are not on a Unix system, you will need to make other arrangements
+for getting and extracting the @code{gawk} distribution.  You should consult
+a local expert.
+
+@node Distribution contents,  , Extracting, Gawk Distribution
+@subsection Contents of the @code{gawk} Distribution
+
+@code{gawk} has a number of C source files, documentation files,
+subdirectories and files related to the configuration process
+(@pxref{Unix Installation, ,Compiling and Installing @code{gawk} on Unix}),
+and several subdirectories related to different, non-Unix,
+operating systems.@refill
+
+@table @asis
+@item various @samp{.c}, @samp{.y}, and @samp{.h} files 
+
+The C and YACC source files are the actual @code{gawk} source code.
+@end table
+
+@table @file
+@item README
+@itemx README.VMS
+@itemx README.dos
+@itemx README.rs6000
+@itemx README.ultrix
+Descriptive files: @file{README} for @code{gawk} under Unix, and the
+rest for the various hardware and software combinations.
+
+@item PORTS
+A list of systems to which @code{gawk} has been ported, and which
+have successfully run the test suite.
+
+@item ACKNOWLEDGMENT
+A list of the people who contributed major parts of the code or documentation.
+
+@item NEWS
+A list of changes to @code{gawk} since the last release or patch.
+
+@item COPYING
+The GNU General Public License.
+
+@item FUTURES
+A brief list of features and/or changes being contemplated for future
+releases, with some indication of the time frame for the feature, based
+on its difficulty.
+
+@item LIMITATIONS
+A list of those factors that limit @code{gawk}'s performance.
+Most of these depend on the hardware or operating system software, and
+are not limits in @code{gawk} itself.@refill
+
+@item PROBLEMS
+A file describing known problems with the current release.
+
+@item gawk.1
+The @code{troff} source for a manual page describing @code{gawk}.
+
+@item gawk.texinfo
+@ifinfo
+The @code{texinfo} source file for this Info file.
+It should be processed with @TeX{} to produce a printed manual, and
+with @code{makeinfo} to produce the Info file.@refill
+@end ifinfo
+@iftex
+The @code{texinfo} source file for this manual.
+It should be processed with @TeX{} to produce a printed manual, and
+with @code{makeinfo} to produce the Info file.@refill
+@end iftex
+
+@item Makefile.in
+@itemx config
+@itemx config.in
+@itemx configure
+@itemx missing
+@itemx mungeconf
+These files and subdirectories are used when configuring @code{gawk}
+for various Unix systems.  They are explained in detail in
+@ref{Unix Installation, ,Compiling and Installing @code{gawk} on Unix}.@refill
+
+@item atari
+Files needed for building @code{gawk} on an Atari ST.
+@xref{Atari Installation, ,Installing @code{gawk} on the Atari ST}, for details.
+
+@item pc
+Files needed for building @code{gawk} under MS-DOS.
+@xref{MS-DOS Installation, ,Installing @code{gawk} on MS-DOS}, for details.
+
+@item vms
+Files needed for building @code{gawk} under VMS.
+@xref{VMS Installation, ,Compiling Installing and Running @code{gawk} on VMS}, for details.
+
+@item test
+Many interesting @code{awk} programs, provided as a test suite for
+@code{gawk}.  You can use @samp{make test} from the top level @code{gawk}
+directory to run your version of @code{gawk} against the test suite.
+@c There are many programs here that are useful in their own right.
+If @code{gawk} successfully passes @samp{make test} then you can
+be confident of a successful port.@refill
+@end table
+
+@node Unix Installation, VMS Installation, Gawk Distribution, Installation
+@section Compiling and Installing @code{gawk} on Unix
+
+Often, you can compile and install @code{gawk} by typing only two
+commands.  However, if you do not use a supported system, you may need
+to configure @code{gawk} for your system yourself.
+
+@menu
+* Quick Installation::          Compiling @code{gawk} on a 
+                                supported Unix version.
+* Configuration Philosophy::    How it's all supposed to work.
+* New Configurations::          What to do if there is no supplied 
+                                configuration for your system.
+@end menu
+
+@node Quick Installation, Configuration Philosophy, Unix Installation, Unix Installation
+@subsection Compiling @code{gawk} for a Supported Unix Version
+
+@cindex installation, unix
+After you have extracted the @code{gawk} distribution, @code{cd}
+to @file{gawk-2.15}.  Look in the @file{config} subdirectory for a
+file that matches your hardware/software combination.  In general,
+only the software is relevant; for example @code{sunos41} is used
+for SunOS 4.1, on both Sun 3 and Sun 4 hardware.@refill
+
+If you find such a file, run the command:
+
+@example
+# assume you have SunOS 4.1
+./configure sunos41
+@end example
+
+This produces a @file{Makefile} and @file{config.h} tailored to your
+system.  You may wish to edit the @file{Makefile} to use a different
+C compiler, such as @code{gcc}, the GNU C compiler, if you have it.
+You may also wish to change the @code{CFLAGS} variable, which controls
+the command line options that are passed to the C compiler (such as
+optimization levels, or compiling for debugging).@refill
+
+After you have configured @file{Makefile} and @file{config.h}, type:
+
+@example
+make
+@end example
+
+@noindent
+and shortly thereafter, you should have an executable version of @code{gawk}.
+That's all there is to it!
+
+@node Configuration Philosophy, New Configurations, Quick Installation, Unix Installation
+@subsection The Configuration Process
+
+(This section is of interest only if you know something about using the
+C language and the Unix operating system.)
+
+The source code for @code{gawk} generally attempts to adhere to industry
+standards wherever possible.  This means that @code{gawk} uses library
+routines that are specified by the @sc{ansi} C standard and by the @sc{posix}
+operating system interface standard.  When using an @sc{ansi} C compiler,
+function prototypes are provided to help improve the compile-time checking.
+
+Many older Unix systems do not support all of either the @sc{ansi} or the
+@sc{posix} standards.  The @file{missing} subdirectory in the @code{gawk}
+distribution contains replacement versions of those subroutines that are
+most likely to be missing.
+
+The @file{config.h} file that is created by the @code{configure} program
+contains definitions that describe features of the particular operating
+system where you are attempting to compile @code{gawk}.  For the most
+part, it lists which standard subroutines are @emph{not} available.
+For example, if your system lacks the @samp{getopt} routine, then
+@samp{GETOPT_MISSING} would be defined.
+
+@file{config.h} also defines constants that describe facts about your
+variant of Unix.  For example, there may not be an @samp{st_blksize}
+element in the @code{stat} structure.  In this case @samp{BLKSIZE_MISSING}
+would be defined.
+
+Based on the list in @file{config.h} of standard subroutines that are
+missing, @file{missing.c} will do a @samp{#include} of the appropriate
+file(s) from the @file{missing} subdirectory.@refill
+
+Conditionally compiled code in the other source files relies on the
+other definitions in the @file{config.h} file.
+
+Besides creating @file{config.h}, @code{configure} produces a @file{Makefile}
+from @file{Makefile.in}.  There are a number of lines in @file{Makefile.in}
+that are system or feature specific.  For example, there is line that begins
+with @samp{##MAKE_ALLOCA_C##}.  This is normally a comment line, since
+it starts with @samp{#}.  If a configuration file has @samp{MAKE_ALLOCA_C}
+in it, then @code{configure} will delete the @samp{##MAKE_ALLOCA_C##}
+from the beginning of the line.  This will enable the rules in the
+@file{Makefile} that use a C version of @samp{alloca}.  There are several
+similar features that work in this fashion.@refill
+
+@node New Configurations,  , Configuration Philosophy, Unix Installation
+@subsection Configuring @code{gawk} for a New System
+
+(This section is of interest only if you know something about using the
+C language and the Unix operating system, and if you have to install
+@code{gawk} on a system that is not supported by the @code{gawk} distribution.
+If you are a C or Unix novice, get help from a local expert.)
+
+If you need to configure @code{gawk} for a Unix system that is not
+supported in the distribution, first see
+@ref{Configuration Philosophy, ,The Configuration Process}.
+Then, copy @file{config.in} to @file{config.h}, and copy
+@file{Makefile.in} to @file{Makefile}.@refill
+
+Next, edit both files.  Both files are liberally commented, and the
+necessary changes should be straightforward.
+
+While editing @file{config.h}, you need to determine what library
+routines you do or do not have by consulting your system documentation, or
+by perusing your actual libraries using the @code{ar} or @code{nm} utilities.
+In the worst case, simply do not define @emph{any} of the macros for missing
+subroutines.  When you compile @code{gawk}, the final link-editing step
+will fail.  The link editor will provide you with a list of unresolved external
+references---these are the missing subroutines.  Edit @file{config.h} again
+and recompile, and you should be set.@refill
+
+Editing the @file{Makefile} should also be straightforward.  Enable or
+disable the lines that begin with @samp{##MAKE_@var{whatever}##}, as
+appropriate.  Select the correct C compiler and @code{CFLAGS} for it.
+Then run @code{make}.
+
+Getting a correct configuration is likely to be an iterative process.
+Do not be discouraged if it takes you several tries.  If you have no
+luck whatsoever, please report your system type, and the steps you took.
+Once you do have a working configuration, please send it to the maintainers
+so that support for your system can be added to the official release.
+
+@xref{Bugs, ,Reporting Problems and Bugs}, for information on how to report
+problems in configuring @code{gawk}.  You may also use the same mechanisms
+for sending in new configurations.@refill
+
+@node VMS Installation, MS-DOS Installation, Unix Installation, Installation
+@section Compiling, Installing, and Running @code{gawk} on VMS
+
+@c based on material from
+@c Pat Rankin <rankin@eql.caltech.edu>
+
+@cindex installation, vms
+This section describes how to compile and install @code{gawk} under VMS.
+
+@menu
+* VMS Compilation::             How to compile @code{gawk} under VMS.
+* VMS Installation Details::    How to install @code{gawk} under VMS.
+* VMS Running::                 How to run @code{gawk} under VMS.
+* VMS POSIX::                   Alternate instructions for VMS POSIX.
+@end menu
+
+@node VMS Compilation, VMS Installation Details, VMS Installation, VMS Installation
+@subsection Compiling @code{gawk} under VMS
+
+To compile @code{gawk} under VMS, there is a @code{DCL} command procedure that
+will issue all the necessary @code{CC} and @code{LINK} commands, and there is
+also a @file{Makefile} for use with the @code{MMS} utility.  From the source
+directory, use either
+
+@smallexample
+$ @@[.VMS]VMSBUILD.COM
+@end smallexample
+
+@noindent
+or
+
+@smallexample
+$ MMS/DESCRIPTION=[.VMS]DECSRIP.MMS GAWK
+@end smallexample
+
+Depending upon which C compiler you are using, follow one of the sets
+of instructions in this table:
+
+@table @asis
+@item VAX C V3.x
+Use either @file{vmsbuild.com} or @file{descrip.mms} as is.  These use
+@code{CC/OPTIMIZE=NOLINE}, which is essential for Version 3.0.
+
+@item VAX C V2.x
+You must have Version 2.3 or 2.4; older ones won't work.  Edit either
+@file{vmsbuild.com} or @file{descrip.mms} according to the comments in them.
+For @file{vmsbuild.com}, this just entails removing two @samp{!} delimiters.
+Also edit @file{config.h} (which is a copy of file @file{[.config]vms-conf.h})
+and comment out or delete the two lines @samp{#define __STDC__ 0} and
+@samp{#define VAXC_BUILTINS} near the end.@refill
+
+@item GNU C
+Edit @file{vmsbuild.com} or @file{descrip.mms}; the changes are different
+from those for VAX C V2.x, but equally straightforward.  No changes to
+@file{config.h} should be needed.
+
+@item DEC C
+Edit @file{vmsbuild.com} or @file{descrip.mms} according to their comments.
+No changes to @file{config.h} should be needed.
+@end table
+
+@code{gawk} 2.15 has been tested under VAX/VMS 5.5-1 using VAX C V3.2,
+GNU C 1.40 and 2.3.  It should work without modifications for VMS V4.6 and up.
+
+@node VMS Installation Details, VMS Running, VMS Compilation, VMS Installation
+@subsection Installing @code{gawk} on VMS
+
+To install @code{gawk}, all you need is a ``foreign'' command, which is
+a @code{DCL} symbol whose value begins with a dollar sign.
+
+@smallexample
+$ GAWK :== $device:[directory]GAWK
+@end smallexample
+
+@noindent
+(Substitute the actual location of @code{gawk.exe} for
+@samp{device:[directory]}.) The symbol should be placed in the
+@file{login.com} of any user who wishes to run @code{gawk},
+so that it will be defined every time the user logs on.
+Alternatively, the symbol may be placed in the system-wide
+@file{sylogin.com} procedure, which will allow all users
+to run @code{gawk}.@refill
+
+Optionally, the help entry can be loaded into a VMS help library:
+
+@smallexample
+$ LIBRARY/HELP SYS$HELP:HELPLIB [.VMS]GAWK.HLP
+@end smallexample
+
+@noindent
+(You may want to substitute a site-specific help library rather than
+the standard VMS library @samp{HELPLIB}.)  After loading the help text,
+
+@c this is so tiny, but `should' be smallexample for consistency sake...
+@c I didn't because it was so short.  --mew 29jan1992
+@example
+$ HELP GAWK
+@end example
+
+@noindent
+will provide information about both the @code{gawk} implementation and the
+@code{awk} programming language.
+
+The logical name @samp{AWK_LIBRARY} can designate a default location
+for @code{awk} program files.  For the @samp{-f} option, if the specified
+filename has no device or directory path information in it, @code{gawk}
+will look in the current directory first, then in the directory specified
+by the translation of @samp{AWK_LIBRARY} if the file was not found.
+If after searching in both directories, the file still is not found,
+then @code{gawk} appends the suffix @samp{.awk} to the filename and the
+file search will be re-tried.  If @samp{AWK_LIBRARY} is not defined, that
+portion of the file search will fail benignly.@refill
+
+@node VMS Running, VMS POSIX, VMS Installation Details, VMS Installation
+@subsection Running @code{gawk} on VMS
+
+Command line parsing and quoting conventions are significantly different
+on VMS, so examples in this manual or from other sources often need minor
+changes.  They @emph{are} minor though, and all @code{awk} programs
+should run correctly.
+
+Here are a couple of trivial tests:
+
+@smallexample
+$ gawk -- "BEGIN @{print ""Hello, World!""@}"
+$ gawk -"W" version     ! could also be -"W version" or "-W version"
+@end smallexample
+
+@noindent
+Note that upper-case and mixed-case text must be quoted.
+
+The VMS port of @code{gawk} includes a @code{DCL}-style interface in addition
+to the original shell-style interface (see the help entry for details).
+One side-effect of dual command line parsing is that if there is only a
+single parameter (as in the quoted string program above), the command
+becomes ambiguous.  To work around this, the normally optional @samp{--}
+flag is required to force Unix style rather than @code{DCL} parsing.  If any
+other dash-type options (or multiple parameters such as data files to be
+processed) are present, there is no ambiguity and @samp{--} can be omitted.
+
+The default search path when looking for @code{awk} program files specified
+by the @samp{-f} option is @code{"SYS$DISK:[],AWK_LIBRARY:"}.  The logical
+name @samp{AWKPATH} can be used to override this default.  The format
+of @samp{AWKPATH} is a comma-separated list of directory specifications.
+When defining it, the value should be quoted so that it retains a single
+translation, and not a multi-translation @code{RMS} searchlist.
+
+@node VMS POSIX,  , VMS Running, VMS Installation
+@subsection Building and using @code{gawk} under VMS POSIX
+
+Ignore the instructions above, although @file{vms/gawk.hlp} should still
+be made available in a help library.  Make sure that the two scripts,
+@file{configure} and @file{mungeconf}, are executable; use @samp{chmod +x}
+on them if necessary.  Then execute the following commands:
+
+@smallexample
+$ POSIX
+psx> configure vms-posix
+psx> make awktab.c gawk
+@end smallexample
+
+@noindent
+The first command will construct files @file{config.h} and @file{Makefile}
+out of templates.  The second command will compile and link @code{gawk}.
+Due to a @code{make} bug in VMS POSIX V1.0 and V1.1,
+the file @file{awktab.c} must be given as an explicit target or it will
+not be built and the final link step will fail.  Ignore the warning
+@samp{"Could not find lib m in lib list"}; it is harmless, caused by the
+explicit use of @samp{-lm} as a linker option which is not needed
+under VMS POSIX.  Under V1.1 (but not V1.0) a problem with the @code{yacc}
+skeleton @file{/etc/yyparse.c} will cause a compiler warning for
+@file{awktab.c}, followed by a linker warning about compilation warnings
+in the resulting object module.  These warnings can be ignored.@refill
+
+Once built, @code{gawk} will work like any other shell utility.  Unlike
+the normal VMS port of @code{gawk}, no special command line manipulation is
+needed in the VMS POSIX environment.
+
+@node MS-DOS Installation, Atari Installation, VMS Installation, Installation
+@section Installing @code{gawk} on MS-DOS
+
+@cindex installation, ms-dos
+The first step is to get all the files in the @code{gawk} distribution
+onto your PC.  Move all the files from the @file{pc} directory into
+the main directory where the other files are.  Edit the file
+@file{make.bat} so that it will be an acceptable MS-DOS batch file.
+This means making sure that all lines are terminated with the ASCII
+carriage return and line feed characters.
+restrictions.
+
+@code{gawk} has only been compiled with version 5.1 of the Microsoft
+C compiler.  The file @file{make.bat} from the @file{pc} directory
+assumes that you have this compiler.
+
+Copy the file @file{setargv.obj} from the library directory where it
+resides to the @code{gawk} source code directory.
+
+Run @file{make.bat}.  This will compile @code{gawk} for you, and link it.
+That's all there is to it!
+
+@node Atari Installation,  , MS-DOS Installation, Installation
+@section Installing @code{gawk} on the Atari ST
+
+@c based on material from
+@c Michal Jaegermann <ntomczak@vm.ucs.ualberta.ca>
+
+@cindex installation, atari
+This section assumes that you are running TOS.  It applies to other Atari
+models (STe, TT) as well.
+
+In order to use @code{gawk}, you need to have a shell, either text or
+graphics, that does not map all the characters of a command line to
+upper case.  Maintaining case distinction in option flags is very
+important (@pxref{Command Line, ,Invoking @code{awk}}).  Popular shells
+like @code{gulam} or @code{gemini} will work, as will newer versions of
+@code{desktop}.  Support for I/O redirection is necessary to make it easy
+to import @code{awk} programs from other environments.  Pipes are nice to have,
+but not vital.
+
+If you have received an executable version of @code{gawk}, place it,
+as usual, anywhere in your @code{PATH} where your shell will find it.
+
+While executing, @code{gawk} creates a number of temporary files.
+@code{gawk} looks for either of the environment variables @code{TEMP}
+or @code{TMPDIR}, in that order.  If either one is found, its value
+is assumed to be a directory for temporary files.  This directory
+must exist, and if you can spare the memory, it is a good idea to
+put it on a @sc{ram} drive.  If neither @code{TEMP} nor @code{TMPDIR}
+are found, then @code{gawk} uses the current directory for its
+temporary files.
+
+The ST version of @code{gawk} searches for its program files as
+described in @ref{AWKPATH Variable, ,The @code{AWKPATH} Environment Variable}.
+On the ST, the default value for the @code{AWKPATH} variable is
+@code{@w{".,c:\lib\awk,c:\gnu\lib\awk"}}.
+The search path can be modified by explicitly setting @code{AWKPATH} to
+whatever you wish.  Note that colons cannot be used on the ST to separate
+elements in the @code{AWKPATH} variable, since they have another, reserved,
+meaning.  Instead, you must use a comma to separate elements in the path.
+If you are recompiling @code{gawk} on the ST, then you can choose a new
+default search path, by setting the value of @samp{DEFPATH} in the file
+@file{...\config\atari}.  You may choose a different separator character
+by setting the value of @samp{ENVSEP} in the same file.  The new values will
+be used when creating the header file @file{config.h}.@refill
+
+@ignore
+As a last resort, small
+adjustments can be made directly on the executable version of @code{gawk}
+using a binary editor.@refill
+@end ignore
+
+Although @code{awk} allows great flexibility in doing I/O redirections
+from within a program, this facility should be used with care on the ST.
+In some circumstances the OS routines for file handle pool processing
+lose track of certain events, causing the computer to crash, and requiring
+a reboot.  Often a warm reboot is sufficient.  Fortunately, this happens
+infrequently, and in rather esoteric situations.  In particular, avoid
+having one part of an @code{awk} program using @code{print}
+statements explicitly redirected to @code{"/dev/stdout"}, while other
+@code{print} statements use the default standard output, and a
+calling shell has redirected standard output to a file.@refill
+@c whew!
+
+When @code{gawk} is compiled with the ST version of @code{gcc} and its
+usual libraries, it will accept both @samp{/} and @samp{\} as path separators.
+While this is convenient, it should be remembered that this removes one,
+technically legal, character (@samp{/}) from your file names, and that
+it may create problems for external programs, called via the @code{system()}
+function, which may not support this convention.  Whenever it is possible
+that a file created by @code{gawk} will be used by some other program,
+use only backslashes.  Also remember that in @code{awk}, backslashes in
+strings have to be doubled in order to get literal backslashes.
+
+The initial port of @code{gawk} to the ST was done with @code{gcc}.
+If you wish to recompile @code{gawk} from scratch, you will need to use
+a compiler that accepts @sc{ansi} standard C (such as @code{gcc}, Turbo C,
+or Prospero C).  If @code{sizeof(int) != @w{sizeof(int *)}}, the correctness
+of the generated code depends heavily on the fact that all function calls
+have function prototypes in the current scope.  If your compiler does
+not accept function prototypes, you will probably have to add a
+number of casts to the code.@refill
+
+If you are using @code{gcc}, make sure that you have up-to-date libraries.
+Older versions have problems with some library functions (@code{atan2()},
+@code{strftime()}, the @samp{%g} conversion in @code{sprintf()}) which
+may affect the operation of @code{gawk}.
+
+In the @file{atari} subdirectory of the @code{gawk} distribution is
+a version of the @code{system()} function that has been tested with
+@code{gulam} and @code{msh}; it should work with other shells as well.
+With @code{gulam}, it passes the string to be executed without spawning
+an extra copy of a shell.  It is possible to replace this version of
+@code{system()} with a similar function from a library or from some other
+source if that version would be a better choice for the shell you prefer.
+
+The files needed to recompile @code{gawk} on the ST can be found in
+the @file{atari} directory.  The provided files and instructions below
+assume that you have the GNU C compiler (@code{gcc}), the @code{gulam} shell,
+and an ST version of @code{sed}. The @file{Makefile} is set up to use
+@file{byacc} as a @file{yacc} replacement.  With a different set of tools some
+adjustments and/or editing will be needed.@refill
+
+@code{cd} to the @file{atari} directory.  Copy @file{Makefile.st} to
+@file{makefile} in the source (parent) directory.  Possibly adjust
+@file{../config/atari} to suit your system.  Execute the script @file{mkconf.g}
+which will create the header file @file{../config.h}.  Go back to the source
+directory.  If you are not using @code{gcc}, check the file @file{missing.c}.
+It may be necessary to change forward slashes in the references to files
+from the @file{atari} subdirectory into backslashes.  Type @code{make} and
+enjoy.@refill
+
+Compilation with @code{gcc} of some of the bigger modules, like
+@file{awk_tab.c}, may require a full four megabytes of memory.  On smaller
+machines you would need to cut down on optimizations, or you would have to
+switch to another, less memory hungry, compiler.@refill
+
+@node Gawk Summary, Sample Program, Installation, Top
+@appendix @code{gawk} Summary
+
+This appendix provides a brief summary of the @code{gawk} command line and the
+@code{awk} language.  It is designed to serve as ``quick reference.''  It is
+therefore terse, but complete.
+
+@menu
+* Command Line Summary::        Recapitulation of the command line.
+* Language Summary::            A terse review of the language.
+* Variables/Fields::            Variables, fields, and arrays.
+* Rules Summary::               Patterns and Actions, and their 
+                                component parts.
+* Functions Summary::           Defining and calling functions.
+* Historical Features::         Some undocumented but supported ``features''.
+@end menu
+
+@node Command Line Summary, Language Summary, Gawk Summary, Gawk Summary
+@appendixsec Command Line Options Summary
+
+The command line consists of options to @code{gawk} itself, the
+@code{awk} program text (if not supplied via the @samp{-f} option), and
+values to be made available in the @code{ARGC} and @code{ARGV}
+predefined @code{awk} variables:
+
+@example
+awk @r{[@var{POSIX or GNU style options}]} -f source-file @r{[@code{--}]} @var{file} @dots{}
+awk @r{[@var{POSIX or GNU style options}]} @r{[@code{--}]} '@var{program}' @var{file} @dots{}
+@end example
+
+The options that @code{gawk} accepts are:
+
+@table @code
+@item -F @var{fs}
+@itemx --field-separator=@var{fs}
+Use @var{fs} for the input field separator (the value of the @code{FS}
+predefined variable).
+
+@item -f @var{program-file}
+@itemx --file=@var{program-file}
+Read the @code{awk} program source from the file @var{program-file}, instead
+of from the first command line argument.
+
+@item -v @var{var}=@var{val}
+@itemx --assign=@var{var}=@var{val}
+Assign the variable @var{var} the value @var{val} before program execution
+begins.
+
+@item -W compat
+@itemx --compat
+Specifies compatibility mode, in which @code{gawk} extensions are turned
+off.
+
+@item -W copyleft
+@itemx -W copyright
+@itemx --copyleft
+@itemx --copyright
+Print the short version of the General Public License on the error
+output.  This option may disappear in a future version of @code{gawk}.
+
+@item -W help
+@itemx -W usage
+@itemx --help
+@itemx --usage
+Print a relatively short summary of the available options on the error output.
+
+@item -W lint
+@itemx --lint
+Give warnings about dubious or non-portable @code{awk} constructs.
+
+@item -W posix
+@itemx --posix
+Specifies @sc{posix} compatibility mode, in which @code{gawk} extensions
+are turned off and additional restrictions apply.
+
+@item -W source=@var{program-text}
+@itemx --source=@var{program-text}
+Use @var{program-text} as @code{awk} program source code.  This option allows
+mixing command line source code with source code from files, and is
+particularly useful for mixing command line programs with library functions.
+
+@item -W version
+@itemx --version
+Print version information for this particular copy of @code{gawk} on the error
+output.  This option may disappear in a future version of @code{gawk}.
+
+@item --
+Signal the end of options.  This is useful to allow further arguments to the
+@code{awk} program itself to start with a @samp{-}.  This is mainly for
+consistency with the argument parsing conventions of @sc{posix}.
+@end table
+
+Any other options are flagged as invalid, but are otherwise ignored.
+@xref{Command Line, ,Invoking @code{awk}}, for more details.
+
+@node Language Summary, Variables/Fields, Command Line Summary, Gawk Summary
+@appendixsec Language Summary
+
+An @code{awk} program consists of a sequence of pattern-action statements
+and optional function definitions.
+
+@example
+@var{pattern}    @{ @var{action statements} @}
+
+function @var{name}(@var{parameter list})     @{ @var{action statements} @}
+@end example
+
+@code{gawk} first reads the program source from the
+@var{program-file}(s) if specified, or from the first non-option
+argument on the command line.  The @samp{-f} option may be used multiple
+times on the command line.  @code{gawk} reads the program text from all
+the @var{program-file} files, effectively concatenating them in the
+order they are specified.  This is useful for building libraries of
+@code{awk} functions, without having to include them in each new
+@code{awk} program that uses them.  To use a library function in a file
+from a program typed in on the command line, specify @samp{-f /dev/tty};
+then type your program, and end it with a @kbd{Control-d}.
+@xref{Command Line, ,Invoking @code{awk}}.@refill
+
+The environment variable @code{AWKPATH} specifies a search path to use
+when finding source files named with the @samp{-f} option.  The default
+path, which is
+@samp{.:/usr/lib/awk:/usr/local/lib/awk} is used if @code{AWKPATH} is not set.
+If a file name given to the @samp{-f} option contains a @samp{/} character,
+no path search is performed.
+@xref{AWKPATH Variable, ,The @code{AWKPATH} Environment Variable},
+for a full description of the @code{AWKPATH} environment variable.@refill
+
+@code{gawk} compiles the program into an internal form, and then proceeds to
+read each file named in the @code{ARGV} array.  If there are no files named
+on the command line, @code{gawk} reads the standard input.
+
+If a ``file'' named on the command line has the form
+@samp{@var{var}=@var{val}}, it is treated as a variable assignment: the
+variable @var{var} is assigned the value @var{val}.
+If any of the files have a value that is the null string, that
+element in the list is skipped.@refill
+
+For each line in the input, @code{gawk} tests to see if it matches any
+@var{pattern} in the @code{awk} program.  For each pattern that the line
+matches, the associated @var{action} is executed.
+
+@node Variables/Fields, Rules Summary, Language Summary, Gawk Summary
+@appendixsec Variables and Fields
+
+@code{awk} variables are dynamic; they come into existence when they are
+first used.  Their values are either floating-point numbers or strings.
+@code{awk} also has one-dimension arrays; multiple-dimensional arrays
+may be simulated.  There are several predefined variables that
+@code{awk} sets as a program runs; these are summarized below.
+
+@menu
+* Fields Summary::              Input field splitting.
+* Built-in Summary::            @code{awk}'s built-in variables.
+* Arrays Summary::              Using arrays.
+* Data Type Summary::           Values in @code{awk} are numbers or strings.
+@end menu
+
+@node Fields Summary, Built-in Summary, Variables/Fields, Variables/Fields
+@appendixsubsec Fields
+
+As each input line is read, @code{gawk} splits the line into
+@var{fields}, using the value of the @code{FS} variable as the field
+separator.  If @code{FS} is a single character, fields are separated by
+that character.  Otherwise, @code{FS} is expected to be a full regular
+expression.  In the special case that @code{FS} is a single blank,
+fields are separated by runs of blanks and/or tabs.  Note that the value
+of @code{IGNORECASE} (@pxref{Case-sensitivity, ,Case-sensitivity in Matching})
+also affects how fields are split when @code{FS} is a regular expression.@refill
+
+Each field in the input line may be referenced by its position, @code{$1},
+@code{$2}, and so on.  @code{$0} is the whole line.  The value of a field may
+be assigned to as well.  Field numbers need not be constants:
+
+@example
+n = 5
+print $n
+@end example
+
+@noindent
+prints the fifth field in the input line.  The variable @code{NF} is set to
+the total number of fields in the input line.
+
+References to nonexistent fields (i.e., fields after @code{$NF}) return
+the null-string.  However, assigning to a nonexistent field (e.g.,
+@code{$(NF+2) = 5}) increases the value of @code{NF}, creates any
+intervening fields with the null string as their value, and causes the
+value of @code{$0} to be recomputed, with the fields being separated by
+the value of @code{OFS}.@refill
+
+@xref{Reading Files, ,Reading Input Files}, for a full description of the
+way @code{awk} defines and uses fields.
+
+@node Built-in Summary, Arrays Summary, Fields Summary, Variables/Fields
+@appendixsubsec Built-in Variables
+
+@code{awk}'s built-in variables are:
+
+@table @code
+@item ARGC
+The number of command line arguments (not including options or the
+@code{awk} program itself).
+
+@item ARGIND
+The index in @code{ARGV} of the current file being processed.
+It is always true that @samp{FILENAME == ARGV[ARGIND]}.
+
+@item ARGV
+The array of command line arguments.  The array is indexed from 0 to
+@code{ARGC} @minus{} 1.  Dynamically changing the contents of @code{ARGV}
+can control the files used for data.@refill
+
+@item CONVFMT
+The conversion format to use when converting numbers to strings.
+
+@item FIELDWIDTHS
+A space separated list of numbers describing the fixed-width input data.
+
+@item ENVIRON
+An array containing the values of the environment variables.  The array
+is indexed by variable name, each element being the value of that
+variable.  Thus, the environment variable @code{HOME} would be in
+@code{ENVIRON["HOME"]}.  Its value might be @file{/u/close}.
+
+Changing this array does not affect the environment seen by programs
+which @code{gawk} spawns via redirection or the @code{system} function.
+(This may change in a future version of @code{gawk}.)
+
+Some operating systems do not have environment variables.
+The array @code{ENVIRON} is empty when running on these systems.
+
+@item ERRNO
+The system error message when an error occurs using @code{getline}
+or @code{close}.
+
+@item FILENAME
+The name of the current input file.  If no files are specified on the command
+line, the value of @code{FILENAME} is @samp{-}.
+
+@item FNR
+The input record number in the current input file.
+
+@item FS
+The input field separator, a blank by default.
+
+@item IGNORECASE
+The case-sensitivity flag for regular expression operations.  If
+@code{IGNORECASE} has a nonzero value, then pattern matching in rules,
+field splitting with @code{FS}, regular expression matching with
+@samp{~} and @samp{!~}, and the @code{gsub}, @code{index}, @code{match},
+@code{split} and @code{sub} predefined functions all ignore case
+when doing regular expression operations.@refill
+
+@item NF
+The number of fields in the current input record.
+
+@item NR
+The total number of input records seen so far.
+
+@item OFMT
+The output format for numbers for the @code{print} statement,
+@code{"%.6g"} by default.
+
+@item OFS
+The output field separator, a blank by default.
+
+@item ORS
+The output record separator, by default a newline.
+
+@item RS
+The input record separator, by default a newline.  @code{RS} is exceptional
+in that only the first character of its string value is used for separating
+records.  If @code{RS} is set to the null string, then records are separated by
+blank lines.  When @code{RS} is set to the null string, then the newline
+character always acts as a field separator, in addition to whatever value
+@code{FS} may have.@refill
+
+@item RSTART
+The index of the first character matched by @code{match}; 0 if no match.
+
+@item RLENGTH
+The length of the string matched by @code{match}; @minus{}1 if no match.
+
+@item SUBSEP
+The string used to separate multiple subscripts in array elements, by
+default @code{"\034"}.
+@end table
+
+@xref{Built-in Variables}, for more information.
+
+@node Arrays Summary, Data Type Summary, Built-in Summary, Variables/Fields
+@appendixsubsec Arrays
+
+Arrays are subscripted with an expression between square brackets
+(@samp{[} and @samp{]}).  Array subscripts are @emph{always} strings;
+numbers are converted to strings as necessary, following the standard
+conversion rules
+(@pxref{Conversion, ,Conversion of Strings and Numbers}).@refill
+
+If you use multiple expressions separated by commas inside the square
+brackets, then the array subscript is a string consisting of the
+concatenation of the individual subscript values, converted to strings,
+separated by the subscript separator (the value of @code{SUBSEP}).
+
+The special operator @code{in} may be used in an @code{if} or
+@code{while} statement to see if an array has an index consisting of a
+particular value.
+
+@example
+if (val in array)
+        print array[val]
+@end example
+
+If the array has multiple subscripts, use @code{(i, j, @dots{}) in array}
+to test for existence of an element.
+
+The @code{in} construct may also be used in a @code{for} loop to iterate
+over all the elements of an array.
+@xref{Scanning an Array, ,Scanning all Elements of an Array}.@refill
+
+An element may be deleted from an array using the @code{delete} statement.
+
+@xref{Arrays, ,Arrays in @code{awk}}, for more detailed information.
+
+@node Data Type Summary,  , Arrays Summary, Variables/Fields
+@appendixsubsec Data Types
+
+The value of an @code{awk} expression is always either a number
+or a string.
+
+Certain contexts (such as arithmetic operators) require numeric
+values.  They convert strings to numbers by interpreting the text
+of the string as a numeral.  If the string does not look like a
+numeral, it converts to 0.
+
+Certain contexts (such as concatenation) require string values.
+They convert numbers to strings by effectively printing them
+with @code{sprintf}.
+@xref{Conversion, ,Conversion of Strings and Numbers}, for the details.@refill
+
+To force conversion of a string value to a number, simply add 0
+to it.  If the value you start with is already a number, this
+does not change it.
+
+To force conversion of a numeric value to a string, concatenate it with
+the null string.
+
+The @code{awk} language defines comparisons as being done numerically if
+both operands are numeric, or if one is numeric and the other is a numeric
+string.  Otherwise one or both operands are converted to strings and a
+string comparison is performed.
+
+Uninitialized variables have the string value @code{""} (the null, or
+empty, string).  In contexts where a number is required, this is
+equivalent to 0.
+
+@xref{Variables}, for more information on variable naming and initialization;
+@pxref{Conversion, ,Conversion of Strings and Numbers}, for more information
+on how variable values are interpreted.@refill
+
+@node Rules Summary, Functions Summary, Variables/Fields, Gawk Summary
+@appendixsec Patterns and Actions
+
+@menu
+* Pattern Summary::             Quick overview of patterns.
+* Regexp Summary::              Quick overview of regular expressions.
+* Actions Summary::             Quick overview of actions.
+@end menu
+
+An @code{awk} program is mostly composed of rules, each consisting of a
+pattern followed by an action.  The action is enclosed in @samp{@{} and
+@samp{@}}.  Either the pattern may be missing, or the action may be
+missing, but, of course, not both.  If the pattern is missing, the
+action is executed for every single line of input.  A missing action is
+equivalent to this action,
+
+@example
+@{ print @}
+@end example
+
+@noindent
+which prints the entire line.
+
+Comments begin with the @samp{#} character, and continue until the end of the
+line.  Blank lines may be used to separate statements.  Normally, a statement
+ends with a newline, however, this is not the case for lines ending in a
+@samp{,}, @samp{@{}, @samp{?}, @samp{:}, @samp{&&}, or @samp{||}.  Lines
+ending in @code{do} or @code{else} also have their statements automatically
+continued on the following line.  In other cases, a line can be continued by
+ending it with a @samp{\}, in which case the newline is ignored.@refill
+
+Multiple statements may be put on one line by separating them with a @samp{;}.
+This applies to both the statements within the action part of a rule (the
+usual case), and to the rule statements.
+
+@xref{Comments, ,Comments in @code{awk} Programs}, for information on
+@code{awk}'s commenting convention;
+@pxref{Statements/Lines, ,@code{awk} Statements versus Lines}, for a
+description of the line continuation mechanism in @code{awk}.@refill
+
+@node Pattern Summary, Regexp Summary, Rules Summary, Rules Summary
+@appendixsubsec Patterns
+
+@code{awk} patterns may be one of the following:
+
+@example
+/@var{regular expression}/
+@var{relational expression}
+@var{pattern} && @var{pattern}
+@var{pattern} || @var{pattern}
+@var{pattern} ? @var{pattern} : @var{pattern}
+(@var{pattern})
+! @var{pattern}
+@var{pattern1}, @var{pattern2}
+BEGIN
+END
+@end example
+
+@code{BEGIN} and @code{END} are two special kinds of patterns that are not
+tested against the input.  The action parts of all @code{BEGIN} rules are
+merged as if all the statements had been written in a single @code{BEGIN}
+rule.  They are executed before any of the input is read.  Similarly, all the
+@code{END} rules are merged, and executed when all the input is exhausted (or
+when an @code{exit} statement is executed).  @code{BEGIN} and @code{END}
+patterns cannot be combined with other patterns in pattern expressions.
+@code{BEGIN} and @code{END} rules cannot have missing action parts.@refill
+
+For @samp{/@var{regular-expression}/} patterns, the associated statement is
+executed for each input line that matches the regular expression.  Regular
+expressions are extensions of those in @code{egrep}, and are summarized below.
+
+A @var{relational expression} may use any of the operators defined below in
+the section on actions.  These generally test whether certain fields match
+certain regular expressions.
+
+The @samp{&&}, @samp{||}, and @samp{!} operators are logical ``and,''
+logical ``or,'' and logical ``not,'' respectively, as in C.  They do
+short-circuit evaluation, also as in C, and are used for combining more
+primitive pattern expressions.  As in most languages, parentheses may be
+used to change the order of evaluation.
+
+The @samp{?:} operator is like the same operator in C.  If the first
+pattern matches, then the second pattern is matched against the input
+record; otherwise, the third is matched.  Only one of the second and
+third patterns is matched.
+
+The @samp{@var{pattern1}, @var{pattern2}} form of a pattern is called a
+range pattern.  It matches all input lines starting with a line that
+matches @var{pattern1}, and continuing until a line that matches
+@var{pattern2}, inclusive.  A range pattern cannot be used as an operand
+to any of the pattern operators.
+
+@xref{Patterns}, for a full description of the pattern part of @code{awk}
+rules.
+
+@node Regexp Summary, Actions Summary, Pattern Summary, Rules Summary
+@appendixsubsec Regular Expressions
+
+Regular expressions are the extended kind found in @code{egrep}.
+They are composed of characters as follows:
+
+@table @code
+@item @var{c}
+matches the character @var{c} (assuming @var{c} is a character with no
+special meaning in regexps).
+
+@item \@var{c}
+matches the literal character @var{c}.
+
+@item .
+matches any character except newline.
+
+@item ^
+matches the beginning of a line or a string.
+
+@item $
+matches the end of a line or a string.
+
+@item [@var{abc}@dots{}]
+matches any of the characters @var{abc}@dots{} (character class).
+
+@item [^@var{abc}@dots{}]
+matches any character except @var{abc}@dots{} and newline (negated
+character class).
+
+@item @var{r1}|@var{r2}
+matches either @var{r1} or @var{r2} (alternation).
+
+@item @var{r1r2}
+matches @var{r1}, and then @var{r2} (concatenation).
+
+@item @var{r}+
+matches one or more @var{r}'s.
+
+@item @var{r}*
+matches zero or more @var{r}'s. 
+
+@item @var{r}?
+matches zero or one @var{r}'s. 
+
+@item (@var{r})
+matches @var{r} (grouping).
+@end table
+
+@xref{Regexp, ,Regular Expressions as Patterns}, for a more detailed
+explanation of regular expressions.
+
+The escape sequences allowed in string constants are also valid in
+regular expressions (@pxref{Constants, ,Constant Expressions}).
+
+@node Actions Summary,  , Regexp Summary, Rules Summary
+@appendixsubsec Actions
+
+Action statements are enclosed in braces, @samp{@{} and @samp{@}}.
+Action statements consist of the usual assignment, conditional, and looping
+statements found in most languages.  The operators, control statements,
+and input/output statements available are patterned after those in C.
+
+@menu
+* Operator Summary::            @code{awk} operators.
+* Control Flow Summary::        The control statements.
+* I/O Summary::                 The I/O statements.
+* Printf Summary::              A summary of @code{printf}.
+* Special File Summary::        Special file names interpreted internally.
+* Numeric Functions Summary::   Built-in numeric functions.
+* String Functions Summary::    Built-in string functions.
+* Time Functions Summary::      Built-in time functions.
+* String Constants Summary::    Escape sequences in strings.
+@end menu
+
+@node Operator Summary, Control Flow Summary, Actions Summary, Actions Summary
+@appendixsubsubsec Operators
+
+The operators in @code{awk}, in order of increasing precedence, are:
+
+@table @code
+@item = += -= *= /= %= ^=
+Assignment.  Both absolute assignment (@code{@var{var}=@var{value}})
+and operator assignment (the other forms) are supported.
+
+@item ?:
+A conditional expression, as in C.  This has the form @code{@var{expr1} ?
+@var{expr2} : @var{expr3}}.  If @var{expr1} is true, the value of the
+expression is @var{expr2}; otherwise it is @var{expr3}.  Only one of
+@var{expr2} and @var{expr3} is evaluated.@refill
+
+@item ||
+Logical ``or''.
+
+@item &&
+Logical ``and''.
+
+@item ~ !~
+Regular expression match, negated match.
+
+@item < <= > >= != ==
+The usual relational operators.
+
+@item @var{blank}
+String concatenation.
+
+@item + -
+Addition and subtraction.
+
+@item * / %
+Multiplication, division, and modulus.
+
+@item + - !
+Unary plus, unary minus, and logical negation.
+
+@item ^
+Exponentiation (@samp{**} may also be used, and @samp{**=} for the assignment
+operator, but they are not specified in the @sc{posix} standard).
+
+@item ++ --
+Increment and decrement, both prefix and postfix.
+
+@item $
+Field reference.
+@end table
+
+@xref{Expressions, ,Expressions as Action Statements}, for a full
+description of all the operators listed above.
+@xref{Fields, ,Examining Fields}, for a description of the field
+reference operator.@refill
+
+@node Control Flow Summary, I/O Summary, Operator Summary, Actions Summary
+@appendixsubsubsec Control Statements
+
+The control statements are as follows:
+
+@example
+if (@var{condition}) @var{statement} @r{[} else @var{statement} @r{]}
+while (@var{condition}) @var{statement}
+do @var{statement} while (@var{condition})
+for (@var{expr1}; @var{expr2}; @var{expr3}) @var{statement}
+for (@var{var} in @var{array}) @var{statement}
+break
+continue
+delete @var{array}[@var{index}]
+exit @r{[} @var{expression} @r{]}
+@{ @var{statements} @}
+@end example
+
+@xref{Statements, ,Control Statements in Actions}, for a full description
+of all the control statements listed above.
+
+@node I/O Summary, Printf Summary, Control Flow Summary, Actions Summary
+@appendixsubsubsec I/O Statements
+
+The input/output statements are as follows:
+
+@table @code
+@item getline
+Set @code{$0} from next input record; set @code{NF}, @code{NR}, @code{FNR}.
+
+@item getline <@var{file}
+Set @code{$0} from next record of @var{file}; set @code{NF}.
+
+@item getline @var{var}
+Set @var{var} from next input record; set @code{NF}, @code{FNR}.
+
+@item getline @var{var} <@var{file}
+Set @var{var} from next record of @var{file}.
+
+@item next
+Stop processing the current input record.  The next input record is read and
+processing starts over with the first pattern in the @code{awk} program.
+If the end of the input data is reached, the @code{END} rule(s), if any,
+are executed.
+
+@item next file
+Stop processing the current input file.  The next input record read comes
+from the next input file.  @code{FILENAME} is updated, @code{FNR} is set to 1, 
+and processing starts over with the first pattern in the @code{awk} program.
+If the end of the input data is reached, the @code{END} rule(s), if any,
+are executed.
+
+@item print
+Prints the current record.
+
+@item print @var{expr-list}
+Prints expressions.
+
+@item print @var{expr-list} > @var{file}
+Prints expressions on @var{file}.
+
+@item printf @var{fmt, expr-list}
+Format and print.
+
+@item printf @var{fmt, expr-list} > file
+Format and print on @var{file}.
+@end table
+
+Other input/output redirections are also allowed.  For @code{print} and
+@code{printf}, @samp{>> @var{file}} appends output to the @var{file},
+and @samp{| @var{command}} writes on a pipe.  In a similar fashion,
+@samp{@var{command} | getline} pipes input into @code{getline}.
+@code{getline} returns 0 on end of file, and @minus{}1 on an error.@refill
+
+@xref{Getline, ,Explicit Input with @code{getline}}, for a full description
+of the @code{getline} statement.
+@xref{Printing, ,Printing Output}, for a full description of @code{print} and
+@code{printf}.  Finally, @pxref{Next Statement, ,The @code{next} Statement},
+for a description of how the @code{next} statement works.@refill
+
+@node Printf Summary, Special File Summary, I/O Summary, Actions Summary
+@appendixsubsubsec @code{printf} Summary
+
+The @code{awk} @code{printf} statement and @code{sprintf} function
+accept the following conversion specification formats:
+
+@table @code
+@item %c
+An ASCII character.  If the argument used for @samp{%c} is numeric, it is
+treated as a character and printed.  Otherwise, the argument is assumed to
+be a string, and the only first character of that string is printed.
+
+@item %d
+@itemx %i
+A decimal number (the integer part).
+
+@item %e
+A floating point number of the form
+@samp{@r{[}-@r{]}d.ddddddE@r{[}+-@r{]}dd}.@refill
+
+@item %f
+A floating point number of the form
+@r{[}@code{-}@r{]}@code{ddd.dddddd}.
+
+@item %g
+Use @samp{%e} or @samp{%f} conversion, whichever produces a shorter string,
+with nonsignificant zeros suppressed.
+
+@item %o
+An unsigned octal number (again, an integer).
+
+@item %s
+A character string.
+
+@item %x
+An unsigned hexadecimal number (an integer).
+
+@item %X
+Like @samp{%x}, except use @samp{A} through @samp{F} instead of @samp{a}
+through @samp{f} for decimal 10 through 15.@refill
+
+@item %%
+A single @samp{%} character; no argument is converted.
+@end table
+
+There are optional, additional parameters that may lie between the @samp{%}
+and the control letter:
+
+@table @code
+@item -
+The expression should be left-justified within its field.
+
+@item @var{width}
+The field should be padded to this width.  If @var{width} has a leading zero,
+then the field is padded with zeros.  Otherwise it is padded with blanks.
+
+@item .@var{prec}
+A number indicating the maximum width of strings or digits to the right
+of the decimal point.
+@end table
+
+Either or both of the @var{width} and @var{prec} values may be specified
+as @samp{*}.  In that case, the particular value is taken from the argument
+list.
+
+@xref{Printf, ,Using @code{printf} Statements for Fancier Printing}, for
+examples and for a more detailed description.
+
+@node Special File Summary, Numeric Functions Summary, Printf Summary, Actions Summary
+@appendixsubsubsec Special File Names
+
+When doing I/O redirection from either @code{print} or @code{printf} into a
+file, or via @code{getline} from a file, @code{gawk} recognizes certain special
+file names internally.  These file names allow access to open file descriptors
+inherited from @code{gawk}'s parent process (usually the shell).  The
+file names are:
+
+@table @file
+@item /dev/stdin
+The standard input.
+
+@item /dev/stdout
+The standard output.
+
+@item /dev/stderr
+The standard error output.
+
+@item /dev/fd/@var{n}
+The file denoted by the open file descriptor @var{n}.
+@end table
+
+In addition the following files provide process related information
+about the running @code{gawk} program.
+
+@table @file
+@item /dev/pid
+Reading this file returns the process ID of the current process,
+in decimal, terminated with a newline.
+
+@item  /dev/ppid
+Reading this file returns the parent process ID of the current process,
+in decimal, terminated with a newline.
+
+@item  /dev/pgrpid
+Reading this file returns the process group ID of the current process,
+in decimal, terminated with a newline.
+
+@item /dev/user
+Reading this file returns a single record terminated with a newline.
+The fields are separated with blanks.  The fields represent the
+following information:
+
+@table @code
+@item $1
+The value of the @code{getuid} system call.
+
+@item $2
+The value of the @code{geteuid} system call.
+
+@item $3
+The value of the @code{getgid} system call.
+
+@item $4
+The value of the @code{getegid} system call.
+@end table
+
+If there are any additional fields, they are the group IDs returned by
+@code{getgroups} system call.
+(Multiple groups may not be supported on all systems.)@refill
+@end table
+
+@noindent
+These file names may also be used on the command line to name data files.
+These file names are only recognized internally if you do not
+actually have files by these names on your system.
+
+@xref{Special Files, ,Standard I/O Streams}, for a longer description that
+provides the motivation for this feature.
+
+@node Numeric Functions Summary, String Functions Summary, Special File Summary, Actions Summary
+@appendixsubsubsec Numeric Functions
+
+@code{awk} has the following predefined arithmetic functions:
+
+@table @code
+@item atan2(@var{y}, @var{x})
+returns the arctangent of @var{y/x} in radians.
+
+@item cos(@var{expr})
+returns the cosine in radians.
+
+@item exp(@var{expr})
+the exponential function.
+
+@item int(@var{expr})
+truncates to integer.
+
+@item log(@var{expr})
+the natural logarithm function.
+
+@item rand()
+returns a random number between 0 and 1.
+
+@item sin(@var{expr})
+returns the sine in radians.
+
+@item sqrt(@var{expr})
+the square root function.
+
+@item srand(@var{expr})
+use @var{expr} as a new seed for the random number generator.  If no @var{expr}
+is provided, the time of day is used.  The return value is the previous
+seed for the random number generator.
+@end table
+
+@node String Functions Summary, Time Functions Summary, Numeric Functions Summary, Actions Summary
+@appendixsubsubsec String Functions
+
+@code{awk} has the following predefined string functions:
+
+@table @code
+@item gsub(@var{r}, @var{s}, @var{t})
+for each substring matching the regular expression @var{r} in the string
+@var{t}, substitute the string @var{s}, and return the number of substitutions.
+If @var{t} is not supplied, use @code{$0}.
+
+@item index(@var{s}, @var{t})
+returns the index of the string @var{t} in the string @var{s}, or 0 if
+@var{t} is not present.
+
+@item length(@var{s})
+returns the length of the string @var{s}.  The length of @code{$0}
+is returned if no argument is supplied.
+
+@item match(@var{s}, @var{r})
+returns the position in @var{s} where the regular expression @var{r}
+occurs, or 0 if @var{r} is not present, and sets the values of @code{RSTART}
+and @code{RLENGTH}.
+
+@item split(@var{s}, @var{a}, @var{r})
+splits the string @var{s} into the array @var{a} on the regular expression
+@var{r}, and returns the number of fields.  If @var{r} is omitted, @code{FS}
+is used instead.
+
+@item sprintf(@var{fmt}, @var{expr-list})
+prints @var{expr-list} according to @var{fmt}, and returns the resulting string.
+
+@item sub(@var{r}, @var{s}, @var{t})
+this is just like @code{gsub}, but only the first matching substring is
+replaced.
+
+@item substr(@var{s}, @var{i}, @var{n})
+returns the @var{n}-character substring of @var{s} starting at @var{i}.
+If @var{n} is omitted, the rest of @var{s} is used.
+
+@item tolower(@var{str})
+returns a copy of the string @var{str}, with all the upper-case characters in
+@var{str} translated to their corresponding lower-case counterparts.
+Nonalphabetic characters are left unchanged.
+
+@item toupper(@var{str})
+returns a copy of the string @var{str}, with all the lower-case characters in
+@var{str} translated to their corresponding upper-case counterparts.
+Nonalphabetic characters are left unchanged.
+
+@item system(@var{cmd-line})
+Execute the command @var{cmd-line}, and return the exit status.
+@end table
+
+@node Time Functions Summary, String Constants Summary, String Functions Summary, Actions Summary
+@appendixsubsubsec  Built-in time functions
+
+The following two functions are available for getting the current
+time of day, and for formatting time stamps.
+
+@table @code
+@item systime()
+returns the current time of day as the number of seconds since a particular
+epoch (Midnight, January 1, 1970 @sc{utc}, on @sc{posix} systems).
+
+@item strftime(@var{format}, @var{timestamp})
+formats @var{timestamp} according to the specification in @var{format}.
+The current time of day is used if no @var{timestamp} is supplied.
+@xref{Time Functions, ,Functions for Dealing with Time Stamps}, for the
+details on the conversion specifiers that @code{strftime} accepts.@refill
+@end table
+
+@iftex
+@xref{Built-in, ,Built-in Functions}, for a description of all of
+@code{awk}'s built-in functions.
+@end iftex
+
+@node String Constants Summary,  , Time Functions Summary, Actions Summary
+@appendixsubsubsec String Constants
+
+String constants in @code{awk} are sequences of characters enclosed
+between double quotes (@code{"}).  Within strings, certain @dfn{escape sequences}
+are recognized, as in C.  These are:
+
+@table @code
+@item \\
+A literal backslash.
+
+@item \a
+The ``alert'' character; usually the ASCII BEL character.
+
+@item \b
+Backspace.
+
+@item \f
+Formfeed.
+
+@item \n
+Newline.
+
+@item \r
+Carriage return.
+
+@item \t
+Horizontal tab.
+
+@item \v
+Vertical tab.
+
+@item \x@var{hex digits}
+The character represented by the string of hexadecimal digits following
+the @samp{\x}.  As in @sc{ansi} C, all following hexadecimal digits are
+considered part of the escape sequence.  (This feature should tell us
+something about language design by committee.)  E.g., @code{"\x1B"} is a
+string containing the ASCII ESC (escape) character.  (The @samp{\x}
+escape sequence is not in @sc{posix} @code{awk}.)
+
+@item \@var{ddd}
+The character represented by the 1-, 2-, or 3-digit sequence of octal
+digits.  Thus, @code{"\033"} is also a string containing the ASCII ESC
+(escape) character.
+
+@item \@var{c}
+The literal character @var{c}.
+@end table
+
+The escape sequences may also be used inside constant regular expressions
+(e.g., the regexp @code{@w{/[@ \t\f\n\r\v]/}} matches whitespace
+characters).@refill
+
+@xref{Constants, ,Constant Expressions}.
+
+@node Functions Summary, Historical Features, Rules Summary, Gawk Summary
+@appendixsec Functions
+
+Functions in @code{awk} are defined as follows:
+
+@example
+function @var{name}(@var{parameter list}) @{ @var{statements} @}
+@end example
+
+Actual parameters supplied in the function call are used to instantiate
+the formal parameters declared in the function.  Arrays are passed by
+reference, other variables are passed by value.
+
+If there are fewer arguments passed than there are names in @var{parameter-list},
+the extra names are given the null string as value.  Extra names have the
+effect of local variables.
+
+The open-parenthesis in a function call of a user-defined function must
+immediately follow the function name, without any intervening white space.
+This is to avoid a syntactic ambiguity with the concatenation operator.
+
+The word @code{func} may be used in place of @code{function} (but not in
+@sc{posix} @code{awk}).
+
+Use the @code{return} statement to return a value from a function.
+
+@xref{User-defined, ,User-defined Functions}, for a more complete description.
+
+@node Historical Features,  , Functions Summary, Gawk Summary
+@appendixsec Historical Features
+
+There are two features of historical @code{awk} implementations that
+@code{gawk} supports.  First, it is possible to call the @code{length}
+built-in function not only with no arguments, but even without parentheses!
+
+@example
+a = length
+@end example
+
+@noindent
+is the same as either of
+
+@example
+a = length()
+a = length($0)
+@end example
+
+@noindent
+This feature is marked as ``deprecated'' in the @sc{posix} standard, and
+@code{gawk} will issue a warning about its use if @samp{-W lint} is
+specified on the command line.
+
+The other feature is the use of the @code{continue} statement outside the
+body of a @code{while}, @code{for}, or @code{do} loop.  Traditional
+@code{awk} implementations have treated such usage as equivalent to the
+@code{next} statement.  @code{gawk} will support this usage if @samp{-W posix}
+has not been specified.
+
+@node Sample Program, Bugs, Gawk Summary, Top
+@appendix Sample Program
+
+The following example is a complete @code{awk} program, which prints
+the number of occurrences of each word in its input.  It illustrates the
+associative nature of @code{awk} arrays by using strings as subscripts.  It
+also demonstrates the @samp{for @var{x} in @var{array}} construction.
+Finally, it shows how @code{awk} can be used in conjunction with other
+utility programs to do a useful task of some complexity with a minimum of
+effort.  Some explanations follow the program listing.@refill
+
+@example
+awk '
+# Print list of word frequencies
+@{
+    for (i = 1; i <= NF; i++)
+        freq[$i]++
+@}
+
+END @{
+    for (word in freq)
+        printf "%s\t%d\n", word, freq[word]
+@}'
+@end example
+
+The first thing to notice about this program is that it has two rules.  The
+first rule, because it has an empty pattern, is executed on every line of
+the input.  It uses @code{awk}'s field-accessing mechanism
+(@pxref{Fields, ,Examining Fields}) to pick out the individual words from
+the line, and the built-in variable @code{NF} (@pxref{Built-in Variables})
+to know how many fields are available.@refill
+
+For each input word, an element of the array @code{freq} is incremented to
+reflect that the word has been seen an additional time.@refill
+
+The second rule, because it has the pattern @code{END}, is not executed
+until the input has been exhausted.  It prints out the contents of the
+@code{freq} table that has been built up inside the first action.@refill
+
+Note that this program has several problems that would prevent it from being
+useful by itself on real text files:@refill
+
+@itemize @bullet
+@item
+Words are detected using the @code{awk} convention that fields are
+separated by whitespace and that other characters in the input (except
+newlines) don't have any special meaning to @code{awk}.  This means that
+punctuation characters count as part of words.@refill
+
+@item
+The @code{awk} language considers upper and lower case characters to be
+distinct.  Therefore, @samp{foo} and @samp{Foo} are not treated by this
+program as the same word.  This is undesirable since in normal text, words
+are capitalized if they begin sentences, and a frequency analyzer should not
+be sensitive to that.@refill
+
+@item
+The output does not come out in any useful order.  You're more likely to be
+interested in which words occur most frequently, or having an alphabetized
+table of how frequently each word occurs.@refill
+@end itemize
+
+The way to solve these problems is to use some of the more advanced
+features of the @code{awk} language.  First, we use @code{tolower} to remove
+case distinctions.  Next, we use @code{gsub} to remove punctuation
+characters.  Finally, we use the system @code{sort} utility to process the
+output of the @code{awk} script.  First, here is the new version of
+the program:@refill
+
+@example
+awk '
+# Print list of word frequencies
+@{
+    $0 = tolower($0)    # remove case distinctions
+    gsub(/[^a-z0-9_ \t]/, "", $0)  # remove punctuation
+    for (i = 1; i <= NF; i++)
+        freq[$i]++
+@}
+
+END @{
+    for (word in freq)
+        printf "%s\t%d\n", word, freq[word]
+@}'
+@end example
+
+Assuming we have saved this program in a file named @file{frequency.awk},
+and that the data is in @file{file1}, the following pipeline
+
+@example
+awk -f frequency.awk file1 | sort +1 -nr
+@end example
+
+@noindent
+produces a table of the words appearing in @file{file1} in order of
+decreasing frequency.
+
+The @code{awk} program suitably massages the data and produces a word
+frequency table, which is not ordered.
+
+The @code{awk} script's output is then sorted by the @code{sort} command and
+printed on the terminal.  The options given to @code{sort} in this example
+specify to sort using the second field of each input line (skipping one field),
+that the sort keys should be treated as numeric quantities (otherwise
+@samp{15} would come before @samp{5}), and that the sorting should be done
+in descending (reverse) order.@refill
+
+We could have even done the @code{sort} from within the program, by
+changing the @code{END} action to:
+
+@example
+END @{
+    sort = "sort +1 -nr"
+    for (word in freq)
+        printf "%s\t%d\n", word, freq[word] | sort
+    close(sort)
+@}'
+@end example
+
+See the general operating system documentation for more information on how
+to use the @code{sort} command.@refill
+
+@ignore
+@strong{ADR: I have some more substantial programs courtesy of Rick Adams
+at UUNET.  I am planning on incorporating those either in addition to or
+instead of this program.}
+
+@strong{I would also like to incorporate the general @code{translate}
+function that I have written.}
+
+@strong{I have a ton of other sample programs to include too.}
+@end ignore
+
+@node Bugs, Notes, Sample Program, Top
+@appendix Reporting Problems and Bugs
+
+@c This chapter stolen shamelessly from the GNU m4 manual.
+@c This chapter has been unshamelessly altered to emulate changes made to
+@c make.texi from whence it was originally shamelessly stolen! :-} --mew
+
+If you have problems with @code{gawk} or think that you have found a bug,
+please report it to the developers; we cannot promise to do anything
+but we might well want to fix it.
+
+Before reporting a bug, make sure you have actually found a real bug.
+Carefully reread the documentation and see if it really says you can do
+what you're trying to do.  If it's not clear whether you should be able
+to do something or not, report that too; it's a bug in the documentation!
+
+Before reporting a bug or trying to fix it yourself, try to isolate it
+to the smallest possible @code{awk} program and input data file that
+reproduces the problem.  Then send us the program and data file,
+some idea of what kind of Unix system you're using, and the exact results
+@code{gawk} gave you.  Also say what you expected to occur; this will help
+us decide whether the problem was really in the documentation.
+
+Once you have a precise problem, send e-mail to (Internet)
+@samp{bug-gnu-utils@@prep.ai.mit.edu} or (UUCP)
+@samp{mit-eddie!prep.ai.mit.edu!bug-gnu-utils}.  Please include the
+version number of @code{gawk} you are using.  You can get this information
+with the command @samp{gawk -W version '@{@}' /dev/null}.
+You should send carbon copies of your mail to David Trueman at
+@samp{david@@cs.dal.ca}, and to Arnold Robbins, who can be reached at
+@samp{arnold@@skeeve.atl.ga.us}.  David is most likely to fix code
+problems, while Arnold is most likely to fix documentation problems.@refill
+
+Non-bug suggestions are always welcome as well.  If you have questions
+about things that are unclear in the documentation or are just obscure
+features, ask Arnold Robbins; he will try to help you out, although he
+may not have the time to fix the problem.  You can send him electronic mail at the Internet address
+above.
+
+If you find bugs in one of the non-Unix ports of @code{gawk}, please send
+an electronic mail message to the person who maintains that port.  They
+are listed below, and also in the @file{README} file in the @code{gawk}
+distribution.  Information in the @code{README} file should be considered
+authoritative if it conflicts with this manual.
+
+The people maintaining the non-Unix ports of @code{gawk} are:
+
+@table @asis
+@item MS-DOS
+The port to MS-DOS is maintained by Scott Deifik.
+His electronic mail address is @samp{scottd@@amgen.com}.
+
+@item VMS
+The port to VAX VMS is maintained by Pat Rankin.
+His electronic mail address is @samp{rankin@@eql.caltech.edu}.
+
+@item Atari ST
+The port to the Atari ST is maintained by Michal Jaegermann.
+His electronic mail address is @samp{ntomczak@@vm.ucs.ualberta.ca}.
+
+@end table
+
+If your bug is also reproducible under Unix, please send copies of your
+report to the general GNU bug list, as well as to Arnold Robbins and David
+Trueman, at the addresses listed above.
+
+@node Notes, Glossary, Bugs, Top
+@appendix Implementation Notes
+
+This appendix contains information mainly of interest to implementors and
+maintainers of @code{gawk}.  Everything in it applies specifically to
+@code{gawk}, and not to other implementations.
+
+@menu
+* Compatibility Mode::          How to disable certain @code{gawk} extensions.
+* Future Extensions::           New features we may implement soon.
+* Improvements::                Suggestions for improvements by volunteers.
+@end menu
+
+@node Compatibility Mode, Future Extensions, Notes, Notes
+@appendixsec Downward Compatibility and Debugging
+
+@xref{POSIX/GNU, ,Extensions in @code{gawk} not in POSIX @code{awk}},
+for a summary of the GNU extensions to the @code{awk} language and program.
+All of these features can be turned off by invoking @code{gawk} with the
+@samp{-W compat} option, or with the @samp{-W posix} option.@refill
+
+If @code{gawk} is compiled for debugging with @samp{-DDEBUG}, then there
+is one more option available on the command line:
+
+@table @samp
+@item -W parsedebug
+Print out the parse stack information as the program is being parsed.
+@end table
+
+This option is intended only for serious @code{gawk} developers,
+and not for the casual user.  It probably has not even been compiled into
+your version of @code{gawk}, since it slows down execution.
+
+@node Future Extensions, Improvements, Compatibility Mode, Notes
+@appendixsec Probable Future Extensions
+
+This section briefly lists extensions that indicate the directions we are
+currently considering for @code{gawk}.  The file @file{FUTURES} in the
+@code{gawk} distributions lists these extensions, as well as several others.
+
+@table @asis
+@item @code{RS} as a regexp
+The meaning of @code{RS} may be generalized along the lines of @code{FS}.
+
+@item Control of subprocess environment
+Changes made in @code{gawk} to the array @code{ENVIRON} may be
+propagated to subprocesses run by @code{gawk}.
+
+@item Databases
+It may be possible to map a GDBM/NDBM/SDBM file into an @code{awk} array.
+
+@item Single-character fields
+The null string, @code{""}, as a field separator, will cause field
+splitting and the @code{split} function to separate individual characters.
+Thus, @code{split(a, "abcd", "")} would yield @code{a[1] == "a"},
+@code{a[2] == "b"}, and so on.
+
+@item More @code{lint} warnings
+There are more things that could be checked for portability.
+
+@item @code{RECLEN} variable for fixed length records
+Along with @code{FIELDWIDTHS}, this would speed up the processing of
+fixed-length records.
+
+@item @code{RT} variable to hold the record terminator
+It is occasionally useful to have access to the actual string of
+characters that matched the @code{RS} variable.  The @code{RT}
+variable would hold these characters.
+
+@item A @code{restart} keyword
+After modifying @code{$0}, @code{restart} would restart the pattern
+matching loop, without reading a new record from the input.
+
+@item A @samp{|&} redirection
+The @samp{|&} redirection, in place of @samp{|}, would open a two-way
+pipeline for communication with a sub-process (via @code{getline} and
+@code{print} and @code{printf}).
+
+@item @code{IGNORECASE} affecting all comparisons
+The effects of the @code{IGNORECASE} variable may be generalized to
+all string comparisons, and not just regular expression operations.
+
+@item A way to mix command line source code and library files
+There may be a new option that would make it possible to easily use library
+functions from a program entered on the command line.
+@c probably a @samp{-s} option...
+
+@item GNU-style long options
+We will add GNU-style long options
+to @code{gawk} for compatibility with other GNU programs.
+(For example, @samp{--field-separator=:} would be equivalent to
+@samp{-F:}.)@refill
+
+@c this is @emph{very} long term --- not worth including right now.
+@ignore
+@item The C Comma Operator
+We may add the C comma operator, which takes the form
+@code{@var{expr1},@var{expr2}}.  The first expression is evaluated, and the
+result is thrown away.  The value of the full expression is the value of
+@var{expr2}.@refill
+@end ignore
+@end table
+
+@node Improvements,  , Future Extensions, Notes
+@appendixsec Suggestions for Improvements
+
+Here are some projects that would-be @code{gawk} hackers might like to take
+on.  They vary in size from a few days to a few weeks of programming,
+depending on which one you choose and how fast a programmer you are.  Please
+send any improvements you write to the maintainers at the GNU
+project.@refill
+
+@enumerate
+@item
+Compilation of @code{awk} programs: @code{gawk} uses a Bison (YACC-like)
+parser to convert the script given it into a syntax tree; the syntax
+tree is then executed by a simple recursive evaluator.  This method incurs
+a lot of overhead, since the recursive evaluator performs many procedure
+calls to do even the simplest things.@refill
+
+It should be possible for @code{gawk} to convert the script's parse tree
+into a C program which the user would then compile, using the normal
+C compiler and a special @code{gawk} library to provide all the needed
+functions (regexps, fields, associative arrays, type coercion, and so
+on).@refill
+
+An easier possibility might be for an intermediate phase of @code{awk} to
+convert the parse tree into a linear byte code form like the one used
+in GNU Emacs Lisp.  The recursive evaluator would then be replaced by
+a straight line byte code interpreter that would be intermediate in speed
+between running a compiled program and doing what @code{gawk} does
+now.@refill
+
+This may actually happen for the 3.0 version of @code{gawk}.
+
+@item
+An error message section has not been included in this version of the
+manual.  Perhaps some nice beta testers will document some of the messages
+for the future.
+
+@item
+The programs in the test suite could use documenting in this manual.
+
+@item
+The programs and data files in the manual should be available in
+separate files to facilitate experimentation.
+
+@item
+See the @file{FUTURES} file for more ideas.  Contact us if you would
+seriously like to tackle any of the items listed there.
+@end enumerate
+
+@node Glossary, Index, Notes, Top
+@appendix Glossary
+
+@table @asis
+@item Action
+A series of @code{awk} statements attached to a rule.  If the rule's
+pattern matches an input record, the @code{awk} language executes the
+rule's action.  Actions are always enclosed in curly braces.
+@xref{Actions, ,Overview of Actions}.@refill
+
+@item Amazing @code{awk} Assembler
+Henry Spencer at the University of Toronto wrote a retargetable assembler
+completely as @code{awk} scripts.  It is thousands of lines long, including
+machine descriptions for several 8-bit microcomputers.
+@c It is distributed with @code{gawk} (as part of the test suite) and
+It is a good example of a
+program that would have been better written in another language.@refill
+
+@item @sc{ansi}
+The American National Standards Institute.  This organization produces
+many standards, among them the standard for the C programming language.
+
+@item Assignment
+An @code{awk} expression that changes the value of some @code{awk}
+variable or data object.  An object that you can assign to is called an
+@dfn{lvalue}.  @xref{Assignment Ops, ,Assignment Expressions}.@refill
+
+@item @code{awk} Language
+The language in which @code{awk} programs are written.
+
+@item @code{awk} Program
+An @code{awk} program consists of a series of @dfn{patterns} and
+@dfn{actions}, collectively known as @dfn{rules}.  For each input record
+given to the program, the program's rules are all processed in turn.
+@code{awk} programs may also contain function definitions.@refill
+
+@item @code{awk} Script
+Another name for an @code{awk} program.
+
+@item Built-in Function
+The @code{awk} language provides built-in functions that perform various
+numerical, time stamp related, and string computations.  Examples are
+@code{sqrt} (for the square root of a number) and @code{substr} (for a
+substring of a string).  @xref{Built-in, ,Built-in Functions}.@refill
+
+@item Built-in Variable
+@code{ARGC}, @code{ARGIND}, @code{ARGV}, @code{CONVFMT}, @code{ENVIRON},
+@code{ERRNO}, @code{FIELDWIDTHS}, @code{FILENAME}, @code{FNR}, @code{FS},
+@code{IGNORECASE}, @code{NF}, @code{NR}, @code{OFMT}, @code{OFS}, @code{ORS},
+@code{RLENGTH}, @code{RSTART}, @code{RS}, and @code{SUBSEP},
+are the variables that have special
+meaning to @code{awk}.  Changing some of them affects @code{awk}'s running
+environment.  @xref{Built-in Variables}.@refill
+
+@item Braces
+See ``Curly Braces.''
+
+@item C
+The system programming language that most GNU software is written in.  The
+@code{awk} programming language has C-like syntax, and this manual
+points out similarities between @code{awk} and C when appropriate.@refill
+
+@item CHEM
+A preprocessor for @code{pic} that reads descriptions of molecules
+and produces @code{pic} input for drawing them.  It was written by
+Brian Kernighan, and is available from @code{netlib@@research.att.com}.@refill
+
+@item Compound Statement
+A series of @code{awk} statements, enclosed in curly braces.  Compound
+statements may be nested.
+@xref{Statements, ,Control Statements in Actions}.@refill
+
+@item Concatenation
+Concatenating two strings means sticking them together, one after another,
+giving a new string.  For example, the string @samp{foo} concatenated with
+the string @samp{bar} gives the string @samp{foobar}.
+@xref{Concatenation, ,String Concatenation}.@refill
+
+@item Conditional Expression
+An expression using the @samp{?:} ternary operator, such as
+@code{@var{expr1} ? @var{expr2} : @var{expr3}}.  The expression
+@var{expr1} is evaluated; if the result is true, the value of the whole
+expression is the value of @var{expr2} otherwise the value is
+@var{expr3}.  In either case, only one of @var{expr2} and @var{expr3}
+is evaluated.  @xref{Conditional Exp, ,Conditional Expressions}.@refill
+
+@item Constant Regular Expression
+A constant regular expression is a regular expression written within
+slashes, such as @samp{/foo/}.  This regular expression is chosen
+when you write the @code{awk} program, and cannot be changed doing
+its execution.  @xref{Regexp Usage, ,How to Use Regular Expressions}.
+
+@item Comparison Expression
+A relation that is either true or false, such as @code{(a < b)}.
+Comparison expressions are used in @code{if}, @code{while}, and @code{for}
+statements, and in patterns to select which input records to process.
+@xref{Comparison Ops, ,Comparison Expressions}.@refill
+
+@item Curly Braces
+The characters @samp{@{} and @samp{@}}.  Curly braces are used in
+@code{awk} for delimiting actions, compound statements, and function
+bodies.@refill
+
+@item Data Objects
+These are numbers and strings of characters.  Numbers are converted into
+strings and vice versa, as needed.
+@xref{Conversion, ,Conversion of Strings and Numbers}.@refill
+
+@item Dynamic Regular Expression
+A dynamic regular expression is a regular expression written as an
+ordinary expression.  It could be a string constant, such as
+@code{"foo"}, but it may also be an expression whose value may vary.
+@xref{Regexp Usage, ,How to Use Regular Expressions}.
+
+@item Escape Sequences
+A special sequence of characters used for describing nonprinting
+characters, such as @samp{\n} for newline, or @samp{\033} for the ASCII
+ESC (escape) character.  @xref{Constants, ,Constant Expressions}.
+
+@item Field
+When @code{awk} reads an input record, it splits the record into pieces
+separated by whitespace (or by a separator regexp which you can
+change by setting the built-in variable @code{FS}).  Such pieces are
+called fields.  If the pieces are of fixed length, you can use the built-in
+variable @code{FIELDWIDTHS} to describe their lengths.
+@xref{Records, ,How Input is Split into Records}.@refill
+
+@item Format
+Format strings are used to control the appearance of output in the
+@code{printf} statement.  Also, data conversions from numbers to strings
+are controlled by the format string contained in the built-in variable
+@code{CONVFMT}.  @xref{Control Letters, ,Format-Control Letters}.@refill
+
+@item Function
+A specialized group of statements often used to encapsulate general
+or program-specific tasks.  @code{awk} has a number of built-in
+functions, and also allows you to define your own.
+@xref{Built-in, ,Built-in Functions}.
+Also, see @ref{User-defined, ,User-defined Functions}.@refill
+
+@item @code{gawk}
+The GNU implementation of @code{awk}.
+
+@item GNU
+``GNU's not Unix''.  An on-going project of the Free Software Foundation
+to create a complete, freely distributable, @sc{posix}-compliant computing
+environment.
+
+@item Input Record
+A single chunk of data read in by @code{awk}.  Usually, an @code{awk} input
+record consists of one line of text.
+@xref{Records, ,How Input is Split into Records}.@refill
+
+@item Keyword
+In the @code{awk} language, a keyword is a word that has special
+meaning.  Keywords are reserved and may not be used as variable names.
+
+@code{awk}'s keywords are:
+@code{if},
+@code{else},
+@code{while},
+@code{do@dots{}while},
+@code{for},
+@code{for@dots{}in},
+@code{break},
+@code{continue},
+@code{delete},
+@code{next},
+@code{function},
+@code{func},
+and @code{exit}.@refill
+
+@item Lvalue
+An expression that can appear on the left side of an assignment
+operator.  In most languages, lvalues can be variables or array
+elements.  In @code{awk}, a field designator can also be used as an
+lvalue.@refill
+
+@item Number
+A numeric valued data object.  The @code{gawk} implementation uses double
+precision floating point to represent numbers.@refill
+
+@item Pattern
+Patterns tell @code{awk} which input records are interesting to which
+rules.
+
+A pattern is an arbitrary conditional expression against which input is
+tested.  If the condition is satisfied, the pattern is said to @dfn{match}
+the input record.  A typical pattern might compare the input record against
+a regular expression.  @xref{Patterns}.@refill
+
+@item @sc{posix}
+The name for a series of standards being developed by the @sc{ieee}
+that specify a Portable Operating System interface.  The ``IX'' denotes
+the Unix heritage of these standards.  The main standard of interest for
+@code{awk} users is P1003.2, the Command Language and Utilities standard.
+
+@item Range (of input lines)
+A sequence of consecutive lines from the input file.  A pattern
+can specify ranges of input lines for @code{awk} to process, or it can
+specify single lines.  @xref{Patterns}.@refill
+
+@item Recursion
+When a function calls itself, either directly or indirectly.
+If this isn't clear, refer to the entry for ``recursion.''
+
+@item Redirection
+Redirection means performing input from other than the standard input
+stream, or output to other than the standard output stream.
+
+You can redirect the output of the @code{print} and @code{printf} statements
+to a file or a system command, using the @samp{>}, @samp{>>}, and @samp{|}
+operators.  You can redirect input to the @code{getline} statement using
+the @samp{<} and @samp{|} operators.
+@xref{Redirection, ,Redirecting Output of @code{print} and @code{printf}}.@refill
+
+@item Regular Expression
+See ``regexp.''
+
+@item Regexp
+Short for @dfn{regular expression}.  A regexp is a pattern that denotes a
+set of strings, possibly an infinite set.  For example, the regexp
+@samp{R.*xp} matches any string starting with the letter @samp{R}
+and ending with the letters @samp{xp}.  In @code{awk}, regexps are
+used in patterns and in conditional expressions.  Regexps may contain
+escape sequences.  @xref{Regexp, ,Regular Expressions as Patterns}.@refill
+
+@item Rule
+A segment of an @code{awk} program, that specifies how to process single
+input records.  A rule consists of a @dfn{pattern} and an @dfn{action}.
+@code{awk} reads an input record; then, for each rule, if the input record
+satisfies the rule's pattern, @code{awk} executes the rule's action.
+Otherwise, the rule does nothing for that input record.@refill
+
+@item Side Effect
+A side effect occurs when an expression has an effect aside from merely
+producing a value.  Assignment expressions, increment expressions and
+function calls have side effects.  @xref{Assignment Ops, ,Assignment Expressions}.
+
+@item Special File
+A file name interpreted internally by @code{gawk}, instead of being handed
+directly to the underlying operating system.  For example, @file{/dev/stdin}.
+@xref{Special Files, ,Standard I/O Streams}.
+
+@item Stream Editor
+A program that reads records from an input stream and processes them one
+or more at a time.  This is in contrast with batch programs, which may
+expect to read their input files in entirety before starting to do
+anything, and with interactive programs, which require input from the
+user.@refill
+
+@item String
+A datum consisting of a sequence of characters, such as @samp{I am a
+string}.  Constant strings are written with double-quotes in the
+@code{awk} language, and may contain escape sequences.
+@xref{Constants, ,Constant Expressions}.
+
+@item Whitespace
+A sequence of blank or tab characters occurring inside an input record or a
+string.@refill
+@end table
+
+@node Index,  , Glossary, Top
+@unnumbered Index
+@printindex cp
+
+@summarycontents
+@contents
+@bye
+
+Unresolved Issues:
+------------------
+1. From: ntomczak@vm.ucs.ualberta.ca (Michal Jaegermann)
+   Examples of usage tend to suggest that /../ and ".." delimiters
+   can be used for regular expressions, even if definition is consistently
+   using /../.  I am not sure what the real rules are and in particular
+   what of the following is a bug and what is a feature:
+   # This program matches everything
+      '"\(" { print }'
+   # This one complains about mismatched parenthesis
+      '$0 ~ "\(" { print }'
+   # This one behaves in an expected manner
+      '/\(/ { print }'
+   You may also try to use "\(" as an argument to match() to see what
+   will happen.
+
+2. From ADR.
+
+   The posix (and original Unix!) notion of awk values as both number
+   and string values needs to be put into the manual.  This involves
+   major and minor rewrites of most of the manual, but should help in
+   clarifying many of the weirder points of the language.
+
+3. From ADR.
+
+   The manual should be reorganized.  Expressions should be introduced
+   early, building up to regexps as expressions, and from there to their
+   use as patterns and then in actions.  Built-in vars should come earlier
+   in the manual too.  The 'expert info' sections marked with comments
+   should get their own sections or subsections with nodes and titles.
+   The manual should be gone over thoroughly for indexing.
+
+4. From ADR.
+
+   Robert J. Chassell points out that awk programs should have some indication
+   of how to use them.  It would be useful to perhaps have a "programming
+   style" section of the manual that would include this and other tips.
+
+5. From ADR in response to moraes@uunet.ca
+   (This would make the beginnings of a good "puzzles" section...)
+
+   Date: Mon, 2 Dec 91 10:08:05 EST
+   From: gatech!cc!arnold (Arnold Robbins)
+   To: cs.dal.ca!david, uunet.ca!moraes
+   Subject: redirecting to /dev/stderr
+   Cc: skeeve!arnold, boeing.com!brennan, research.att.com!bwk
+   
+   In 2.13.3 the following program no longer dumps core:
+   
+   	BEGIN { print "hello" > /dev/stderr ; exit(1) }
+   
+   Instead, it creates a file named `0' with the word `hello' in it. AWK
+   semantics strikes again.  The meaning of the statement is
+   
+   		print "hello" > (($0 ~ /dev/) stderr)
+   
+   /dev/ tests $0 for the pattern `dev'.  This yields a 0.  The variable stderr,
+   having never been used, has a null string in it.  The concatenation yields
+   a string value of "0" which is used as the file name.  Sigh.
+   
+   I think with some more time I can come up with a decent fix, but it will
+   probably only print a diagnostic with -Wlint.
+   
+   Arnold
+
diff --git a/gnu/usr.bin/awk/getopt.c b/gnu/usr.bin/awk/getopt.c
new file mode 100644
index 000000000000..bbf345c33ca2
--- /dev/null
+++ b/gnu/usr.bin/awk/getopt.c
@@ -0,0 +1,662 @@
+/* Getopt for GNU.
+   NOTE: getopt is now part of the C library, so if you don't know what
+   "Keep this file name-space clean" means, talk to roland@gnu.ai.mit.edu
+   before changing it!
+
+   Copyright (C) 1987, 88, 89, 90, 91, 1992 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Library General Public License as published
+   by the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#ifdef GAWK
+#include "config.h"
+#endif
+
+#include <stdio.h>
+
+/* This needs to come after some library #include
+   to get __GNU_LIBRARY__ defined.  */
+#ifdef	__GNU_LIBRARY__
+#include <stdlib.h>
+#include <string.h>
+#endif	/* GNU C library.  */
+
+
+#ifndef __STDC__
+#define const
+#endif
+
+/* If GETOPT_COMPAT is defined, `+' as well as `--' can introduce a
+   long-named option.  Because this is not POSIX.2 compliant, it is
+   being phased out. */
+#define GETOPT_COMPAT
+
+/* This version of `getopt' appears to the caller like standard Unix `getopt'
+   but it behaves differently for the user, since it allows the user
+   to intersperse the options with the other arguments.
+
+   As `getopt' works, it permutes the elements of ARGV so that,
+   when it is done, all the options precede everything else.  Thus
+   all application programs are extended to handle flexible argument order.
+
+   Setting the environment variable POSIXLY_CORRECT disables permutation.
+   Then the behavior is completely standard.
+
+   GNU application programs can use a third alternative mode in which
+   they can distinguish the relative order of options and other arguments.  */
+
+#include "getopt.h"
+
+/* For communication from `getopt' to the caller.
+   When `getopt' finds an option that takes an argument,
+   the argument value is returned here.
+   Also, when `ordering' is RETURN_IN_ORDER,
+   each non-option ARGV-element is returned here.  */
+
+char *optarg = 0;
+
+/* Index in ARGV of the next element to be scanned.
+   This is used for communication to and from the caller
+   and for communication between successive calls to `getopt'.
+
+   On entry to `getopt', zero means this is the first call; initialize.
+
+   When `getopt' returns EOF, this is the index of the first of the
+   non-option elements that the caller should itself scan.
+
+   Otherwise, `optind' communicates from one call to the next
+   how much of ARGV has been scanned so far.  */
+
+int optind = 0;
+
+/* The next char to be scanned in the option-element
+   in which the last option character we returned was found.
+   This allows us to pick up the scan where we left off.
+
+   If this is zero, or a null string, it means resume the scan
+   by advancing to the next ARGV-element.  */
+
+static char *nextchar;
+
+/* Callers store zero here to inhibit the error message
+   for unrecognized options.  */
+
+int opterr = 1;
+
+/* Describe how to deal with options that follow non-option ARGV-elements.
+
+   If the caller did not specify anything,
+   the default is REQUIRE_ORDER if the environment variable
+   POSIXLY_CORRECT is defined, PERMUTE otherwise.
+
+   REQUIRE_ORDER means don't recognize them as options;
+   stop option processing when the first non-option is seen.
+   This is what Unix does.
+   This mode of operation is selected by either setting the environment
+   variable POSIXLY_CORRECT, or using `+' as the first character
+   of the list of option characters.
+
+   PERMUTE is the default.  We permute the contents of ARGV as we scan,
+   so that eventually all the non-options are at the end.  This allows options
+   to be given in any order, even with programs that were not written to
+   expect this.
+
+   RETURN_IN_ORDER is an option available to programs that were written
+   to expect options and other ARGV-elements in any order and that care about
+   the ordering of the two.  We describe each non-option ARGV-element
+   as if it were the argument of an option with character code 1.
+   Using `-' as the first character of the list of option characters
+   selects this mode of operation.
+
+   The special argument `--' forces an end of option-scanning regardless
+   of the value of `ordering'.  In the case of RETURN_IN_ORDER, only
+   `--' can cause `getopt' to return EOF with `optind' != ARGC.  */
+
+static enum
+{
+  REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER
+} ordering;
+
+#ifdef	__GNU_LIBRARY__
+#include <string.h>
+#define	my_index	strchr
+#define	my_bcopy(src, dst, n)	memcpy ((dst), (src), (n))
+#else
+
+/* Avoid depending on library functions or files
+   whose names are inconsistent.  */
+
+char *getenv ();
+
+static char *
+my_index (string, chr)
+     char *string;
+     int chr;
+{
+  while (*string)
+    {
+      if (*string == chr)
+	return string;
+      string++;
+    }
+  return 0;
+}
+
+static void
+my_bcopy (from, to, size)
+     char *from, *to;
+     int size;
+{
+  int i;
+  for (i = 0; i < size; i++)
+    to[i] = from[i];
+}
+#endif				/* GNU C library.  */
+
+/* Handle permutation of arguments.  */
+
+/* Describe the part of ARGV that contains non-options that have
+   been skipped.  `first_nonopt' is the index in ARGV of the first of them;
+   `last_nonopt' is the index after the last of them.  */
+
+static int first_nonopt;
+static int last_nonopt;
+
+/* Exchange two adjacent subsequences of ARGV.
+   One subsequence is elements [first_nonopt,last_nonopt)
+   which contains all the non-options that have been skipped so far.
+   The other is elements [last_nonopt,optind), which contains all
+   the options processed since those non-options were skipped.
+
+   `first_nonopt' and `last_nonopt' are relocated so that they describe
+   the new indices of the non-options in ARGV after they are moved.  */
+
+static void
+exchange (argv)
+     char **argv;
+{
+  int nonopts_size = (last_nonopt - first_nonopt) * sizeof (char *);
+  char **temp = (char **) malloc (nonopts_size);
+
+  /* Interchange the two blocks of data in ARGV.  */
+
+  my_bcopy (&argv[first_nonopt], temp, nonopts_size);
+  my_bcopy (&argv[last_nonopt], &argv[first_nonopt],
+	    (optind - last_nonopt) * sizeof (char *));
+  my_bcopy (temp, &argv[first_nonopt + optind - last_nonopt], nonopts_size);
+
+  free(temp);
+
+  /* Update records for the slots the non-options now occupy.  */
+
+  first_nonopt += (optind - last_nonopt);
+  last_nonopt = optind;
+}
+
+/* Scan elements of ARGV (whose length is ARGC) for option characters
+   given in OPTSTRING.
+
+   If an element of ARGV starts with '-', and is not exactly "-" or "--",
+   then it is an option element.  The characters of this element
+   (aside from the initial '-') are option characters.  If `getopt'
+   is called repeatedly, it returns successively each of the option characters
+   from each of the option elements.
+
+   If `getopt' finds another option character, it returns that character,
+   updating `optind' and `nextchar' so that the next call to `getopt' can
+   resume the scan with the following option character or ARGV-element.
+
+   If there are no more option characters, `getopt' returns `EOF'.
+   Then `optind' is the index in ARGV of the first ARGV-element
+   that is not an option.  (The ARGV-elements have been permuted
+   so that those that are not options now come last.)
+
+   OPTSTRING is a string containing the legitimate option characters.
+   If an option character is seen that is not listed in OPTSTRING,
+   return '?' after printing an error message.  If you set `opterr' to
+   zero, the error message is suppressed but we still return '?'.
+
+   If a char in OPTSTRING is followed by a colon, that means it wants an arg,
+   so the following text in the same ARGV-element, or the text of the following
+   ARGV-element, is returned in `optarg'.  Two colons mean an option that
+   wants an optional arg; if there is text in the current ARGV-element,
+   it is returned in `optarg', otherwise `optarg' is set to zero.
+
+   If OPTSTRING starts with `-' or `+', it requests different methods of
+   handling the non-option ARGV-elements.
+   See the comments about RETURN_IN_ORDER and REQUIRE_ORDER, above.
+
+   Long-named options begin with `--' instead of `-'.
+   Their names may be abbreviated as long as the abbreviation is unique
+   or is an exact match for some defined option.  If they have an
+   argument, it follows the option name in the same ARGV-element, separated
+   from the option name by a `=', or else the in next ARGV-element.
+   When `getopt' finds a long-named option, it returns 0 if that option's
+   `flag' field is nonzero, the value of the option's `val' field
+   if the `flag' field is zero.
+
+   The elements of ARGV aren't really const, because we permute them.
+   But we pretend they're const in the prototype to be compatible
+   with other systems.
+
+   LONGOPTS is a vector of `struct option' terminated by an
+   element containing a name which is zero.
+
+   LONGIND returns the index in LONGOPT of the long-named option found.
+   It is only valid when a long-named option has been found by the most
+   recent call.
+
+   If LONG_ONLY is nonzero, '-' as well as '--' can introduce
+   long-named options.  */
+
+int
+_getopt_internal (argc, argv, optstring, longopts, longind, long_only)
+     int argc;
+     char *const *argv;
+     const char *optstring;
+     const struct option *longopts;
+     int *longind;
+     int long_only;
+{
+  int option_index;
+
+  optarg = 0;
+
+  /* Initialize the internal data when the first call is made.
+     Start processing options with ARGV-element 1 (since ARGV-element 0
+     is the program name); the sequence of previously skipped
+     non-option ARGV-elements is empty.  */
+
+  if (optind == 0)
+    {
+      first_nonopt = last_nonopt = optind = 1;
+
+      nextchar = NULL;
+
+      /* Determine how to handle the ordering of options and nonoptions.  */
+
+      if (optstring[0] == '-')
+	{
+	  ordering = RETURN_IN_ORDER;
+	  ++optstring;
+	}
+      else if (optstring[0] == '+')
+	{
+	  ordering = REQUIRE_ORDER;
+	  ++optstring;
+	}
+      else if (getenv ("POSIXLY_CORRECT") != NULL)
+	ordering = REQUIRE_ORDER;
+      else
+	ordering = PERMUTE;
+    }
+
+  if (nextchar == NULL || *nextchar == '\0')
+    {
+      if (ordering == PERMUTE)
+	{
+	  /* If we have just processed some options following some non-options,
+	     exchange them so that the options come first.  */
+
+	  if (first_nonopt != last_nonopt && last_nonopt != optind)
+	    exchange ((char **) argv);
+	  else if (last_nonopt != optind)
+	    first_nonopt = optind;
+
+	  /* Now skip any additional non-options
+	     and extend the range of non-options previously skipped.  */
+
+	  while (optind < argc
+		 && (argv[optind][0] != '-' || argv[optind][1] == '\0')
+#ifdef GETOPT_COMPAT
+		 && (longopts == NULL
+		     || argv[optind][0] != '+' || argv[optind][1] == '\0')
+#endif				/* GETOPT_COMPAT */
+		 )
+	    optind++;
+	  last_nonopt = optind;
+	}
+
+      /* Special ARGV-element `--' means premature end of options.
+	 Skip it like a null option,
+	 then exchange with previous non-options as if it were an option,
+	 then skip everything else like a non-option.  */
+
+      if (optind != argc && !strcmp (argv[optind], "--"))
+	{
+	  optind++;
+
+	  if (first_nonopt != last_nonopt && last_nonopt != optind)
+	    exchange ((char **) argv);
+	  else if (first_nonopt == last_nonopt)
+	    first_nonopt = optind;
+	  last_nonopt = argc;
+
+	  optind = argc;
+	}
+
+      /* If we have done all the ARGV-elements, stop the scan
+	 and back over any non-options that we skipped and permuted.  */
+
+      if (optind == argc)
+	{
+	  /* Set the next-arg-index to point at the non-options
+	     that we previously skipped, so the caller will digest them.  */
+	  if (first_nonopt != last_nonopt)
+	    optind = first_nonopt;
+	  return EOF;
+	}
+
+      /* If we have come to a non-option and did not permute it,
+	 either stop the scan or describe it to the caller and pass it by.  */
+
+      if ((argv[optind][0] != '-' || argv[optind][1] == '\0')
+#ifdef GETOPT_COMPAT
+	  && (longopts == NULL
+	      || argv[optind][0] != '+' || argv[optind][1] == '\0')
+#endif				/* GETOPT_COMPAT */
+	  )
+	{
+	  if (ordering == REQUIRE_ORDER)
+	    return EOF;
+	  optarg = argv[optind++];
+	  return 1;
+	}
+
+      /* We have found another option-ARGV-element.
+	 Start decoding its characters.  */
+
+      nextchar = (argv[optind] + 1
+		  + (longopts != NULL && argv[optind][1] == '-'));
+    }
+
+  if (longopts != NULL
+      && ((argv[optind][0] == '-'
+	   && (argv[optind][1] == '-' || long_only))
+#ifdef GETOPT_COMPAT
+	  || argv[optind][0] == '+'
+#endif				/* GETOPT_COMPAT */
+	  ))
+    {
+      const struct option *p;
+      char *s = nextchar;
+      int exact = 0;
+      int ambig = 0;
+      const struct option *pfound = NULL;
+      int indfound = 0;
+      extern int strncmp();
+
+      while (*s && *s != '=')
+	s++;
+
+      /* Test all options for either exact match or abbreviated matches.  */
+      for (p = longopts, option_index = 0; p->name;
+	   p++, option_index++)
+	if (!strncmp (p->name, nextchar, s - nextchar))
+	  {
+	    if (s - nextchar == strlen (p->name))
+	      {
+		/* Exact match found.  */
+		pfound = p;
+		indfound = option_index;
+		exact = 1;
+		break;
+	      }
+	    else if (pfound == NULL)
+	      {
+		/* First nonexact match found.  */
+		pfound = p;
+		indfound = option_index;
+	      }
+	    else
+	      /* Second nonexact match found.  */
+	      ambig = 1;
+	  }
+
+      if (ambig && !exact)
+	{
+	  if (opterr)
+	    fprintf (stderr, "%s: option `%s' is ambiguous\n",
+		     argv[0], argv[optind]);
+	  nextchar += strlen (nextchar);
+	  optind++;
+	  return '?';
+	}
+
+      if (pfound != NULL)
+	{
+	  option_index = indfound;
+	  optind++;
+	  if (*s)
+	    {
+	      /* Don't test has_arg with >, because some C compilers don't
+		 allow it to be used on enums. */
+	      if (pfound->has_arg)
+		optarg = s + 1;
+	      else
+		{
+		  if (opterr)
+		    {
+		      if (argv[optind - 1][1] == '-')
+			/* --option */
+			fprintf (stderr,
+				 "%s: option `--%s' doesn't allow an argument\n",
+				 argv[0], pfound->name);
+		      else
+			/* +option or -option */
+			fprintf (stderr,
+			     "%s: option `%c%s' doesn't allow an argument\n",
+			     argv[0], argv[optind - 1][0], pfound->name);
+		    }
+		  nextchar += strlen (nextchar);
+		  return '?';
+		}
+	    }
+	  else if (pfound->has_arg == 1)
+	    {
+	      if (optind < argc)
+		optarg = argv[optind++];
+	      else
+		{
+		  if (opterr)
+		    fprintf (stderr, "%s: option `%s' requires an argument\n",
+			     argv[0], argv[optind - 1]);
+		  nextchar += strlen (nextchar);
+		  return '?';
+		}
+	    }
+	  nextchar += strlen (nextchar);
+	  if (longind != NULL)
+	    *longind = option_index;
+	  if (pfound->flag)
+	    {
+	      *(pfound->flag) = pfound->val;
+	      return 0;
+	    }
+	  return pfound->val;
+	}
+      /* Can't find it as a long option.  If this is not getopt_long_only,
+	 or the option starts with '--' or is not a valid short
+	 option, then it's an error.
+	 Otherwise interpret it as a short option. */
+      if (!long_only || argv[optind][1] == '-'
+#ifdef GETOPT_COMPAT
+	  || argv[optind][0] == '+'
+#endif				/* GETOPT_COMPAT */
+	  || my_index (optstring, *nextchar) == NULL)
+	{
+	  if (opterr)
+	    {
+	      if (argv[optind][1] == '-')
+		/* --option */
+		fprintf (stderr, "%s: unrecognized option `--%s'\n",
+			 argv[0], nextchar);
+	      else
+		/* +option or -option */
+		fprintf (stderr, "%s: unrecognized option `%c%s'\n",
+			 argv[0], argv[optind][0], nextchar);
+	    }
+	  nextchar = (char *) "";
+	  optind++;
+	  return '?';
+	}
+    }
+
+  /* Look at and handle the next option-character.  */
+
+  {
+    char c = *nextchar++;
+    char *temp = my_index (optstring, c);
+
+    /* Increment `optind' when we start to process its last character.  */
+    if (*nextchar == '\0')
+      ++optind;
+
+    if (temp == NULL || c == ':')
+      {
+	if (opterr)
+	  {
+	    if (c < 040 || c >= 0177)
+	      fprintf (stderr, "%s: unrecognized option, character code 0%o\n",
+		       argv[0], c);
+	    else
+	      fprintf (stderr, "%s: unrecognized option `-%c'\n", argv[0], c);
+	  }
+	return '?';
+      }
+    if (temp[1] == ':')
+      {
+	if (temp[2] == ':')
+	  {
+	    /* This is an option that accepts an argument optionally.  */
+	    if (*nextchar != '\0')
+	      {
+		optarg = nextchar;
+		optind++;
+	      }
+	    else
+	      optarg = 0;
+	    nextchar = NULL;
+	  }
+	else
+	  {
+	    /* This is an option that requires an argument.  */
+	    if (*nextchar != '\0')
+	      {
+		optarg = nextchar;
+		/* If we end this ARGV-element by taking the rest as an arg,
+		   we must advance to the next element now.  */
+		optind++;
+	      }
+	    else if (optind == argc)
+	      {
+		if (opterr)
+		  fprintf (stderr, "%s: option `-%c' requires an argument\n",
+			   argv[0], c);
+		c = '?';
+	      }
+	    else
+	      /* We already incremented `optind' once;
+		 increment it again when taking next ARGV-elt as argument.  */
+	      optarg = argv[optind++];
+	    nextchar = NULL;
+	  }
+      }
+    return c;
+  }
+}
+
+int
+getopt (argc, argv, optstring)
+     int argc;
+     char *const *argv;
+     const char *optstring;
+{
+  return _getopt_internal (argc, argv, optstring,
+			   (const struct option *) 0,
+			   (int *) 0,
+			   0);
+}
+
+#ifdef TEST
+
+/* Compile with -DTEST to make an executable for use in testing
+   the above definition of `getopt'.  */
+
+int
+main (argc, argv)
+     int argc;
+     char **argv;
+{
+  int c;
+  int digit_optind = 0;
+
+  while (1)
+    {
+      int this_option_optind = optind ? optind : 1;
+
+      c = getopt (argc, argv, "abc:d:0123456789");
+      if (c == EOF)
+	break;
+
+      switch (c)
+	{
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+	  if (digit_optind != 0 && digit_optind != this_option_optind)
+	    printf ("digits occur in two different argv-elements.\n");
+	  digit_optind = this_option_optind;
+	  printf ("option %c\n", c);
+	  break;
+
+	case 'a':
+	  printf ("option a\n");
+	  break;
+
+	case 'b':
+	  printf ("option b\n");
+	  break;
+
+	case 'c':
+	  printf ("option c with value `%s'\n", optarg);
+	  break;
+
+	case '?':
+	  break;
+
+	default:
+	  printf ("?? getopt returned character code 0%o ??\n", c);
+	}
+    }
+
+  if (optind < argc)
+    {
+      printf ("non-option ARGV-elements: ");
+      while (optind < argc)
+	printf ("%s ", argv[optind++]);
+      printf ("\n");
+    }
+
+  exit (0);
+}
+
+#endif /* TEST */
diff --git a/gnu/usr.bin/awk/getopt.h b/gnu/usr.bin/awk/getopt.h
new file mode 100644
index 000000000000..de027434f7cb
--- /dev/null
+++ b/gnu/usr.bin/awk/getopt.h
@@ -0,0 +1,128 @@
+/* Declarations for getopt.
+   Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Library General Public License as published
+   by the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#ifndef _GETOPT_H
+#define _GETOPT_H 1
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/* For communication from `getopt' to the caller.
+   When `getopt' finds an option that takes an argument,
+   the argument value is returned here.
+   Also, when `ordering' is RETURN_IN_ORDER,
+   each non-option ARGV-element is returned here.  */
+
+extern char *optarg;
+
+/* Index in ARGV of the next element to be scanned.
+   This is used for communication to and from the caller
+   and for communication between successive calls to `getopt'.
+
+   On entry to `getopt', zero means this is the first call; initialize.
+
+   When `getopt' returns EOF, this is the index of the first of the
+   non-option elements that the caller should itself scan.
+
+   Otherwise, `optind' communicates from one call to the next
+   how much of ARGV has been scanned so far.  */
+
+extern int optind;
+
+/* Callers store zero here to inhibit the error message `getopt' prints
+   for unrecognized options.  */
+
+extern int opterr;
+
+/* Describe the long-named options requested by the application.
+   The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
+   of `struct option' terminated by an element containing a name which is
+   zero.
+
+   The field `has_arg' is:
+   no_argument		(or 0) if the option does not take an argument,
+   required_argument	(or 1) if the option requires an argument,
+   optional_argument 	(or 2) if the option takes an optional argument.
+
+   If the field `flag' is not NULL, it points to a variable that is set
+   to the value given in the field `val' when the option is found, but
+   left unchanged if the option is not found.
+
+   To have a long-named option do something other than set an `int' to
+   a compiled-in constant, such as set a value from `optarg', set the
+   option's `flag' field to zero and its `val' field to a nonzero
+   value (the equivalent single-letter option character, if there is
+   one).  For long options that have a zero `flag' field, `getopt'
+   returns the contents of the `val' field.  */
+
+struct option
+{
+#if	__STDC__
+  const char *name;
+#else
+  char *name;
+#endif
+  /* has_arg can't be an enum because some compilers complain about
+     type mismatches in all the code that assumes it is an int.  */
+  int has_arg;
+  int *flag;
+  int val;
+};
+
+/* Names for the values of the `has_arg' field of `struct option'.  */
+
+enum _argtype
+{
+  no_argument,
+  required_argument,
+  optional_argument
+};
+
+#if __STDC__
+#if defined(__GNU_LIBRARY__)
+/* Many other libraries have conflicting prototypes for getopt, with
+   differences in the consts, in stdlib.h.  To avoid compilation
+   errors, only prototype getopt for the GNU C library.  */
+extern int getopt (int argc, char *const *argv, const char *shortopts);
+#else /* not __GNU_LIBRARY__ */
+extern int getopt ();
+#endif /* not __GNU_LIBRARY__ */
+extern int getopt_long (int argc, char *const *argv, const char *shortopts,
+		        const struct option *longopts, int *longind);
+extern int getopt_long_only (int argc, char *const *argv,
+			     const char *shortopts,
+		             const struct option *longopts, int *longind);
+
+/* Internal only.  Users should not call this directly.  */
+extern int _getopt_internal (int argc, char *const *argv,
+			     const char *shortopts,
+		             const struct option *longopts, int *longind,
+			     int long_only);
+#else /* not __STDC__ */
+extern int getopt ();
+extern int getopt_long ();
+extern int getopt_long_only ();
+
+extern int _getopt_internal ();
+#endif /* not __STDC__ */
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif /* _GETOPT_H */
diff --git a/gnu/usr.bin/awk/getopt1.c b/gnu/usr.bin/awk/getopt1.c
new file mode 100644
index 000000000000..e2127cd58d42
--- /dev/null
+++ b/gnu/usr.bin/awk/getopt1.c
@@ -0,0 +1,160 @@
+/* Getopt for GNU.
+   Copyright (C) 1987, 88, 89, 90, 91, 1992 Free Software Foundation, Inc.
+
+This file is part of the libiberty library.
+Libiberty is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public
+License as published by the Free Software Foundation; either
+version 2 of the License, or (at your option) any later version.
+
+Libiberty is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with libiberty; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#ifdef	LIBC
+/* For when compiled as part of the GNU C library.  */
+#include <ansidecl.h>
+#endif
+
+#include "getopt.h"
+
+#ifndef __STDC__
+#define const
+#endif
+
+#if defined(STDC_HEADERS) || defined(__GNU_LIBRARY__) || defined (LIBC)
+#include <stdlib.h>
+#else /* STDC_HEADERS or __GNU_LIBRARY__ */
+char *getenv ();
+#endif /* STDC_HEADERS or __GNU_LIBRARY__ */
+
+#if !defined (NULL)
+#define NULL 0
+#endif
+
+int
+getopt_long (argc, argv, options, long_options, opt_index)
+     int argc;
+     char *const *argv;
+     const char *options;
+     const struct option *long_options;
+     int *opt_index;
+{
+  return _getopt_internal (argc, argv, options, long_options, opt_index, 0);
+}
+
+/* Like getopt_long, but '-' as well as '--' can indicate a long option.
+   If an option that starts with '-' (not '--') doesn't match a long option,
+   but does match a short option, it is parsed as a short option
+   instead. */
+
+int 
+getopt_long_only (argc, argv, options, long_options, opt_index)
+     int argc;
+     char *const *argv;
+     const char *options;
+     const struct option *long_options;
+     int *opt_index;
+{
+  return _getopt_internal (argc, argv, options, long_options, opt_index, 1);
+}
+
+#ifdef TEST
+
+#include <stdio.h>
+
+int
+main (argc, argv)
+     int argc;
+     char **argv;
+{
+  int c;
+  int digit_optind = 0;
+
+  while (1)
+    {
+      int this_option_optind = optind ? optind : 1;
+      int option_index = 0;
+      static struct option long_options[] =
+      {
+	{"add", 1, 0, 0},
+	{"append", 0, 0, 0},
+	{"delete", 1, 0, 0},
+	{"verbose", 0, 0, 0},
+	{"create", 0, 0, 0},
+	{"file", 1, 0, 0},
+	{0, 0, 0, 0}
+      };
+
+      c = getopt_long (argc, argv, "abc:d:0123456789",
+		       long_options, &option_index);
+      if (c == EOF)
+	break;
+
+      switch (c)
+	{
+	case 0:
+	  printf ("option %s", long_options[option_index].name);
+	  if (optarg)
+	    printf (" with arg %s", optarg);
+	  printf ("\n");
+	  break;
+
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+	  if (digit_optind != 0 && digit_optind != this_option_optind)
+	    printf ("digits occur in two different argv-elements.\n");
+	  digit_optind = this_option_optind;
+	  printf ("option %c\n", c);
+	  break;
+
+	case 'a':
+	  printf ("option a\n");
+	  break;
+
+	case 'b':
+	  printf ("option b\n");
+	  break;
+
+	case 'c':
+	  printf ("option c with value `%s'\n", optarg);
+	  break;
+
+	case 'd':
+	  printf ("option d with value `%s'\n", optarg);
+	  break;
+
+	case '?':
+	  break;
+
+	default:
+	  printf ("?? getopt returned character code 0%o ??\n", c);
+	}
+    }
+
+  if (optind < argc)
+    {
+      printf ("non-option ARGV-elements: ");
+      while (optind < argc)
+	printf ("%s ", argv[optind++]);
+      printf ("\n");
+    }
+
+  exit (0);
+}
+
+#endif /* TEST */
diff --git a/gnu/usr.bin/awk/io.c b/gnu/usr.bin/awk/io.c
new file mode 100644
index 000000000000..7004aedd519d
--- /dev/null
+++ b/gnu/usr.bin/awk/io.c
@@ -0,0 +1,1207 @@
+/*
+ * io.c --- routines for dealing with input and output and records
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "awk.h"
+
+#ifndef O_RDONLY
+#include <fcntl.h>
+#endif
+
+#if !defined(S_ISDIR) && defined(S_IFDIR)
+#define	S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
+#endif
+
+#ifndef atarist
+#define INVALID_HANDLE (-1)
+#else
+#define INVALID_HANDLE  (__SMALLEST_VALID_HANDLE - 1)
+#endif
+
+#if defined(MSDOS) || defined(atarist)
+#define PIPES_SIMULATED
+#endif
+
+static IOBUF *nextfile P((int skipping));
+static int inrec P((IOBUF *iop));
+static int iop_close P((IOBUF *iop));
+struct redirect *redirect P((NODE *tree, int *errflg));
+static void close_one P((void));
+static int close_redir P((struct redirect *rp));
+#ifndef PIPES_SIMULATED
+static int wait_any P((int interesting));
+#endif
+static IOBUF *gawk_popen P((char *cmd, struct redirect *rp));
+static IOBUF *iop_open P((char *file, char *how));
+static int gawk_pclose P((struct redirect *rp));
+static int do_pathopen P((char *file));
+
+extern FILE	*fdopen();
+extern FILE	*popen();
+
+static struct redirect *red_head = NULL;
+
+extern int output_is_tty;
+extern NODE *ARGC_node;
+extern NODE *ARGV_node;
+extern NODE *ARGIND_node;
+extern NODE *ERRNO_node;
+extern NODE **fields_arr;
+
+static jmp_buf filebuf;		/* for do_nextfile() */
+
+/* do_nextfile --- implement gawk "next file" extension */
+
+void
+do_nextfile()
+{
+	(void) nextfile(1);
+	longjmp(filebuf, 1);
+}
+
+static IOBUF *
+nextfile(skipping)
+int skipping;
+{
+	static int i = 1;
+	static int files = 0;
+	NODE *arg;
+	int fd = INVALID_HANDLE;
+	static IOBUF *curfile = NULL;
+
+	if (skipping) {
+		if (curfile != NULL)
+			iop_close(curfile);
+		curfile = NULL;
+		return NULL;
+	}
+	if (curfile != NULL) {
+		if (curfile->cnt == EOF) {
+			(void) iop_close(curfile);
+			curfile = NULL;
+		} else
+			return curfile;
+	}
+	for (; i < (int) (ARGC_node->lnode->numbr); i++) {
+		arg = *assoc_lookup(ARGV_node, tmp_number((AWKNUM) i));
+		if (arg->stptr[0] == '\0')
+			continue;
+		arg->stptr[arg->stlen] = '\0';
+		if (! do_unix) {
+			ARGIND_node->var_value->numbr = i;
+			ARGIND_node->var_value->flags = NUM|NUMBER;
+		}
+		if (!arg_assign(arg->stptr)) {
+			files++;
+			curfile = iop_open(arg->stptr, "r");
+			if (curfile == NULL)
+				fatal("cannot open file `%s' for reading (%s)",
+					arg->stptr, strerror(errno));
+				/* NOTREACHED */
+			/* This is a kludge.  */
+			unref(FILENAME_node->var_value);
+			FILENAME_node->var_value =
+				dupnode(arg);
+			FNR = 0;
+			i++;
+			break;
+		}
+	}
+	if (files == 0) {
+		files++;
+		/* no args. -- use stdin */
+		/* FILENAME is init'ed to "-" */
+		/* FNR is init'ed to 0 */
+		curfile = iop_alloc(fileno(stdin));
+	}
+	return curfile;
+}
+
+void
+set_FNR()
+{
+	FNR = (int) FNR_node->var_value->numbr;
+}
+
+void
+set_NR()
+{
+	NR = (int) NR_node->var_value->numbr;
+}
+
+/*
+ * This reads in a record from the input file
+ */
+static int
+inrec(iop)
+IOBUF *iop;
+{
+	char *begin;
+	register int cnt;
+	int retval = 0;
+
+	cnt = get_a_record(&begin, iop, *RS, NULL);
+	if (cnt == EOF) {
+		cnt = 0;
+		retval = 1;
+	} else {
+		    NR += 1;
+		    FNR += 1;
+	}
+	set_record(begin, cnt, 1);
+
+	return retval;
+}
+
+static int
+iop_close(iop)
+IOBUF *iop;
+{
+	int ret;
+
+	if (iop == NULL)
+		return 0;
+	errno = 0;
+
+#ifdef _CRAY
+	/* Work around bug in UNICOS popen */
+	if (iop->fd < 3)
+		ret = 0;
+	else
+#endif
+	/* save these for re-use; don't free the storage */
+	if ((iop->flag & IOP_IS_INTERNAL) != 0) {
+		iop->off = iop->buf;
+		iop->end = iop->buf + strlen(iop->buf);
+		iop->cnt = 0;
+		iop->secsiz = 0;
+		return 0;
+	}
+
+	/* Don't close standard files or else crufty code elsewhere will lose */
+	if (iop->fd == fileno(stdin) ||
+	    iop->fd == fileno(stdout) ||
+	    iop->fd == fileno(stderr))
+		ret = 0;
+	else
+		ret = close(iop->fd);
+	if (ret == -1)
+		warning("close of fd %d failed (%s)", iop->fd, strerror(errno));
+	if ((iop->flag & IOP_NO_FREE) == 0) {
+		/*
+		 * be careful -- $0 may still reference the buffer even though
+		 * an explicit close is being done; in the future, maybe we
+		 * can do this a bit better
+		 */
+		if (iop->buf) {
+			if ((fields_arr[0]->stptr >= iop->buf)
+			    && (fields_arr[0]->stptr < iop->end)) {
+				NODE *t;
+	
+				t = make_string(fields_arr[0]->stptr,
+						fields_arr[0]->stlen);
+				unref(fields_arr[0]);
+				fields_arr [0] = t;
+				reset_record ();
+			}
+  			free(iop->buf);
+		}
+		free((char *)iop);
+	}
+	return ret == -1 ? 1 : 0;
+}
+
+void
+do_input()
+{
+	IOBUF *iop;
+	extern int exiting;
+
+	if (setjmp(filebuf) != 0) {
+	}
+	while ((iop = nextfile(0)) != NULL) {
+		if (inrec(iop) == 0)
+			while (interpret(expression_value) && inrec(iop) == 0)
+				;
+		if (exiting)
+			break;
+	}
+}
+
+/* Redirection for printf and print commands */
+struct redirect *
+redirect(tree, errflg)
+NODE *tree;
+int *errflg;
+{
+	register NODE *tmp;
+	register struct redirect *rp;
+	register char *str;
+	int tflag = 0;
+	int outflag = 0;
+	char *direction = "to";
+	char *mode;
+	int fd;
+	char *what = NULL;
+
+	switch (tree->type) {
+	case Node_redirect_append:
+		tflag = RED_APPEND;
+		/* FALL THROUGH */
+	case Node_redirect_output:
+		outflag = (RED_FILE|RED_WRITE);
+		tflag |= outflag;
+		if (tree->type == Node_redirect_output)
+			what = ">";
+		else
+			what = ">>";
+		break;
+	case Node_redirect_pipe:
+		tflag = (RED_PIPE|RED_WRITE);
+		what = "|";
+		break;
+	case Node_redirect_pipein:
+		tflag = (RED_PIPE|RED_READ);
+		what = "|";
+		break;
+	case Node_redirect_input:
+		tflag = (RED_FILE|RED_READ);
+		what = "<";
+		break;
+	default:
+		fatal ("invalid tree type %d in redirect()", tree->type);
+		break;
+	}
+	tmp = tree_eval(tree->subnode);
+	if (do_lint && ! (tmp->flags & STR))
+		warning("expression in `%s' redirection only has numeric value",
+			what);
+	tmp = force_string(tmp);
+	str = tmp->stptr;
+	if (str == NULL || *str == '\0')
+		fatal("expression for `%s' redirection has null string value",
+			what);
+	if (do_lint
+	    && (STREQN(str, "0", tmp->stlen) || STREQN(str, "1", tmp->stlen)))
+		warning("filename `%s' for `%s' redirection may be result of logical expression", str, what);
+	for (rp = red_head; rp != NULL; rp = rp->next)
+		if (strlen(rp->value) == tmp->stlen
+		    && STREQN(rp->value, str, tmp->stlen)
+		    && ((rp->flag & ~(RED_NOBUF|RED_EOF)) == tflag
+			|| (outflag
+			    && (rp->flag & (RED_FILE|RED_WRITE)) == outflag)))
+			break;
+	if (rp == NULL) {
+		emalloc(rp, struct redirect *, sizeof(struct redirect),
+			"redirect");
+		emalloc(str, char *, tmp->stlen+1, "redirect");
+		memcpy(str, tmp->stptr, tmp->stlen);
+		str[tmp->stlen] = '\0';
+		rp->value = str;
+		rp->flag = tflag;
+		rp->fp = NULL;
+		rp->iop = NULL;
+		rp->pid = 0;	/* unlikely that we're worried about init */
+		rp->status = 0;
+		/* maintain list in most-recently-used first order */
+		if (red_head)
+			red_head->prev = rp;
+		rp->prev = NULL;
+		rp->next = red_head;
+		red_head = rp;
+	}
+	while (rp->fp == NULL && rp->iop == NULL) {
+		if (rp->flag & RED_EOF)
+			/* encountered EOF on file or pipe -- must be cleared
+			 * by explicit close() before reading more
+			 */
+			return rp;
+		mode = NULL;
+		errno = 0;
+		switch (tree->type) {
+		case Node_redirect_output:
+			mode = "w";
+			if (rp->flag & RED_USED)
+				mode = "a";
+			break;
+		case Node_redirect_append:
+			mode = "a";
+			break;
+		case Node_redirect_pipe:
+			if ((rp->fp = popen(str, "w")) == NULL)
+				fatal("can't open pipe (\"%s\") for output (%s)",
+					str, strerror(errno));
+			rp->flag |= RED_NOBUF;
+			break;
+		case Node_redirect_pipein:
+			direction = "from";
+			if (gawk_popen(str, rp) == NULL)
+				fatal("can't open pipe (\"%s\") for input (%s)",
+					str, strerror(errno));
+			break;
+		case Node_redirect_input:
+			direction = "from";
+			rp->iop = iop_open(str, "r");
+			break;
+		default:
+			cant_happen();
+		}
+		if (mode != NULL) {
+			fd = devopen(str, mode);
+			if (fd > INVALID_HANDLE) {
+				if (fd == fileno(stdin))
+					rp->fp = stdin;
+				else if (fd == fileno(stdout))
+					rp->fp = stdout;
+				else if (fd == fileno(stderr))
+					rp->fp = stderr;
+				else	
+					rp->fp = fdopen(fd, mode);
+				if (isatty(fd))
+					rp->flag |= RED_NOBUF;
+			}
+		}
+		if (rp->fp == NULL && rp->iop == NULL) {
+			/* too many files open -- close one and try again */
+			if (errno == EMFILE)
+				close_one();
+			else {
+				/*
+				 * Some other reason for failure.
+				 *
+				 * On redirection of input from a file,
+				 * just return an error, so e.g. getline
+				 * can return -1.  For output to file,
+				 * complain. The shell will complain on
+				 * a bad command to a pipe.
+				 */
+				*errflg = errno;
+				if (tree->type == Node_redirect_output
+				    || tree->type == Node_redirect_append)
+					fatal("can't redirect %s `%s' (%s)",
+					    direction, str, strerror(errno));
+				else {
+					free_temp(tmp);
+					return NULL;
+				}
+			}
+		}
+	}
+	free_temp(tmp);
+	return rp;
+}
+
+static void
+close_one()
+{
+	register struct redirect *rp;
+	register struct redirect *rplast = NULL;
+
+	/* go to end of list first, to pick up least recently used entry */
+	for (rp = red_head; rp != NULL; rp = rp->next)
+		rplast = rp;
+	/* now work back up through the list */
+	for (rp = rplast; rp != NULL; rp = rp->prev)
+		if (rp->fp && (rp->flag & RED_FILE)) {
+			rp->flag |= RED_USED;
+			errno = 0;
+			if (fclose(rp->fp))
+				warning("close of \"%s\" failed (%s).",
+					rp->value, strerror(errno));
+			rp->fp = NULL;
+			break;
+		}
+	if (rp == NULL)
+		/* surely this is the only reason ??? */
+		fatal("too many pipes or input files open"); 
+}
+
+NODE *
+do_close(tree)
+NODE *tree;
+{
+	NODE *tmp;
+	register struct redirect *rp;
+
+	tmp = force_string(tree_eval(tree->subnode));
+	for (rp = red_head; rp != NULL; rp = rp->next) {
+		if (strlen(rp->value) == tmp->stlen
+		    && STREQN(rp->value, tmp->stptr, tmp->stlen))
+			break;
+	}
+	free_temp(tmp);
+	if (rp == NULL) /* no match */
+		return tmp_number((AWKNUM) 0.0);
+	fflush(stdout);	/* synchronize regular output */
+	tmp = tmp_number((AWKNUM)close_redir(rp));
+	rp = NULL;
+	return tmp;
+}
+
+static int
+close_redir(rp)
+register struct redirect *rp;
+{
+	int status = 0;
+
+	if (rp == NULL)
+		return 0;
+	if (rp->fp == stdout || rp->fp == stderr)
+		return 0;
+	errno = 0;
+	if ((rp->flag & (RED_PIPE|RED_WRITE)) == (RED_PIPE|RED_WRITE))
+		status = pclose(rp->fp);
+	else if (rp->fp)
+		status = fclose(rp->fp);
+	else if (rp->iop) {
+		if (rp->flag & RED_PIPE)
+			status = gawk_pclose(rp);
+		else {
+			status = iop_close(rp->iop);
+			rp->iop = NULL;
+		}
+	}
+	/* SVR4 awk checks and warns about status of close */
+	if (status) {
+		char *s = strerror(errno);
+
+		warning("failure status (%d) on %s close of \"%s\" (%s).",
+			status,
+			(rp->flag & RED_PIPE) ? "pipe" :
+			"file", rp->value, s);
+
+		if (! do_unix) {
+			/* set ERRNO too so that program can get at it */
+			unref(ERRNO_node->var_value);
+			ERRNO_node->var_value = make_string(s, strlen(s));
+		}
+	}
+	if (rp->next)
+		rp->next->prev = rp->prev;
+	if (rp->prev)
+		rp->prev->next = rp->next;
+	else
+		red_head = rp->next;
+	free(rp->value);
+	free((char *)rp);
+	return status;
+}
+
+int
+flush_io ()
+{
+	register struct redirect *rp;
+	int status = 0;
+
+	errno = 0;
+	if (fflush(stdout)) {
+		warning("error writing standard output (%s).", strerror(errno));
+		status++;
+	}
+	if (fflush(stderr)) {
+		warning("error writing standard error (%s).", strerror(errno));
+		status++;
+	}
+	for (rp = red_head; rp != NULL; rp = rp->next)
+		/* flush both files and pipes, what the heck */
+		if ((rp->flag & RED_WRITE) && rp->fp != NULL) {
+			if (fflush(rp->fp)) {
+				warning("%s flush of \"%s\" failed (%s).",
+				    (rp->flag  & RED_PIPE) ? "pipe" :
+				    "file", rp->value, strerror(errno));
+				status++;
+			}
+		}
+	return status;
+}
+
+int
+close_io ()
+{
+	register struct redirect *rp;
+	register struct redirect *next;
+	int status = 0;
+
+	errno = 0;
+	if (fclose(stdout)) {
+		warning("error writing standard output (%s).", strerror(errno));
+		status++;
+	}
+	if (fclose(stderr)) {
+		warning("error writing standard error (%s).", strerror(errno));
+		status++;
+	}
+	for (rp = red_head; rp != NULL; rp = next) {
+		next = rp->next;
+		if (close_redir(rp))
+			status++;
+		rp = NULL;
+	}
+	return status;
+}
+
+/* str2mode --- convert a string mode to an integer mode */
+
+static int
+str2mode(mode)
+char *mode;
+{
+	int ret;
+
+	switch(mode[0]) {
+	case 'r':
+		ret = O_RDONLY;
+		break;
+
+	case 'w':
+		ret = O_WRONLY|O_CREAT|O_TRUNC;
+		break;
+
+	case 'a':
+		ret = O_WRONLY|O_APPEND|O_CREAT;
+		break;
+	default:
+		cant_happen();
+	}
+	return ret;
+}
+
+/* devopen --- handle /dev/std{in,out,err}, /dev/fd/N, regular files */
+
+/*
+ * This separate version is still needed for output, since file and pipe
+ * output is done with stdio. iop_open() handles input with IOBUFs of
+ * more "special" files.  Those files are not handled here since it makes
+ * no sense to use them for output.
+ */
+
+int
+devopen(name, mode)
+char *name, *mode;
+{
+	int openfd = INVALID_HANDLE;
+	char *cp, *ptr;
+	int flag = 0;
+	struct stat buf;
+	extern double strtod();
+
+	flag = str2mode(mode);
+
+	if (do_unix)
+		goto strictopen;
+
+#ifdef VMS
+	if ((openfd = vms_devopen(name, flag)) >= 0)
+		return openfd;
+#endif /* VMS */
+
+	if (STREQ(name, "-"))
+		openfd = fileno(stdin);
+	else if (STREQN(name, "/dev/", 5) && stat(name, &buf) == -1) {
+		cp = name + 5;
+		
+		if (STREQ(cp, "stdin") && (flag & O_RDONLY) == O_RDONLY)
+			openfd = fileno(stdin);
+		else if (STREQ(cp, "stdout") && (flag & O_WRONLY) == O_WRONLY)
+			openfd = fileno(stdout);
+		else if (STREQ(cp, "stderr") && (flag & O_WRONLY) == O_WRONLY)
+			openfd = fileno(stderr);
+		else if (STREQN(cp, "fd/", 3)) {
+			cp += 3;
+			openfd = (int)strtod(cp, &ptr);
+			if (openfd <= INVALID_HANDLE || ptr == cp)
+				openfd = INVALID_HANDLE;
+		}
+	}
+
+strictopen:
+	if (openfd == INVALID_HANDLE)
+		openfd = open(name, flag, 0666);
+	if (openfd != INVALID_HANDLE && fstat(openfd, &buf) > 0) 
+		if (S_ISDIR(buf.st_mode))
+			fatal("file `%s' is a directory", name);
+	return openfd;
+}
+
+
+/* spec_setup --- setup an IOBUF for a special internal file */
+
+void
+spec_setup(iop, len, allocate)
+IOBUF *iop;
+int len;
+int allocate;
+{
+	char *cp;
+
+	if (allocate) {
+		emalloc(cp, char *, len+2, "spec_setup");
+		iop->buf = cp;
+	} else {
+		len = strlen(iop->buf);
+		iop->buf[len++] = '\n';	/* get_a_record clobbered it */
+		iop->buf[len] = '\0';	/* just in case */
+	}
+	iop->off = iop->buf;
+	iop->cnt = 0;
+	iop->secsiz = 0;
+	iop->size = len;
+	iop->end = iop->buf + len;
+	iop->fd = -1;
+	iop->flag = IOP_IS_INTERNAL;
+}
+
+/* specfdopen --- open a fd special file */
+
+int
+specfdopen(iop, name, mode)
+IOBUF *iop;
+char *name, *mode;
+{
+	int fd;
+	IOBUF *tp;
+
+	fd = devopen(name, mode);
+	if (fd == INVALID_HANDLE)
+		return INVALID_HANDLE;
+	tp = iop_alloc(fd);
+	if (tp == NULL)
+		return INVALID_HANDLE;
+	*iop = *tp;
+	iop->flag |= IOP_NO_FREE;
+	free(tp);
+	return 0;
+}
+
+/* pidopen --- "open" /dev/pid, /dev/ppid, and /dev/pgrpid */
+
+int
+pidopen(iop, name, mode)
+IOBUF *iop;
+char *name, *mode;
+{
+	char tbuf[BUFSIZ];
+	int i;
+
+	if (name[6] == 'g')
+/* following #if will improve in 2.16 */
+#if defined(__svr4__) || defined(i860) || defined(_AIX) || defined(BSD4_4) || defined(__386BSD__)
+		sprintf(tbuf, "%d\n", getpgrp());
+#else
+		sprintf(tbuf, "%d\n", getpgrp(getpid()));
+#endif
+	else if (name[6] == 'i')
+		sprintf(tbuf, "%d\n", getpid());
+	else
+		sprintf(tbuf, "%d\n", getppid());
+	i = strlen(tbuf);
+	spec_setup(iop, i, 1);
+	strcpy(iop->buf, tbuf);
+	return 0;
+}
+
+/* useropen --- "open" /dev/user */
+
+/*
+ * /dev/user creates a record as follows:
+ *	$1 = getuid()
+ *	$2 = geteuid()
+ *	$3 = getgid()
+ *	$4 = getegid()
+ * If multiple groups are supported, the $5 through $NF are the
+ * supplementary group set.
+ */
+
+int
+useropen(iop, name, mode)
+IOBUF *iop;
+char *name, *mode;
+{
+	char tbuf[BUFSIZ], *cp;
+	int i;
+#if defined(NGROUPS_MAX) && NGROUPS_MAX > 0
+	int groupset[NGROUPS_MAX];
+	int ngroups;
+#endif
+
+	sprintf(tbuf, "%d %d %d %d", getuid(), geteuid(), getgid(), getegid());
+
+	cp = tbuf + strlen(tbuf);
+#if defined(NGROUPS_MAX) && NGROUPS_MAX > 0
+	ngroups = getgroups(NGROUPS_MAX, groupset);
+	if (ngroups == -1)
+		fatal("could not find groups: %s", strerror(errno));
+
+	for (i = 0; i < ngroups; i++) {
+		*cp++ = ' ';
+		sprintf(cp, "%d", groupset[i]);
+		cp += strlen(cp);
+	}
+#endif
+	*cp++ = '\n';
+	*cp++ = '\0';
+
+
+	i = strlen(tbuf);
+	spec_setup(iop, i, 1);
+	strcpy(iop->buf, tbuf);
+	return 0;
+}
+
+/* iop_open --- handle special and regular files for input */
+
+static IOBUF *
+iop_open(name, mode)
+char *name, *mode;
+{
+	int openfd = INVALID_HANDLE;
+	char *cp, *ptr;
+	int flag = 0;
+	int i;
+	struct stat buf;
+	IOBUF *iop;
+	static struct internal {
+		char *name;
+		int compare;
+		int (*fp)();
+		IOBUF iob;
+	} table[] = {
+		{ "/dev/fd/",		8,	specfdopen },
+		{ "/dev/stdin",		10,	specfdopen },
+		{ "/dev/stdout",	11,	specfdopen },
+		{ "/dev/stderr",	11,	specfdopen },
+		{ "/dev/pid",		8,	pidopen },
+		{ "/dev/ppid",		9,	pidopen },
+		{ "/dev/pgrpid",	11,	pidopen },
+		{ "/dev/user",		9,	useropen },
+	};
+	int devcount = sizeof(table) / sizeof(table[0]);
+
+	flag = str2mode(mode);
+
+	if (do_unix)
+		goto strictopen;
+
+	if (STREQ(name, "-"))
+		openfd = fileno(stdin);
+	else if (STREQN(name, "/dev/", 5) && stat(name, &buf) == -1) {
+		int i;
+
+		for (i = 0; i < devcount; i++) {
+			if (STREQN(name, table[i].name, table[i].compare)) {
+				IOBUF *iop = & table[i].iob;
+
+				if (iop->buf != NULL) {
+					spec_setup(iop, 0, 0);
+					return iop;
+				} else if ((*table[i].fp)(iop, name, mode) == 0)
+					return iop;
+				else {
+					warning("could not open %s, mode `%s'",
+						name, mode);
+					return NULL;
+				}
+			}
+		}
+	}
+
+strictopen:
+	if (openfd == INVALID_HANDLE)
+		openfd = open(name, flag, 0666);
+	if (openfd != INVALID_HANDLE && fstat(openfd, &buf) > 0) 
+		if ((buf.st_mode & S_IFMT) == S_IFDIR)
+			fatal("file `%s' is a directory", name);
+	iop = iop_alloc(openfd);
+	return iop;
+}
+
+#ifndef PIPES_SIMULATED
+	/* real pipes */
+static int
+wait_any(interesting)
+int interesting;	/* pid of interest, if any */
+{
+	SIGTYPE (*hstat)(), (*istat)(), (*qstat)();
+	int pid;
+	int status = 0;
+	struct redirect *redp;
+	extern int errno;
+
+	hstat = signal(SIGHUP, SIG_IGN);
+	istat = signal(SIGINT, SIG_IGN);
+	qstat = signal(SIGQUIT, SIG_IGN);
+	for (;;) {
+#ifdef NeXT
+		pid = wait((union wait *)&status);
+#else
+		pid = wait(&status);
+#endif /* NeXT */
+		if (interesting && pid == interesting) {
+			break;
+		} else if (pid != -1) {
+			for (redp = red_head; redp != NULL; redp = redp->next)
+				if (pid == redp->pid) {
+					redp->pid = -1;
+					redp->status = status;
+					if (redp->fp) {
+						pclose(redp->fp);
+						redp->fp = 0;
+					}
+					if (redp->iop) {
+						(void) iop_close(redp->iop);
+						redp->iop = 0;
+					}
+					break;
+				}
+		}
+		if (pid == -1 && errno == ECHILD)
+			break;
+	}
+	signal(SIGHUP, hstat);
+	signal(SIGINT, istat);
+	signal(SIGQUIT, qstat);
+	return(status);
+}
+
+static IOBUF *
+gawk_popen(cmd, rp)
+char *cmd;
+struct redirect *rp;
+{
+	int p[2];
+	register int pid;
+
+	/* used to wait for any children to synchronize input and output,
+	 * but this could cause gawk to hang when it is started in a pipeline
+	 * and thus has a child process feeding it input (shell dependant)
+	 */
+	/*(void) wait_any(0);*/	/* wait for outstanding processes */
+
+	if (pipe(p) < 0)
+		fatal("cannot open pipe \"%s\" (%s)", cmd, strerror(errno));
+	if ((pid = fork()) == 0) {
+		if (close(1) == -1)
+			fatal("close of stdout in child failed (%s)",
+				strerror(errno));
+		if (dup(p[1]) != 1)
+			fatal("dup of pipe failed (%s)", strerror(errno));
+		if (close(p[0]) == -1 || close(p[1]) == -1)
+			fatal("close of pipe failed (%s)", strerror(errno));
+		if (close(0) == -1)
+			fatal("close of stdin in child failed (%s)",
+				strerror(errno));
+		execl("/bin/sh", "sh", "-c", cmd, 0);
+		_exit(127);
+	}
+	if (pid == -1)
+		fatal("cannot fork for \"%s\" (%s)", cmd, strerror(errno));
+	rp->pid = pid;
+	if (close(p[1]) == -1)
+		fatal("close of pipe failed (%s)", strerror(errno));
+	return (rp->iop = iop_alloc(p[0]));
+}
+
+static int
+gawk_pclose(rp)
+struct redirect *rp;
+{
+	(void) iop_close(rp->iop);
+	rp->iop = NULL;
+
+	/* process previously found, return stored status */
+	if (rp->pid == -1)
+		return (rp->status >> 8) & 0xFF;
+	rp->status = wait_any(rp->pid);
+	rp->pid = -1;
+	return (rp->status >> 8) & 0xFF;
+}
+
+#else	/* PIPES_SIMULATED */
+	/* use temporary file rather than pipe */
+
+#ifdef VMS
+static IOBUF *
+gawk_popen(cmd, rp)
+char *cmd;
+struct redirect *rp;
+{
+	FILE *current;
+
+	if ((current = popen(cmd, "r")) == NULL)
+		return NULL;
+	return (rp->iop = iop_alloc(fileno(current)));
+}
+
+static int
+gawk_pclose(rp)
+struct redirect *rp;
+{
+	int rval, aval, fd = rp->iop->fd;
+	FILE *kludge = fdopen(fd, "r"); /* pclose needs FILE* w/ right fileno */
+
+	rp->iop->fd = dup(fd);	  /* kludge to allow close() + pclose() */
+	rval = iop_close(rp->iop);
+	rp->iop = NULL;
+	aval = pclose(kludge);
+	return (rval < 0 ? rval : aval);
+}
+#else	/* VMS */
+
+static
+struct {
+	char *command;
+	char *name;
+} pipes[_NFILE];
+
+static IOBUF *
+gawk_popen(cmd, rp)
+char *cmd;
+struct redirect *rp;
+{
+	extern char *strdup(const char *);
+	int current;
+	char *name;
+	static char cmdbuf[256];
+
+	/* get a name to use.  */
+	if ((name = tempnam(".", "pip")) == NULL)
+		return NULL;
+	sprintf(cmdbuf,"%s > %s", cmd, name);
+	system(cmdbuf);
+	if ((current = open(name,O_RDONLY)) == INVALID_HANDLE)
+		return NULL;
+	pipes[current].name = name;
+	pipes[current].command = strdup(cmd);
+	rp->iop = iop_alloc(current);
+	return (rp->iop = iop_alloc(current));
+}
+
+static int
+gawk_pclose(rp)
+struct redirect *rp;
+{
+	int cur = rp->iop->fd;
+	int rval;
+
+	rval = iop_close(rp->iop);
+	rp->iop = NULL;
+
+	/* check for an open file  */
+	if (pipes[cur].name == NULL)
+		return -1;
+	unlink(pipes[cur].name);
+	free(pipes[cur].name);
+	pipes[cur].name = NULL;
+	free(pipes[cur].command);
+	return rval;
+}
+#endif	/* VMS */
+
+#endif	/* PIPES_SIMULATED */
+
+NODE *
+do_getline(tree)
+NODE *tree;
+{
+	struct redirect *rp = NULL;
+	IOBUF *iop;
+	int cnt = EOF;
+	char *s = NULL;
+	int errcode;
+
+	while (cnt == EOF) {
+		if (tree->rnode == NULL) {	 /* no redirection */
+			iop = nextfile(0);
+			if (iop == NULL)		/* end of input */
+				return tmp_number((AWKNUM) 0.0);
+		} else {
+			int redir_error = 0;
+
+			rp = redirect(tree->rnode, &redir_error);
+			if (rp == NULL && redir_error) { /* failed redirect */
+				if (! do_unix) {
+					char *s = strerror(redir_error);
+
+					unref(ERRNO_node->var_value);
+					ERRNO_node->var_value =
+						make_string(s, strlen(s));
+				}
+				return tmp_number((AWKNUM) -1.0);
+			}
+			iop = rp->iop;
+			if (iop == NULL)		/* end of input */
+				return tmp_number((AWKNUM) 0.0);
+		}
+		errcode = 0;
+		cnt = get_a_record(&s, iop, *RS, & errcode);
+		if (! do_unix && errcode != 0) {
+			char *s = strerror(errcode);
+
+			unref(ERRNO_node->var_value);
+			ERRNO_node->var_value = make_string(s, strlen(s));
+			return tmp_number((AWKNUM) -1.0);
+		}
+		if (cnt == EOF) {
+			if (rp) {
+				/*
+				 * Don't do iop_close() here if we are
+				 * reading from a pipe; otherwise
+				 * gawk_pclose will not be called.
+				 */
+				if (!(rp->flag & RED_PIPE)) {
+					(void) iop_close(iop);
+					rp->iop = NULL;
+				}
+				rp->flag |= RED_EOF;	/* sticky EOF */
+				return tmp_number((AWKNUM) 0.0);
+			} else
+				continue;	/* try another file */
+		}
+		if (!rp) {
+			NR += 1;
+			FNR += 1;
+		}
+		if (tree->lnode == NULL)	/* no optional var. */
+			set_record(s, cnt, 1);
+		else {			/* assignment to variable */
+			Func_ptr after_assign = NULL;
+			NODE **lhs;
+
+			lhs = get_lhs(tree->lnode, &after_assign);
+			unref(*lhs);
+			*lhs = make_string(s, strlen(s));
+			(*lhs)->flags |= MAYBE_NUM;
+			/* we may have to regenerate $0 here! */
+			if (after_assign)
+				(*after_assign)();
+		}
+	}
+	return tmp_number((AWKNUM) 1.0);
+}
+
+int
+pathopen (file)
+char *file;
+{
+	int fd = do_pathopen(file);
+
+#ifdef DEFAULT_FILETYPE
+	if (! do_unix && fd <= INVALID_HANDLE) {
+		char *file_awk;
+		int save = errno;
+#ifdef VMS
+		int vms_save = vaxc$errno;
+#endif
+
+		/* append ".awk" and try again */
+		emalloc(file_awk, char *, strlen(file) +
+			sizeof(DEFAULT_FILETYPE) + 1, "pathopen");
+		sprintf(file_awk, "%s%s", file, DEFAULT_FILETYPE);
+		fd = do_pathopen(file_awk);
+		free(file_awk);
+		if (fd <= INVALID_HANDLE) {
+			errno = save;
+#ifdef VMS
+			vaxc$errno = vms_save;
+#endif
+		}
+	}
+#endif	/*DEFAULT_FILETYPE*/
+
+	return fd;
+}
+
+static int
+do_pathopen (file)
+char *file;
+{
+	static char *savepath = DEFPATH;	/* defined in config.h */
+	static int first = 1;
+	char *awkpath, *cp;
+	char trypath[BUFSIZ];
+	int fd;
+
+	if (STREQ(file, "-"))
+		return (0);
+
+	if (do_unix)
+		return (devopen(file, "r"));
+
+	if (first) {
+		first = 0;
+		if ((awkpath = getenv ("AWKPATH")) != NULL && *awkpath)
+			savepath = awkpath;	/* used for restarting */
+	}
+	awkpath = savepath;
+
+	/* some kind of path name, no search */
+#ifdef VMS	/* (strchr not equal implies either or both not NULL) */
+	if (strchr(file, ':') != strchr(file, ']')
+	 || strchr(file, '>') != strchr(file, '/'))
+#else /*!VMS*/
+#ifdef MSDOS
+	if (strchr(file, '/') != strchr(file, '\\')
+	 || strchr(file, ':') != NULL)
+#else
+	if (strchr(file, '/') != NULL)
+#endif	/*MSDOS*/
+#endif	/*VMS*/
+		return (devopen(file, "r"));
+
+	do {
+		trypath[0] = '\0';
+		/* this should take into account limits on size of trypath */
+		for (cp = trypath; *awkpath && *awkpath != ENVSEP; )
+			*cp++ = *awkpath++;
+
+		if (cp != trypath) {	/* nun-null element in path */
+			/* add directory punctuation only if needed */
+#ifdef VMS
+			if (strchr(":]>/", *(cp-1)) == NULL)
+#else
+#ifdef MSDOS
+			if (strchr(":\\/", *(cp-1)) == NULL)
+#else
+			if (*(cp-1) != '/')
+#endif
+#endif
+				*cp++ = '/';
+			/* append filename */
+			strcpy (cp, file);
+		} else
+			strcpy (trypath, file);
+		if ((fd = devopen(trypath, "r")) >= 0)
+			return (fd);
+
+		/* no luck, keep going */
+		if(*awkpath == ENVSEP && awkpath[1] != '\0')
+			awkpath++;	/* skip colon */
+	} while (*awkpath);
+	/*
+	 * You might have one of the awk
+	 * paths defined, WITHOUT the current working directory in it.
+	 * Therefore try to open the file in the current directory.
+	 */
+	return (devopen(file, "r"));
+}
diff --git a/gnu/usr.bin/awk/iop.c b/gnu/usr.bin/awk/iop.c
new file mode 100644
index 000000000000..0d7af1213db6
--- /dev/null
+++ b/gnu/usr.bin/awk/iop.c
@@ -0,0 +1,318 @@
+/*
+ * iop.c - do i/o related things.
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "awk.h"
+
+#ifndef atarist
+#define INVALID_HANDLE (-1)
+#else
+#include <stddef.h>
+#include <fcntl.h>
+#define INVALID_HANDLE  (__SMALLEST_VALID_HANDLE - 1)
+#endif  /* atarist */
+
+
+#ifdef TEST
+int bufsize = 8192;
+
+void
+fatal(s)
+char *s;
+{
+	printf("%s\n", s);
+	exit(1);
+}
+#endif
+
+int
+optimal_bufsize(fd)
+int fd;
+{
+	struct stat stb;
+
+#ifdef VMS
+	/*
+	 * These values correspond with the RMS multi-block count used by
+	 * vms_open() in vms/vms_misc.c.
+	 */
+	if (isatty(fd) > 0)
+		return BUFSIZ;
+	else if (fstat(fd, &stb) < 0)
+		return 8*512;	/* conservative in case of DECnet access */
+	else
+		return 24*512;
+
+#else
+	/*
+	 * System V doesn't have the file system block size in the
+	 * stat structure. So we have to make some sort of reasonable
+	 * guess. We use stdio's BUFSIZ, since that is what it was
+	 * meant for in the first place.
+	 */
+#ifdef BLKSIZE_MISSING
+#define	DEFBLKSIZE	BUFSIZ
+#else
+#define DEFBLKSIZE	(stb.st_blksize ? stb.st_blksize : BUFSIZ)
+#endif
+
+#ifdef TEST
+	return bufsize;
+#else
+#ifndef atarist
+	if (isatty(fd))
+#else
+	/*
+	 * On ST redirected stdin does not have a name attached
+	 * (this could be hard to do to) and fstat would fail
+	 */
+	if (0 == fd || isatty(fd))
+#endif  /*atarist */
+		return BUFSIZ;
+#ifndef BLKSIZE_MISSING
+	/* VMS POSIX 1.0: st_blksize is never assigned a value, so zero it */
+	stb.st_blksize = 0;
+#endif
+	if (fstat(fd, &stb) == -1)
+		fatal("can't stat fd %d (%s)", fd, strerror(errno));
+	if (lseek(fd, (off_t)0, 0) == -1)
+		return DEFBLKSIZE;
+	return ((int) (stb.st_size < DEFBLKSIZE ? stb.st_size : DEFBLKSIZE));
+#endif	/*! TEST */
+#endif	/*! VMS */
+}
+
+IOBUF *
+iop_alloc(fd)
+int fd;
+{
+	IOBUF *iop;
+
+	if (fd == INVALID_HANDLE)
+		return NULL;
+	emalloc(iop, IOBUF *, sizeof(IOBUF), "iop_alloc");
+	iop->flag = 0;
+	if (isatty(fd))
+		iop->flag |= IOP_IS_TTY;
+	iop->size = optimal_bufsize(fd);
+	iop->secsiz = -2;
+	errno = 0;
+	iop->fd = fd;
+	iop->off = iop->buf = NULL;
+	iop->cnt = 0;
+	return iop;
+}
+
+/*
+ * Get the next record.  Uses a "split buffer" where the latter part is
+ * the normal read buffer and the head part is an "overflow" area that is used
+ * when a record spans the end of the normal buffer, in which case the first
+ * part of the record is copied into the overflow area just before the
+ * normal buffer.  Thus, the eventual full record can be returned as a
+ * contiguous area of memory with a minimum of copying.  The overflow area
+ * is expanded as needed, so that records are unlimited in length.
+ * We also mark both the end of the buffer and the end of the read() with
+ * a sentinel character (the current record separator) so that the inside
+ * loop can run as a single test.
+ */
+int
+get_a_record(out, iop, grRS, errcode)
+char **out;
+IOBUF *iop;
+register int grRS;
+int *errcode;
+{
+	register char *bp = iop->off;
+	char *bufend;
+	char *start = iop->off;			/* beginning of record */
+	int saw_newline;
+	char rs;
+	int eat_whitespace;
+
+	if (iop->cnt == EOF)	/* previous read hit EOF */
+		return EOF;
+
+	if (grRS == 0) {	/* special case:  grRS == "" */
+		rs = '\n';
+		eat_whitespace = 0;
+		saw_newline = 0;
+	} else
+		rs = (char) grRS;
+
+	/* set up sentinel */
+	if (iop->buf) {
+		bufend = iop->buf + iop->size + iop->secsiz;
+		*bufend = rs;
+	} else
+		bufend = NULL;
+
+	for (;;) {	/* break on end of record, read error or EOF */
+
+		/* Following code is entered on the first call of this routine
+		 * for a new iop, or when we scan to the end of the buffer.
+		 * In the latter case, we copy the current partial record to
+		 * the space preceding the normal read buffer.  If necessary,
+		 * we expand this space.  This is done so that we can return
+		 * the record as a contiguous area of memory.
+		 */
+		if ((iop->flag & IOP_IS_INTERNAL) == 0 && bp >= bufend) {
+			char *oldbuf = NULL;
+			char *oldsplit = iop->buf + iop->secsiz;
+			long len;	/* record length so far */
+
+			if ((iop->flag & IOP_IS_INTERNAL) != 0)
+				cant_happen();
+
+			len = bp - start;
+			if (len > iop->secsiz) {
+				/* expand secondary buffer */
+				if (iop->secsiz == -2)
+					iop->secsiz = 256;
+				while (len > iop->secsiz)
+					iop->secsiz *= 2;
+				oldbuf = iop->buf;
+				emalloc(iop->buf, char *,
+				    iop->size+iop->secsiz+2, "get_a_record");
+				bufend = iop->buf + iop->size + iop->secsiz;
+				*bufend = rs;
+			}
+			if (len > 0) {
+				char *newsplit = iop->buf + iop->secsiz;
+
+				if (start < oldsplit) {
+					memcpy(newsplit - len, start,
+							oldsplit - start);
+					memcpy(newsplit - (bp - oldsplit),
+							oldsplit, bp - oldsplit);
+				} else
+					memcpy(newsplit - len, start, len);
+			}
+			bp = iop->end = iop->off = iop->buf + iop->secsiz;
+			start = bp - len;
+			if (oldbuf) {
+				free(oldbuf);
+				oldbuf = NULL;
+			}
+		}
+		/* Following code is entered whenever we have no more data to
+		 * scan.  In most cases this will read into the beginning of
+		 * the main buffer, but in some cases (terminal, pipe etc.)
+		 * we may be doing smallish reads into more advanced positions.
+		 */
+		if (bp >= iop->end) {
+			if ((iop->flag & IOP_IS_INTERNAL) != 0) {
+				iop->cnt = EOF;
+				break;
+			}
+			iop->cnt = read(iop->fd, iop->end, bufend - iop->end);
+			if (iop->cnt == -1) {
+				if (! do_unix && errcode != NULL) {
+					*errcode = errno;
+					iop->cnt = EOF;
+					break;
+				} else
+					fatal("error reading input: %s",
+						strerror(errno));
+			} else if (iop->cnt == 0) {
+				iop->cnt = EOF;
+				break;
+			}
+			iop->end += iop->cnt;
+			*iop->end = rs;
+		}
+		if (grRS == 0) {
+			extern int default_FS;
+
+			if (default_FS && (bp == start || eat_whitespace)) {
+				while (bp < iop->end && isspace(*bp))
+					bp++;
+				if (bp == iop->end) {
+					eat_whitespace = 1;
+					continue;
+				} else
+					eat_whitespace = 0;
+			}
+			if (saw_newline && *bp == rs) {
+				bp++;
+				break;
+			}
+			saw_newline = 0;
+		}
+
+		while (*bp++ != rs)
+			;
+
+		if (bp <= iop->end) {
+			if (grRS == 0)
+				saw_newline = 1;
+			else
+				break;
+		} else
+			bp--;
+
+		if ((iop->flag & IOP_IS_INTERNAL) != 0)
+			iop->cnt = bp - start;
+	}
+	if (iop->cnt == EOF
+	    && (((iop->flag & IOP_IS_INTERNAL) != 0) || start == bp))
+		return EOF;
+
+	iop->off = bp;
+	bp--;
+	if (*bp != rs)
+		bp++;
+	*bp = '\0';
+	if (grRS == 0) {
+		if (*--bp == rs)
+			*bp = '\0';
+		else
+			bp++;
+	}
+
+	*out = start;
+	return bp - start;
+}
+
+#ifdef TEST
+main(argc, argv)
+int argc;
+char *argv[];
+{
+	IOBUF *iop;
+	char *out;
+	int cnt;
+	char rs[2];
+
+	rs[0] = 0;
+	if (argc > 1)
+		bufsize = atoi(argv[1]);
+	if (argc > 2)
+		rs[0] = *argv[2];
+	iop = iop_alloc(0);
+	while ((cnt = get_a_record(&out, iop, rs[0], NULL)) > 0) {
+		fwrite(out, 1, cnt, stdout);
+		fwrite(rs, 1, 1, stdout);
+	}
+}
+#endif
diff --git a/gnu/usr.bin/awk/main.c b/gnu/usr.bin/awk/main.c
new file mode 100644
index 000000000000..77d0bf74e143
--- /dev/null
+++ b/gnu/usr.bin/awk/main.c
@@ -0,0 +1,731 @@
+/*
+ * main.c -- Expression tree constructors and main program for gawk. 
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "getopt.h"
+#include "awk.h"
+#include "patchlevel.h"
+
+static void usage P((int exitval));
+static void copyleft P((void));
+static void cmdline_fs P((char *str));
+static void init_args P((int argc0, int argc, char *argv0, char **argv));
+static void init_vars P((void));
+static void pre_assign P((char *v));
+SIGTYPE catchsig P((int sig, int code));
+static void gawk_option P((char *optstr));
+static void nostalgia P((void));
+static void version P((void));
+char *gawk_name P((char *filespec));
+
+#ifdef MSDOS
+extern int isatty P((int));
+#endif
+
+extern void resetup P((void));
+
+/* These nodes store all the special variables AWK uses */
+NODE *FS_node, *NF_node, *RS_node, *NR_node;
+NODE *FILENAME_node, *OFS_node, *ORS_node, *OFMT_node;
+NODE *CONVFMT_node;
+NODE *ERRNO_node;
+NODE *FNR_node, *RLENGTH_node, *RSTART_node, *SUBSEP_node;
+NODE *ENVIRON_node, *IGNORECASE_node;
+NODE *ARGC_node, *ARGV_node, *ARGIND_node;
+NODE *FIELDWIDTHS_node;
+
+int NF;
+int NR;
+int FNR;
+int IGNORECASE;
+char *RS;
+char *OFS;
+char *ORS;
+char *OFMT;
+char *CONVFMT;
+
+/*
+ * The parse tree and field nodes are stored here.  Parse_end is a dummy item
+ * used to free up unneeded fields without freeing the program being run 
+ */
+int errcount = 0;	/* error counter, used by yyerror() */
+
+/* The global null string */
+NODE *Nnull_string;
+
+/* The name the program was invoked under, for error messages */
+const char *myname;
+
+/* A block of AWK code to be run before running the program */
+NODE *begin_block = 0;
+
+/* A block of AWK code to be run after the last input file */
+NODE *end_block = 0;
+
+int exiting = 0;		/* Was an "exit" statement executed? */
+int exit_val = 0;		/* optional exit value */
+
+#if defined(YYDEBUG) || defined(DEBUG)
+extern int yydebug;
+#endif
+
+struct src *srcfiles = NULL;		/* source file name(s) */
+int numfiles = -1;		/* how many source files */
+
+int do_unix = 0;		/* turn off gnu extensions */
+int do_posix = 0;		/* turn off gnu and unix extensions */
+int do_lint = 0;		/* provide warnings about questionable stuff */
+int do_nostalgia = 0;		/* provide a blast from the past */
+
+int in_begin_rule = 0;		/* we're in a BEGIN rule */
+int in_end_rule = 0;		/* we're in a END rule */
+
+int output_is_tty = 0;		/* control flushing of output */
+
+extern char *version_string;	/* current version, for printing */
+
+NODE *expression_value;
+
+static struct option optab[] = {
+	{ "compat",		no_argument,		& do_unix,	1 },
+	{ "lint",		no_argument,		& do_lint,	1 },
+	{ "posix",		no_argument,		& do_posix,	1 },
+	{ "nostalgia",		no_argument,		& do_nostalgia,	1 },
+	{ "copyleft",		no_argument,		NULL,		'C' },
+	{ "copyright",		no_argument,		NULL,		'C' },
+	{ "field-separator",	required_argument,	NULL,		'F' },
+	{ "file",		required_argument,	NULL,		'f' },
+	{ "assign",		required_argument,	NULL,		'v' },
+	{ "version",		no_argument,		NULL,		'V' },
+	{ "usage",		no_argument,		NULL,		'u' },
+	{ "help",		no_argument,		NULL,		'u' },
+	{ "source",		required_argument,	NULL,		's' },
+#ifdef DEBUG
+	{ "parsedebug",		no_argument,		NULL,		'D' },
+#endif
+	{ 0, 0, 0, 0 }
+};
+
+int
+main(argc, argv)
+int argc;
+char **argv;
+{
+	int c;
+	char *scan;
+	extern int optind;
+	extern int opterr;
+	extern char *optarg;
+	int i;
+
+	(void) signal(SIGFPE,  (SIGTYPE (*) P((int))) catchsig);
+	(void) signal(SIGSEGV, (SIGTYPE (*) P((int))) catchsig);
+#ifdef SIGBUS
+	(void) signal(SIGBUS,  (SIGTYPE (*) P((int))) catchsig);
+#endif
+
+	myname = gawk_name(argv[0]);
+        argv[0] = (char *)myname;
+#ifdef VMS
+	vms_arg_fixup(&argc, &argv); /* emulate redirection, expand wildcards */
+#endif
+
+	/* remove sccs gunk */
+	if (strncmp(version_string, "@(#)", 4) == 0)
+		version_string += 4;
+
+	if (argc < 2)
+		usage(1);
+
+	/* initialize the null string */
+	Nnull_string = make_string("", 0);
+	Nnull_string->numbr = 0.0;
+	Nnull_string->type = Node_val;
+	Nnull_string->flags = (PERM|STR|STRING|NUM|NUMBER);
+
+	/* Set up the special variables */
+
+	/*
+	 * Note that this must be done BEFORE arg parsing else -F
+	 * breaks horribly 
+	 */
+	init_vars();
+
+	/* worst case */
+	emalloc(srcfiles, struct src *, argc * sizeof(struct src), "main");
+	memset(srcfiles, '\0', argc * sizeof(struct src));
+
+	/* Tell the regex routines how they should work. . . */
+	resetup();
+
+	/* we do error messages ourselves on invalid options */
+	opterr = 0;
+
+	/* the + on the front tells GNU getopt not to rearrange argv */
+	while ((c = getopt_long(argc, argv, "+F:f:v:W:", optab, NULL)) != EOF) {
+		if (do_posix)
+			opterr = 1;
+		switch (c) {
+		case 'F':
+			cmdline_fs(optarg);
+			break;
+
+		case 'f':
+			/*
+			 * a la MKS awk, allow multiple -f options.
+			 * this makes function libraries real easy.
+			 * most of the magic is in the scanner.
+			 */
+			/* The following is to allow for whitespace at the end
+			 * of a #! /bin/gawk line in an executable file
+			 */
+			scan = optarg;
+			while (isspace(*scan))
+				scan++;
+			++numfiles;
+			srcfiles[numfiles].stype = SOURCEFILE;
+			if (*scan == '\0')
+				srcfiles[numfiles].val = argv[optind++];
+			else
+				srcfiles[numfiles].val = optarg;
+			break;
+
+		case 'v':
+			pre_assign(optarg);
+			break;
+
+		case 'W':       /* gawk specific options */
+			gawk_option(optarg);
+			break;
+
+		/* These can only come from long form options */
+		case 'V':
+			version();
+			break;
+
+		case 'C':
+			copyleft();
+			break;
+
+		case 'u':
+			usage(0);
+			break;
+
+		case 's':
+			if (strlen(optarg) == 0)
+				warning("empty argument to --source ignored");
+			else {
+				srcfiles[++numfiles].stype = CMDLINE;
+				srcfiles[numfiles].val = optarg;
+			}
+			break;
+
+#ifdef DEBUG
+		case 'D':
+			yydebug = 2;
+			break;
+#endif
+
+		case '?':
+		default:
+			/*
+			 * New behavior.  If not posix, an unrecognized
+			 * option stops argument processing so that it can
+			 * go into ARGV for the awk program to see. This
+			 * makes use of ``#! /bin/gawk -f'' easier.
+			 */
+			if (! do_posix)
+				goto out;
+			/* else
+				let getopt print error message for us */
+			break;
+		}
+	}
+out:
+
+	if (do_nostalgia)
+		nostalgia();
+
+	/* POSIX compliance also implies no Unix extensions either */
+	if (do_posix)
+		do_unix = 1;
+
+#ifdef DEBUG
+	setbuf(stdout, (char *) NULL);	/* make debugging easier */
+#endif
+	if (isatty(fileno(stdout)))
+		output_is_tty = 1;
+	/* No -f or --source options, use next arg */
+	if (numfiles == -1) {
+		if (optind > argc - 1)	/* no args left */
+			usage(1);
+		srcfiles[++numfiles].stype = CMDLINE;
+		srcfiles[numfiles].val = argv[optind];
+		optind++;
+	}
+	init_args(optind, argc, (char *) myname, argv);
+	(void) tokexpand();
+
+	/* Read in the program */
+	if (yyparse() || errcount)
+		exit(1);
+
+	/* Set up the field variables */
+	init_fields();
+
+	if (begin_block) {
+		in_begin_rule = 1;
+		(void) interpret(begin_block);
+	}
+	in_begin_rule = 0;
+	if (!exiting && (expression_value || end_block))
+		do_input();
+	if (end_block) {
+		in_end_rule = 1;
+		(void) interpret(end_block);
+	}
+	in_end_rule = 0;
+	if (close_io() != 0 && exit_val == 0)
+		exit_val = 1;
+	exit(exit_val);		/* more portable */
+	return exit_val;	/* to suppress warnings */
+}
+
+/* usage --- print usage information and exit */
+
+static void
+usage(exitval)
+int exitval;
+{
+	char *opt1 = " -f progfile [--]";
+	char *opt2 = " [--] 'program'";
+	char *regops = " [POSIX or GNU style options]";
+
+	version();
+	fprintf(stderr, "usage: %s%s%s file ...\n       %s%s%s file ...\n",
+		myname, regops, opt1, myname, regops, opt2);
+
+	/* GNU long options info. Gack. */
+	fputs("\nPOSIX options:\t\tGNU long options:\n", stderr);
+	fputs("\t-f progfile\t\t--file=progfile\n", stderr);
+	fputs("\t-F fs\t\t\t--field-separator=fs\n", stderr);
+	fputs("\t-v var=val\t\t--assign=var=val\n", stderr);
+	fputs("\t-W compat\t\t--compat\n", stderr);
+	fputs("\t-W copyleft\t\t--copyleft\n", stderr);
+	fputs("\t-W copyright\t\t--copyright\n", stderr);
+	fputs("\t-W help\t\t\t--help\n", stderr);
+	fputs("\t-W lint\t\t\t--lint\n", stderr);
+#if 0
+	fputs("\t-W nostalgia\t\t--nostalgia\n", stderr);
+#endif
+#ifdef DEBUG
+	fputs("\t-W parsedebug\t\t--parsedebug\n", stderr);
+#endif
+	fputs("\t-W posix\t\t--posix\n", stderr);
+	fputs("\t-W source=program-text\t--source=program-text\n", stderr);
+	fputs("\t-W usage\t\t--usage\n", stderr);
+	fputs("\t-W version\t\t--version\n", stderr);
+	exit(exitval);
+}
+
+static void
+copyleft ()
+{
+	static char blurb_part1[] =
+"Copyright (C) 1989, 1991, 1992, Free Software Foundation.\n\
+\n\
+This program is free software; you can redistribute it and/or modify\n\
+it under the terms of the GNU General Public License as published by\n\
+the Free Software Foundation; either version 2 of the License, or\n\
+(at your option) any later version.\n\
+\n";
+	static char blurb_part2[] =
+"This program is distributed in the hope that it will be useful,\n\
+but WITHOUT ANY WARRANTY; without even the implied warranty of\n\
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n\
+GNU General Public License for more details.\n\
+\n";
+	static char blurb_part3[] =
+"You should have received a copy of the GNU General Public License\n\
+along with this program; if not, write to the Free Software\n\
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.\n";
+
+	version();
+	fputs(blurb_part1, stderr);
+	fputs(blurb_part2, stderr);
+	fputs(blurb_part3, stderr);
+	fflush(stderr);
+}
+
+static void
+cmdline_fs(str)
+char *str;
+{
+	register NODE **tmp;
+	int len = strlen(str);
+
+	tmp = get_lhs(FS_node, (Func_ptr *) 0);
+	unref(*tmp);
+	/*
+	 * Only if in full compatibility mode check for the stupid special
+	 * case so -F\t works as documented in awk even though the shell
+	 * hands us -Ft.  Bleah!
+	 *
+	 * Thankfully, Posix didn't propogate this "feature".
+	 */
+	if (str[0] == 't' && str[1] == '\0') {
+		if (do_lint)
+			warning("-Ft does not set FS to tab in POSIX awk");
+		if (do_unix && ! do_posix)
+			str[0] = '\t';
+	}
+	*tmp = make_str_node(str, len, SCAN);	/* do process escapes */
+	set_FS();
+}
+
+static void
+init_args(argc0, argc, argv0, argv)
+int argc0, argc;
+char *argv0;
+char **argv;
+{
+	int i, j;
+	NODE **aptr;
+
+	ARGV_node = install("ARGV", node(Nnull_string, Node_var, (NODE *)NULL));
+	aptr = assoc_lookup(ARGV_node, tmp_number(0.0));
+	*aptr = make_string(argv0, strlen(argv0));
+	(*aptr)->flags |= MAYBE_NUM;
+	for (i = argc0, j = 1; i < argc; i++) {
+		aptr = assoc_lookup(ARGV_node, tmp_number((AWKNUM) j));
+		*aptr = make_string(argv[i], strlen(argv[i]));
+		(*aptr)->flags |= MAYBE_NUM;
+		j++;
+	}
+	ARGC_node = install("ARGC",
+			node(make_number((AWKNUM) j), Node_var, (NODE *) NULL));
+}
+
+/*
+ * Set all the special variables to their initial values.
+ */
+struct varinit {
+	NODE **spec;
+	char *name;
+	NODETYPE type;
+	char *strval;
+	AWKNUM numval;
+	Func_ptr assign;
+};
+static struct varinit varinit[] = {
+{&NF_node,	"NF",		Node_NF,		0,	-1, set_NF },
+{&FIELDWIDTHS_node, "FIELDWIDTHS", Node_FIELDWIDTHS,	"",	0,  0 },
+{&NR_node,	"NR",		Node_NR,		0,	0,  set_NR },
+{&FNR_node,	"FNR",		Node_FNR,		0,	0,  set_FNR },
+{&FS_node,	"FS",		Node_FS,		" ",	0,  0 },
+{&RS_node,	"RS",		Node_RS,		"\n",	0,  set_RS },
+{&IGNORECASE_node, "IGNORECASE", Node_IGNORECASE,	0,	0,  set_IGNORECASE },
+{&FILENAME_node, "FILENAME",	Node_var,		"-",	0,  0 },
+{&OFS_node,	"OFS",		Node_OFS,		" ",	0,  set_OFS },
+{&ORS_node,	"ORS",		Node_ORS,		"\n",	0,  set_ORS },
+{&OFMT_node,	"OFMT",		Node_OFMT,		"%.6g",	0,  set_OFMT },
+{&CONVFMT_node,	"CONVFMT",	Node_CONVFMT,		"%.6g",	0,  set_CONVFMT },
+{&RLENGTH_node, "RLENGTH",	Node_var,		0,	0,  0 },
+{&RSTART_node,	"RSTART",	Node_var,		0,	0,  0 },
+{&SUBSEP_node,	"SUBSEP",	Node_var,		"\034",	0,  0 },
+{&ARGIND_node,	"ARGIND",	Node_var,		0,	0,  0 },
+{&ERRNO_node,	"ERRNO",	Node_var,		0,	0,  0 },
+{0,		0,		Node_illegal,		0,	0,  0 },
+};
+
+static void
+init_vars()
+{
+	register struct varinit *vp;
+
+	for (vp = varinit; vp->name; vp++) {
+		*(vp->spec) = install(vp->name,
+		  node(vp->strval == 0 ? make_number(vp->numval)
+				: make_string(vp->strval, strlen(vp->strval)),
+		       vp->type, (NODE *) NULL));
+		if (vp->assign)
+			(*(vp->assign))();
+	}
+}
+
+void
+load_environ()
+{
+#if !defined(MSDOS) && !(defined(VMS) && defined(__DECC))
+	extern char **environ;
+#endif
+	register char *var, *val;
+	NODE **aptr;
+	register int i;
+
+	ENVIRON_node = install("ENVIRON", 
+			node(Nnull_string, Node_var, (NODE *) NULL));
+	for (i = 0; environ[i]; i++) {
+		static char nullstr[] = "";
+
+		var = environ[i];
+		val = strchr(var, '=');
+		if (val)
+			*val++ = '\0';
+		else
+			val = nullstr;
+		aptr = assoc_lookup(ENVIRON_node, tmp_string(var, strlen (var)));
+		*aptr = make_string(val, strlen (val));
+		(*aptr)->flags |= MAYBE_NUM;
+
+		/* restore '=' so that system() gets a valid environment */
+		if (val != nullstr)
+			*--val = '=';
+	}
+}
+
+/* Process a command-line assignment */
+char *
+arg_assign(arg)
+char *arg;
+{
+	char *cp;
+	Func_ptr after_assign = NULL;
+	NODE *var;
+	NODE *it;
+	NODE **lhs;
+
+	cp = strchr(arg, '=');
+	if (cp != NULL) {
+		*cp++ = '\0';
+		/*
+		 * Recent versions of nawk expand escapes inside assignments.
+		 * This makes sense, so we do it too.
+		 */
+		it = make_str_node(cp, strlen(cp), SCAN);
+		it->flags |= MAYBE_NUM;
+		var = variable(arg, 0);
+		lhs = get_lhs(var, &after_assign);
+		unref(*lhs);
+		*lhs = it;
+		if (after_assign)
+			(*after_assign)();
+		*--cp = '=';	/* restore original text of ARGV */
+	}
+	return cp;
+}
+
+static void
+pre_assign(v)
+char *v;
+{
+	if (!arg_assign(v)) {
+		fprintf (stderr,
+			"%s: '%s' argument to -v not in 'var=value' form\n",
+				myname, v);
+		usage(1);
+	}
+}
+
+SIGTYPE
+catchsig(sig, code)
+int sig, code;
+{
+#ifdef lint
+	code = 0; sig = code; code = sig;
+#endif
+	if (sig == SIGFPE) {
+		fatal("floating point exception");
+	} else if (sig == SIGSEGV
+#ifdef SIGBUS
+	        || sig == SIGBUS
+#endif
+	) {
+		msg("fatal error: internal error");
+		/* fatal won't abort() if not compiled for debugging */
+		abort();
+	} else
+		cant_happen();
+	/* NOTREACHED */
+}
+
+/* gawk_option --- do gawk specific things */
+
+static void
+gawk_option(optstr)
+char *optstr;
+{
+	char *cp;
+
+	for (cp = optstr; *cp; cp++) {
+		switch (*cp) {
+		case ' ':
+		case '\t':
+		case ',':
+			break;
+		case 'v':
+		case 'V':
+			/* print version */
+			if (strncasecmp(cp, "version", 7) != 0)
+				goto unknown;
+			else
+				cp += 6;
+			version();
+			break;
+		case 'c':
+		case 'C':
+			if (strncasecmp(cp, "copyright", 9) == 0) {
+				cp += 8;
+				copyleft();
+			} else if (strncasecmp(cp, "copyleft", 8) == 0) {
+				cp += 7;
+				copyleft();
+			} else if (strncasecmp(cp, "compat", 6) == 0) {
+				cp += 5;
+				do_unix = 1;
+			} else
+				goto unknown;
+			break;
+		case 'n':
+		case 'N':
+			/*
+			 * Undocumented feature,
+			 * inspired by nostalgia, and a T-shirt
+			 */
+			if (strncasecmp(cp, "nostalgia", 9) != 0)
+				goto unknown;
+			nostalgia();
+			break;
+		case 'p':
+		case 'P':
+#ifdef DEBUG
+			if (strncasecmp(cp, "parsedebug", 10) == 0) {
+				cp += 9;
+				yydebug = 2;
+				break;
+			}
+#endif
+			if (strncasecmp(cp, "posix", 5) != 0)
+				goto unknown;
+			cp += 4;
+			do_posix = do_unix = 1;
+			break;
+		case 'l':
+		case 'L':
+			if (strncasecmp(cp, "lint", 4) != 0)
+				goto unknown;
+			cp += 3;
+			do_lint = 1;
+			break;
+		case 'H':
+		case 'h':
+			if (strncasecmp(cp, "help", 4) != 0)
+				goto unknown;
+			cp += 3;
+			usage(0);
+			break;
+		case 'U':
+		case 'u':
+			if (strncasecmp(cp, "usage", 5) != 0)
+				goto unknown;
+			cp += 4;
+			usage(0);
+			break;
+		case 's':
+		case 'S':
+			if (strncasecmp(cp, "source=", 7) != 0)
+				goto unknown;
+			cp += 7;
+			if (strlen(cp) == 0)
+				warning("empty argument to -Wsource ignored");
+			else {
+				srcfiles[++numfiles].stype = CMDLINE;
+				srcfiles[numfiles].val = cp;
+				return;
+			}
+			break;
+		default:
+		unknown:
+			fprintf(stderr, "'%c' -- unknown option, ignored\n",
+				*cp);
+			break;
+		}
+	}
+}
+
+/* nostalgia --- print the famous error message and die */
+
+static void
+nostalgia()
+{
+	fprintf(stderr, "awk: bailing out near line 1\n");
+	abort();
+}
+
+/* version --- print version message */
+
+static void
+version()
+{
+	fprintf(stderr, "%s, patchlevel %d\n", version_string, PATCHLEVEL);
+}
+
+/* static */
+char *
+gawk_name(filespec)
+char *filespec;
+{
+        char *p;
+    
+#ifdef VMS	/* "device:[root.][directory.subdir]GAWK.EXE;n" -> "GAWK" */
+        char *q;
+
+        p = strrchr(filespec, ']');  /* directory punctuation */
+        q = strrchr(filespec, '>');  /* alternate <international> punct */
+
+        if (p == NULL || q > p) p = q;
+	p = strdup(p == NULL ? filespec : (p + 1));
+	if ((q = strrchr(p, '.')) != NULL)  *q = '\0';  /* strip .typ;vers */
+
+	return p;
+#endif /*VMS*/
+
+#if defined(MSDOS) || defined(atarist)
+        char *q;
+
+        p = filespec;
+	
+        if (q = strrchr(p, '\\'))
+            p = q + 1;
+        if (q = strchr(p, '.'))
+    	    *q = '\0';
+        strlwr(p);
+
+        return (p == NULL ? filespec : p);
+#endif /* MSDOS || atarist */
+
+	/* "path/name" -> "name" */
+	p = strrchr(filespec, '/');
+	return (p == NULL ? filespec : p + 1);
+}
diff --git a/gnu/usr.bin/awk/msg.c b/gnu/usr.bin/awk/msg.c
new file mode 100644
index 000000000000..b60fe9d1e5e9
--- /dev/null
+++ b/gnu/usr.bin/awk/msg.c
@@ -0,0 +1,106 @@
+/*
+ * msg.c - routines for error messages
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "awk.h"
+
+int sourceline = 0;
+char *source = NULL;
+
+/* VARARGS2 */
+void
+err(s, emsg, argp)
+char *s;
+char *emsg;
+va_list argp;
+{
+	char *file;
+
+	(void) fflush(stdout);
+	(void) fprintf(stderr, "%s: ", myname);
+	if (sourceline) {
+		if (source)
+			(void) fprintf(stderr, "%s:", source);
+		else
+			(void) fprintf(stderr, "cmd. line:");
+
+		(void) fprintf(stderr, "%d: ", sourceline);
+	}
+	if (FNR) {
+		file = FILENAME_node->var_value->stptr;
+		if (file)
+			(void) fprintf(stderr, "(FILENAME=%s ", file);
+		(void) fprintf(stderr, "FNR=%d) ", FNR);
+	}
+	(void) fprintf(stderr, s);
+	vfprintf(stderr, emsg, argp);
+	(void) fprintf(stderr, "\n");
+	(void) fflush(stderr);
+}
+
+/*VARARGS0*/
+void
+msg(va_alist)
+va_dcl
+{
+	va_list args;
+	char *mesg;
+
+	va_start(args);
+	mesg = va_arg(args, char *);
+	err("", mesg, args);
+	va_end(args);
+}
+
+/*VARARGS0*/
+void
+warning(va_alist)
+va_dcl
+{
+	va_list args;
+	char *mesg;
+
+	va_start(args);
+	mesg = va_arg(args, char *);
+	err("warning: ", mesg, args);
+	va_end(args);
+}
+
+/*VARARGS0*/
+void
+fatal(va_alist)
+va_dcl
+{
+	va_list args;
+	char *mesg;
+
+	va_start(args);
+	mesg = va_arg(args, char *);
+	err("fatal: ", mesg, args);
+	va_end(args);
+#ifdef DEBUG
+	abort();
+#endif
+	exit(2);
+}
diff --git a/gnu/usr.bin/awk/node.c b/gnu/usr.bin/awk/node.c
new file mode 100644
index 000000000000..65ecb0ed1723
--- /dev/null
+++ b/gnu/usr.bin/awk/node.c
@@ -0,0 +1,429 @@
+/*
+ * node.c -- routines for node management
+ */
+
+/* 
+ * Copyright (C) 1986, 1988, 1989, 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "awk.h"
+
+extern double strtod();
+
+AWKNUM
+r_force_number(n)
+register NODE *n;
+{
+	register char *cp;
+	register char *cpend;
+	char save;
+	char *ptr;
+	unsigned int newflags = 0;
+
+#ifdef DEBUG
+	if (n == NULL)
+		cant_happen();
+	if (n->type != Node_val)
+		cant_happen();
+	if(n->flags == 0)
+		cant_happen();
+	if (n->flags & NUM)
+		return n->numbr;
+#endif
+
+	/* all the conditionals are an attempt to avoid the expensive strtod */
+
+	n->numbr = 0.0;
+	n->flags |= NUM;
+
+	if (n->stlen == 0)
+		return 0.0;
+
+	cp = n->stptr;
+	if (isalpha(*cp))
+		return 0.0;
+
+	cpend = cp + n->stlen;
+	while (cp < cpend && isspace(*cp))
+		cp++;
+	if (cp == cpend || isalpha(*cp))
+		return 0.0;
+
+	if (n->flags & MAYBE_NUM) {
+		newflags = NUMBER;
+		n->flags &= ~MAYBE_NUM;
+	}
+	if (cpend - cp == 1) {
+		if (isdigit(*cp)) {
+			n->numbr = (AWKNUM)(*cp - '0');
+			n->flags |= newflags;
+		}
+		return n->numbr;
+	}
+
+	errno = 0;
+	save = *cpend;
+	*cpend = '\0';
+	n->numbr = (AWKNUM) strtod((const char *)cp, &ptr);
+
+	/* POSIX says trailing space is OK for NUMBER */
+	while (isspace(*ptr))
+		ptr++;
+	*cpend = save;
+	/* the >= should be ==, but for SunOS 3.5 strtod() */
+	if (errno == 0 && ptr >= cpend)
+		n->flags |= newflags;
+	else
+		errno = 0;
+
+	return n->numbr;
+}
+
+/*
+ * the following lookup table is used as an optimization in force_string
+ * (more complicated) variations on this theme didn't seem to pay off, but 
+ * systematic testing might be in order at some point
+ */
+static char *values[] = {
+	"0",
+	"1",
+	"2",
+	"3",
+	"4",
+	"5",
+	"6",
+	"7",
+	"8",
+	"9",
+};
+#define	NVAL	(sizeof(values)/sizeof(values[0]))
+
+NODE *
+r_force_string(s)
+register NODE *s;
+{
+	char buf[128];
+	register char *sp = buf;
+	register long num = 0;
+
+#ifdef DEBUG
+	if (s == NULL) cant_happen();
+	if (s->type != Node_val) cant_happen();
+	if (s->flags & STR) return s;
+	if (!(s->flags & NUM)) cant_happen();
+	if (s->stref != 0) ; /*cant_happen();*/
+#endif
+
+        /* avoids floating point exception in DOS*/
+        if ( s->numbr <= LONG_MAX && s->numbr >= -LONG_MAX)
+		num = (long)s->numbr;
+	if ((AWKNUM) num == s->numbr) {	/* integral value */
+		if (num < NVAL && num >= 0) {
+			sp = values[num];
+			s->stlen = 1;
+		} else {
+			(void) sprintf(sp, "%ld", num);
+			s->stlen = strlen(sp);
+		}
+		s->stfmt = -1;
+	} else {
+		(void) sprintf(sp, CONVFMT, s->numbr);
+		s->stlen = strlen(sp);
+		s->stfmt = (char)CONVFMTidx;
+	}
+	s->stref = 1;
+	emalloc(s->stptr, char *, s->stlen + 2, "force_string");
+	memcpy(s->stptr, sp, s->stlen+1);
+	s->flags |= STR;
+	return s;
+}
+
+/*
+ * Duplicate a node.  (For strings, "duplicate" means crank up the
+ * reference count.)
+ */
+NODE *
+dupnode(n)
+NODE *n;
+{
+	register NODE *r;
+
+	if (n->flags & TEMP) {
+		n->flags &= ~TEMP;
+		n->flags |= MALLOC;
+		return n;
+	}
+	if ((n->flags & (MALLOC|STR)) == (MALLOC|STR)) {
+		if (n->stref < 255)
+			n->stref++;
+		return n;
+	}
+	getnode(r);
+	*r = *n;
+	r->flags &= ~(PERM|TEMP);
+	r->flags |= MALLOC;
+	if (n->type == Node_val && (n->flags & STR)) {
+		r->stref = 1;
+		emalloc(r->stptr, char *, r->stlen + 2, "dupnode");
+		memcpy(r->stptr, n->stptr, r->stlen+1);
+	}
+	return r;
+}
+
+/* this allocates a node with defined numbr */
+NODE *
+mk_number(x, flags)
+AWKNUM x;
+unsigned int flags;
+{
+	register NODE *r;
+
+	getnode(r);
+	r->type = Node_val;
+	r->numbr = x;
+	r->flags = flags;
+#ifdef DEBUG
+	r->stref = 1;
+	r->stptr = 0;
+	r->stlen = 0;
+#endif
+	return r;
+}
+
+/*
+ * Make a string node.
+ */
+NODE *
+make_str_node(s, len, flags)
+char *s;
+size_t len;
+int flags;
+{
+	register NODE *r;
+
+	getnode(r);
+	r->type = Node_val;
+	r->flags = (STRING|STR|MALLOC);
+	if (flags & ALREADY_MALLOCED)
+		r->stptr = s;
+	else {
+		emalloc(r->stptr, char *, len + 2, s);
+		memcpy(r->stptr, s, len);
+	}
+	r->stptr[len] = '\0';
+	       
+	if (flags & SCAN) {	/* scan for escape sequences */
+		char *pf;
+		register char *ptm;
+		register int c;
+		register char *end;
+
+		end = &(r->stptr[len]);
+		for (pf = ptm = r->stptr; pf < end;) {
+			c = *pf++;
+			if (c == '\\') {
+				c = parse_escape(&pf);
+				if (c < 0) {
+					if (do_lint)
+						warning("backslash at end of string");
+					c = '\\';
+				}
+				*ptm++ = c;
+			} else
+				*ptm++ = c;
+		}
+		len = ptm - r->stptr;
+		erealloc(r->stptr, char *, len + 1, "make_str_node");
+		r->stptr[len] = '\0';
+		r->flags |= PERM;
+	}
+	r->stlen = len;
+	r->stref = 1;
+	r->stfmt = -1;
+
+	return r;
+}
+
+NODE *
+tmp_string(s, len)
+char *s;
+size_t len;
+{
+	register NODE *r;
+
+	r = make_string(s, len);
+	r->flags |= TEMP;
+	return r;
+}
+
+
+#define NODECHUNK	100
+
+NODE *nextfree = NULL;
+
+NODE *
+more_nodes()
+{
+	register NODE *np;
+
+	/* get more nodes and initialize list */
+	emalloc(nextfree, NODE *, NODECHUNK * sizeof(NODE), "newnode");
+	for (np = nextfree; np < &nextfree[NODECHUNK - 1]; np++)
+		np->nextp = np + 1;
+	np->nextp = NULL;
+	np = nextfree;
+	nextfree = nextfree->nextp;
+	return np;
+}
+
+#ifdef DEBUG
+void
+freenode(it)
+NODE *it;
+{
+#ifdef MPROF
+	it->stref = 0;
+	free((char *) it);
+#else	/* not MPROF */
+	/* add it to head of freelist */
+	it->nextp = nextfree;
+	nextfree = it;
+#endif	/* not MPROF */
+}
+#endif	/* DEBUG */
+
+void
+unref(tmp)
+register NODE *tmp;
+{
+	if (tmp == NULL)
+		return;
+	if (tmp->flags & PERM)
+		return;
+	if (tmp->flags & (MALLOC|TEMP)) {
+		tmp->flags &= ~TEMP;
+		if (tmp->flags & STR) {
+			if (tmp->stref > 1) {
+				if (tmp->stref != 255)
+					tmp->stref--;
+				return;
+			}
+			free(tmp->stptr);
+		}
+		freenode(tmp);
+	}
+}
+
+/*
+ * Parse a C escape sequence.  STRING_PTR points to a variable containing a
+ * pointer to the string to parse.  That pointer is updated past the
+ * characters we use.  The value of the escape sequence is returned. 
+ *
+ * A negative value means the sequence \ newline was seen, which is supposed to
+ * be equivalent to nothing at all. 
+ *
+ * If \ is followed by a null character, we return a negative value and leave
+ * the string pointer pointing at the null character. 
+ *
+ * If \ is followed by 000, we return 0 and leave the string pointer after the
+ * zeros.  A value of 0 does not mean end of string.  
+ *
+ * Posix doesn't allow \x.
+ */
+
+int
+parse_escape(string_ptr)
+char **string_ptr;
+{
+	register int c = *(*string_ptr)++;
+	register int i;
+	register int count;
+
+	switch (c) {
+	case 'a':
+		return BELL;
+	case 'b':
+		return '\b';
+	case 'f':
+		return '\f';
+	case 'n':
+		return '\n';
+	case 'r':
+		return '\r';
+	case 't':
+		return '\t';
+	case 'v':
+		return '\v';
+	case '\n':
+		return -2;
+	case 0:
+		(*string_ptr)--;
+		return -1;
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+		i = c - '0';
+		count = 0;
+		while (++count < 3) {
+			if ((c = *(*string_ptr)++) >= '0' && c <= '7') {
+				i *= 8;
+				i += c - '0';
+			} else {
+				(*string_ptr)--;
+				break;
+			}
+		}
+		return i;
+	case 'x':
+		if (do_lint) {
+			static int didwarn;
+
+			if (! didwarn) {
+				didwarn = 1;
+				warning("Posix does not allow \"\\x\" escapes");
+			}
+		}
+		if (do_posix)
+			return ('x');
+		i = 0;
+		while (1) {
+			if (isxdigit((c = *(*string_ptr)++))) {
+				i *= 16;
+				if (isdigit(c))
+					i += c - '0';
+				else if (isupper(c))
+					i += c - 'A' + 10;
+				else
+					i += c - 'a' + 10;
+			} else {
+				(*string_ptr)--;
+				break;
+			}
+		}
+		return i;
+	default:
+		return c;
+	}
+}
diff --git a/gnu/usr.bin/awk/patchlevel.h b/gnu/usr.bin/awk/patchlevel.h
new file mode 100644
index 000000000000..c6161a1f274c
--- /dev/null
+++ b/gnu/usr.bin/awk/patchlevel.h
@@ -0,0 +1 @@
+#define PATCHLEVEL	2
diff --git a/gnu/usr.bin/awk/protos.h b/gnu/usr.bin/awk/protos.h
new file mode 100644
index 000000000000..25af32165b02
--- /dev/null
+++ b/gnu/usr.bin/awk/protos.h
@@ -0,0 +1,115 @@
+/*
+ * protos.h -- function prototypes for when the headers don't have them.
+ */
+
+/* 
+ * Copyright (C) 1991, 1992, the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifdef __STDC__
+#define aptr_t void *	/* arbitrary pointer type */
+#else
+#define aptr_t char *
+#endif
+extern aptr_t malloc P((MALLOC_ARG_T));
+extern aptr_t realloc P((aptr_t, MALLOC_ARG_T));
+extern aptr_t calloc P((MALLOC_ARG_T, MALLOC_ARG_T));
+
+extern void free P((aptr_t));
+extern char *getenv P((char *));
+
+extern char *strcpy P((char *, const char *));
+extern char *strcat P((char *, const char *));
+extern char *strncpy P((char *, const char *, int));
+extern int strcmp P((const char *, const char *));
+extern int strncmp P((const char *, const char *, int));
+#ifndef VMS
+extern char *strerror P((int));
+#else
+extern char *strerror P((int,...));
+#endif
+extern char *strchr P((const char *, int));
+extern char *strrchr P((const char *, int));
+extern char *strstr P((const char *s1, const char *s2));
+extern int strlen P((const char *));
+extern long strtol P((const char *, char **, int));
+#if !defined(_MSC_VER) && !defined(__GNU_LIBRARY__)
+extern int strftime P((char *, int, const char *, const struct tm *));
+#endif
+extern time_t time P((time_t *));
+extern aptr_t memset P((aptr_t, int, size_t));
+extern aptr_t memcpy P((aptr_t, const aptr_t, size_t));
+extern aptr_t memmove P((aptr_t, const aptr_t, size_t));
+extern aptr_t memchr P((const aptr_t, int, size_t));
+extern int memcmp P((const aptr_t, const aptr_t, size_t));
+
+/* extern int fprintf P((FILE *, char *, ...)); */
+extern int fprintf P(());
+#if !defined(MSDOS) && !defined(__GNU_LIBRARY__)
+extern int fwrite P((const char *, int, int, FILE *));
+extern int fputs P((const char *, FILE *));
+extern int unlink P((const char *));
+#endif
+extern int fflush P((FILE *));
+extern int fclose P((FILE *));
+extern FILE *popen P((const char *, const char *));
+extern int pclose P((FILE *));
+extern void abort P(());
+extern int isatty P((int));
+extern void exit P((int));
+extern int system P((const char *));
+extern int sscanf P((/* char *, char *, ... */));
+#ifndef toupper
+extern int toupper P((int));
+#endif
+#ifndef tolower
+extern int tolower P((int));
+#endif
+
+extern double pow P((double x, double y));
+extern double atof P((char *));
+extern double strtod P((const char *, char **));
+extern int fstat P((int, struct stat *));
+extern int stat P((const char *, struct stat *));
+extern off_t lseek P((int, off_t, int));
+extern int fseek P((FILE *, long, int));
+extern int close P((int));
+extern int creat P(());
+extern int open P(());
+extern int pipe P((int *));
+extern int dup P((int));
+extern int dup2 P((int,int));
+extern int fork P(());
+extern int execl P((/* char *, char *, ... */));
+extern int read P((int, char *, int));
+extern int wait P((int *));
+extern void _exit P((int));
+
+#ifndef __STDC__
+extern long time P((long *));
+#endif
+
+#ifdef NON_STD_SPRINTF
+extern char *sprintf();
+#else
+extern int sprintf();
+#endif /* SPRINTF_INT */
+
+#undef aptr_t
diff --git a/gnu/usr.bin/awk/re.c b/gnu/usr.bin/awk/re.c
new file mode 100644
index 000000000000..495b0963cadb
--- /dev/null
+++ b/gnu/usr.bin/awk/re.c
@@ -0,0 +1,208 @@
+/*
+ * re.c - compile regular expressions.
+ */
+
+/* 
+ * Copyright (C) 1991, 1992 the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Progamming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GAWK; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "awk.h"
+
+/* Generate compiled regular expressions */
+
+Regexp *
+make_regexp(s, len, ignorecase, dfa)
+char *s;
+int len;
+int ignorecase;
+int dfa;
+{
+	Regexp *rp;
+	char *err;
+	char *src = s;
+	char *temp;
+	char *end = s + len;
+	register char *dest;
+	register int c;
+
+	/* Handle escaped characters first. */
+
+	/* Build a copy of the string (in dest) with the
+	   escaped characters translated,  and generate the regex
+	   from that.  
+	*/
+	emalloc(dest, char *, len + 2, "make_regexp");
+	temp = dest;
+
+	while (src < end) {
+		if (*src == '\\') {
+			c = *++src;
+			switch (c) {
+			case 'a':
+			case 'b':
+			case 'f':
+			case 'n':
+			case 'r':
+			case 't':
+			case 'v':
+			case 'x':
+			case '0':
+			case '1':
+			case '2':
+			case '3':
+			case '4':
+			case '5':
+			case '6':
+			case '7':
+				c = parse_escape(&src);
+				if (c < 0)
+					cant_happen();
+				*dest++ = (char)c;
+				break;
+			default:
+				*dest++ = '\\';
+				*dest++ = (char)c;
+				src++;
+				break;
+			} /* switch */
+		} else {
+			*dest++ = *src++;	/* not '\\' */
+		}
+	} /* for */
+
+	*dest = '\0' ;	/* Only necessary if we print dest ? */
+	emalloc(rp, Regexp *, sizeof(*rp), "make_regexp");
+	memset((char *) rp, 0, sizeof(*rp));
+	emalloc(rp->pat.buffer, char *, 16, "make_regexp");
+	rp->pat.allocated = 16;
+	emalloc(rp->pat.fastmap, char *, 256, "make_regexp");
+
+	if (ignorecase)
+		rp->pat.translate = casetable;
+	else
+		rp->pat.translate = NULL;
+	len = dest - temp;
+	if ((err = re_compile_pattern(temp, (size_t) len, &(rp->pat))) != NULL)
+		fatal("%s: /%s/", err, temp);
+	if (dfa && !ignorecase) {
+		regcompile(temp, len, &(rp->dfareg), 1);
+		rp->dfa = 1;
+	} else
+		rp->dfa = 0;
+	free(temp);
+	return rp;
+}
+
+int
+research(rp, str, start, len, need_start)
+Regexp *rp;
+register char *str;
+int start;
+register int len;
+int need_start;
+{
+	char *ret = str;
+
+	if (rp->dfa) {
+		char save1;
+		char save2;
+		int count = 0;
+		int try_backref;
+
+		save1 = str[start+len];
+		str[start+len] = '\n';
+		save2 = str[start+len+1];
+		ret = regexecute(&(rp->dfareg), str+start, str+start+len+1, 1,
+					&count, &try_backref);
+		str[start+len] = save1;
+		str[start+len+1] = save2;
+	}
+	if (ret) {
+		if (need_start || rp->dfa == 0)
+			return re_search(&(rp->pat), str, start+len, start,
+					len, &(rp->regs));
+		else
+			return 1;
+	 } else
+		return -1;
+}
+
+void
+refree(rp)
+Regexp *rp;
+{
+	free(rp->pat.buffer);
+	free(rp->pat.fastmap);
+	if (rp->dfa)
+		reg_free(&(rp->dfareg));
+	free(rp);
+}
+
+void
+reg_error(s)
+const char *s;
+{
+	fatal(s);
+}
+
+Regexp *
+re_update(t)
+NODE *t;
+{
+	NODE *t1;
+
+#	define	CASE	1
+	if ((t->re_flags & CASE) == IGNORECASE) {
+		if (t->re_flags & CONST)
+			return t->re_reg;
+		t1 = force_string(tree_eval(t->re_exp));
+		if (t->re_text) {
+			if (cmp_nodes(t->re_text, t1) == 0) {
+				free_temp(t1);
+				return t->re_reg;
+			}
+			unref(t->re_text);
+		}
+		t->re_text = dupnode(t1);
+		free_temp(t1);
+	}
+	if (t->re_reg)
+		refree(t->re_reg);
+	if (t->re_cnt)
+		t->re_cnt++;
+	if (t->re_cnt > 10)
+		t->re_cnt = 0;
+	if (!t->re_text) {
+		t1 = force_string(tree_eval(t->re_exp));
+		t->re_text = dupnode(t1);
+		free_temp(t1);
+	}
+	t->re_reg = make_regexp(t->re_text->stptr, t->re_text->stlen, IGNORECASE, t->re_cnt);
+	t->re_flags &= ~CASE;
+	t->re_flags |= IGNORECASE;
+	return t->re_reg;
+}
+
+void
+resetup()
+{
+	(void) re_set_syntax(RE_SYNTAX_AWK);
+	regsyntax(RE_SYNTAX_AWK, 0);
+}
diff --git a/gnu/usr.bin/awk/regex.c b/gnu/usr.bin/awk/regex.c
new file mode 100644
index 000000000000..f4dd4c2cd24d
--- /dev/null
+++ b/gnu/usr.bin/awk/regex.c
@@ -0,0 +1,2854 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 1985, 1989-90 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 1, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+
+/* To test, compile with -Dtest.  This Dtestable feature turns this into
+   a self-contained program which reads a pattern, describes how it
+   compiles, then reads a string and searches for it.
+   
+   On the other hand, if you compile with both -Dtest and -Dcanned you
+   can run some tests we've already thought of.  */
+
+
+#ifdef emacs
+
+/* The `emacs' switch turns on certain special matching commands
+  that make sense only in emacs. */
+
+#include "lisp.h"
+#include "buffer.h"
+#include "syntax.h"
+
+/* We write fatal error messages on standard error.  */
+#include <stdio.h>
+
+/* isalpha(3) etc. are used for the character classes.  */
+#include <ctype.h>
+
+#else	/* not emacs */
+
+#include "awk.h"
+
+#define	NO_ALLOCA	/* try it out for now */
+#ifndef NO_ALLOCA
+/* Make alloca work the best possible way.  */
+#ifdef __GNUC__
+#ifndef atarist
+#ifndef alloca
+#define alloca __builtin_alloca
+#endif
+#endif /* atarist */
+#else
+#if defined(sparc) && !defined(__GNUC__)
+#include <alloca.h>
+#else
+char *alloca ();
+#endif
+#endif /* __GNUC__ */
+
+#define FREE_AND_RETURN_VOID(stackb)	return
+#define FREE_AND_RETURN(stackb,val)	return(val)
+#define DOUBLE_STACK(stackx,stackb,len) \
+        (stackx = (unsigned char **) alloca (2 * len			\
+                                            * sizeof (unsigned char *)),\
+	/* Only copy what is in use.  */				\
+        (unsigned char **) memcpy (stackx, stackb, len * sizeof (char *)))
+#else  /* NO_ALLOCA defined */
+#define FREE_AND_RETURN_VOID(stackb)   free(stackb);return
+#define FREE_AND_RETURN(stackb,val)    free(stackb);return(val)
+#define DOUBLE_STACK(stackx,stackb,len) \
+        (unsigned char **) realloc (stackb, 2 * len * sizeof (unsigned char *))
+#endif /* NO_ALLOCA */
+
+static void store_jump P((char *, int, char *));
+static void insert_jump P((int, char *, char *, char *));
+static void store_jump_n P((char *, int, char *, unsigned));
+static void insert_jump_n P((int, char *, char *, char *, unsigned));
+static void insert_op_2 P((int, char *, char *, int, int ));
+static int memcmp_translate P((unsigned char *, unsigned char *,
+			       int, unsigned char *));
+long re_set_syntax P((long));
+
+/* Define the syntax stuff, so we can do the \<, \>, etc.  */
+
+/* This must be nonzero for the wordchar and notwordchar pattern
+   commands in re_match_2.  */
+#ifndef Sword 
+#define Sword 1
+#endif
+
+#define SYNTAX(c) re_syntax_table[c]
+
+
+#ifdef SYNTAX_TABLE
+
+char *re_syntax_table;
+
+#else /* not SYNTAX_TABLE */
+
+static char re_syntax_table[256];
+static void init_syntax_once P((void));
+
+
+static void
+init_syntax_once ()
+{
+   register int c;
+   static int done = 0;
+
+   if (done)
+     return;
+
+   memset (re_syntax_table, 0, sizeof re_syntax_table);
+
+   for (c = 'a'; c <= 'z'; c++)
+     re_syntax_table[c] = Sword;
+
+   for (c = 'A'; c <= 'Z'; c++)
+     re_syntax_table[c] = Sword;
+
+   for (c = '0'; c <= '9'; c++)
+     re_syntax_table[c] = Sword;
+ 
+   /* Add specific syntax for ISO Latin-1.  */
+   for (c = 0300; c <= 0377; c++)
+     re_syntax_table[c] = Sword;
+   re_syntax_table[0327] = 0;
+   re_syntax_table[0367] = 0;
+
+   done = 1;
+}
+
+#endif /* SYNTAX_TABLE */
+#undef P
+#endif /* emacs */
+
+
+/* Sequents are missing isgraph.  */
+#ifndef isgraph
+#define isgraph(c) (isprint((c)) && !isspace((c)))
+#endif
+
+/* Get the interface, including the syntax bits.  */
+#include "regex.h"
+
+
+/* These are the command codes that appear in compiled regular
+   expressions, one per byte.  Some command codes are followed by
+   argument bytes.  A command code can specify any interpretation
+   whatsoever for its arguments.  Zero-bytes may appear in the compiled
+   regular expression.
+   
+   The value of `exactn' is needed in search.c (search_buffer) in emacs.
+   So regex.h defines a symbol `RE_EXACTN_VALUE' to be 1; the value of
+   `exactn' we use here must also be 1.  */
+
+enum regexpcode
+  {
+    unused=0,
+    exactn=1, /* Followed by one byte giving n, then by n literal bytes.  */
+    begline,  /* Fail unless at beginning of line.  */
+    endline,  /* Fail unless at end of line.  */
+    jump,     /* Followed by two bytes giving relative address to jump to.  */
+    on_failure_jump,	 /* Followed by two bytes giving relative address of 
+			    place to resume at in case of failure.  */
+    finalize_jump,	 /* Throw away latest failure point and then jump to 
+			    address.  */
+    maybe_finalize_jump, /* Like jump but finalize if safe to do so.
+			    This is used to jump back to the beginning
+			    of a repeat.  If the command that follows
+			    this jump is clearly incompatible with the
+			    one at the beginning of the repeat, such that
+			    we can be sure that there is no use backtracking
+			    out of repetitions already completed,
+			    then we finalize.  */
+    dummy_failure_jump,  /* Jump, and push a dummy failure point. This 
+			    failure point will be thrown away if an attempt 
+                            is made to use it for a failure. A + construct 
+                            makes this before the first repeat.  Also
+                            use it as an intermediary kind of jump when
+                            compiling an or construct.  */
+    succeed_n,	 /* Used like on_failure_jump except has to succeed n times;
+		    then gets turned into an on_failure_jump. The relative
+                    address following it is useless until then.  The
+                    address is followed by two bytes containing n.  */
+    jump_n,	 /* Similar to jump, but jump n times only; also the relative
+		    address following is in turn followed by yet two more bytes
+                    containing n.  */
+    set_number_at,	/* Set the following relative location to the
+			   subsequent number.  */
+    anychar,	 /* Matches any (more or less) one character.  */
+    charset,     /* Matches any one char belonging to specified set.
+		    First following byte is number of bitmap bytes.
+		    Then come bytes for a bitmap saying which chars are in.
+		    Bits in each byte are ordered low-bit-first.
+		    A character is in the set if its bit is 1.
+		    A character too large to have a bit in the map
+		    is automatically not in the set.  */
+    charset_not, /* Same parameters as charset, but match any character
+                    that is not one of those specified.  */
+    start_memory, /* Start remembering the text that is matched, for
+		    storing in a memory register.  Followed by one
+                    byte containing the register number.  Register numbers
+                    must be in the range 0 through RE_NREGS.  */
+    stop_memory, /* Stop remembering the text that is matched
+		    and store it in a memory register.  Followed by
+                    one byte containing the register number. Register
+                    numbers must be in the range 0 through RE_NREGS.  */
+    duplicate,   /* Match a duplicate of something remembered.
+		    Followed by one byte containing the index of the memory 
+                    register.  */
+    before_dot,	 /* Succeeds if before point.  */
+    at_dot,	 /* Succeeds if at point.  */
+    after_dot,	 /* Succeeds if after point.  */
+    begbuf,      /* Succeeds if at beginning of buffer.  */
+    endbuf,      /* Succeeds if at end of buffer.  */
+    wordchar,    /* Matches any word-constituent character.  */
+    notwordchar, /* Matches any char that is not a word-constituent.  */
+    wordbeg,	 /* Succeeds if at word beginning.  */
+    wordend,	 /* Succeeds if at word end.  */
+    wordbound,   /* Succeeds if at a word boundary.  */
+    notwordbound,/* Succeeds if not at a word boundary.  */
+    syntaxspec,  /* Matches any character whose syntax is specified.
+		    followed by a byte which contains a syntax code,
+                    e.g., Sword.  */
+    notsyntaxspec /* Matches any character whose syntax differs from
+                     that specified.  */
+  };
+
+ 
+/* Number of failure points to allocate space for initially,
+   when matching.  If this number is exceeded, more space is allocated,
+   so it is not a hard limit.  */
+
+#ifndef NFAILURES
+#define NFAILURES 80
+#endif
+
+#ifdef CHAR_UNSIGNED
+#define SIGN_EXTEND_CHAR(c) ((c)>(char)127?(c)-256:(c)) /* for IBM RT */
+#endif
+#ifndef SIGN_EXTEND_CHAR
+#define SIGN_EXTEND_CHAR(x) (x)
+#endif
+ 
+
+/* Store NUMBER in two contiguous bytes starting at DESTINATION.  */
+#define STORE_NUMBER(destination, number)				\
+  { (destination)[0] = (number) & 0377;					\
+    (destination)[1] = (number) >> 8; }
+  
+/* Same as STORE_NUMBER, except increment the destination pointer to
+   the byte after where the number is stored.  Watch out that values for
+   DESTINATION such as p + 1 won't work, whereas p will.  */
+#define STORE_NUMBER_AND_INCR(destination, number)			\
+  { STORE_NUMBER(destination, number);					\
+    (destination) += 2; }
+
+
+/* Put into DESTINATION a number stored in two contingous bytes starting
+   at SOURCE.  */
+#define EXTRACT_NUMBER(destination, source)				\
+  { (destination) = *(source) & 0377;					\
+    (destination) += SIGN_EXTEND_CHAR (*(char *)((source) + 1)) << 8; }
+
+/* Same as EXTRACT_NUMBER, except increment the pointer for source to
+   point to second byte of SOURCE.  Note that SOURCE has to be a value
+   such as p, not, e.g., p + 1. */
+#define EXTRACT_NUMBER_AND_INCR(destination, source)			\
+  { EXTRACT_NUMBER (destination, source);				\
+    (source) += 2; }
+
+
+/* Specify the precise syntax of regexps for compilation.  This provides
+   for compatibility for various utilities which historically have
+   different, incompatible syntaxes.
+   
+   The argument SYNTAX is a bit-mask comprised of the various bits
+   defined in regex.h.  */
+
+long
+re_set_syntax (syntax)
+  long syntax;
+{
+  long ret;
+
+  ret = obscure_syntax;
+  obscure_syntax = syntax;
+  return ret;
+}
+
+/* Set by re_set_syntax to the current regexp syntax to recognize.  */
+long obscure_syntax = 0;
+
+
+
+/* Macros for re_compile_pattern, which is found below these definitions.  */
+
+#define CHAR_CLASS_MAX_LENGTH  6
+
+/* Fetch the next character in the uncompiled pattern, translating it if
+   necessary.  */
+#define PATFETCH(c)							\
+  {if (p == pend) goto end_of_pattern;					\
+  c = * (unsigned char *) p++;						\
+  if (translate) c = translate[c]; }
+
+/* Fetch the next character in the uncompiled pattern, with no
+   translation.  */
+#define PATFETCH_RAW(c)							\
+ {if (p == pend) goto end_of_pattern;					\
+  c = * (unsigned char *) p++; }
+
+#define PATUNFETCH p--
+
+
+/* If the buffer isn't allocated when it comes in, use this.  */
+#define INIT_BUF_SIZE  28
+
+/* Make sure we have at least N more bytes of space in buffer.  */
+#define GET_BUFFER_SPACE(n)						\
+  {								        \
+    while (b - bufp->buffer + (n) >= bufp->allocated)			\
+      EXTEND_BUFFER;							\
+  }
+
+/* Make sure we have one more byte of buffer space and then add CH to it.  */
+#define BUFPUSH(ch)							\
+  {									\
+    GET_BUFFER_SPACE (1);						\
+    *b++ = (char) (ch);							\
+  }
+  
+/* Extend the buffer by twice its current size via reallociation and
+   reset the pointers that pointed into the old allocation to point to
+   the correct places in the new allocation.  If extending the buffer
+   results in it being larger than 1 << 16, then flag memory exhausted.  */
+#define EXTEND_BUFFER							\
+  { char *old_buffer = bufp->buffer;					\
+    if (bufp->allocated == (1L<<16)) goto too_big;			\
+    bufp->allocated *= 2;						\
+    if (bufp->allocated > (1L<<16)) bufp->allocated = (1L<<16);		\
+    bufp->buffer = (char *) realloc (bufp->buffer, bufp->allocated);	\
+    if (bufp->buffer == 0)						\
+      goto memory_exhausted;						\
+    b = (b - old_buffer) + bufp->buffer;				\
+    if (fixup_jump)							\
+      fixup_jump = (fixup_jump - old_buffer) + bufp->buffer;		\
+    if (laststart)							\
+      laststart = (laststart - old_buffer) + bufp->buffer;		\
+    begalt = (begalt - old_buffer) + bufp->buffer;			\
+    if (pending_exact)							\
+      pending_exact = (pending_exact - old_buffer) + bufp->buffer;	\
+  }
+
+/* Set the bit for character C in a character set list.  */
+#define SET_LIST_BIT(c)  (b[(c) / BYTEWIDTH] |= 1 << ((c) % BYTEWIDTH))
+
+/* Get the next unsigned number in the uncompiled pattern.  */
+#define GET_UNSIGNED_NUMBER(num) 					\
+  { if (p != pend) 							\
+      { 								\
+        PATFETCH (c); 							\
+	while (isdigit (c)) 						\
+	  { 								\
+	    if (num < 0) 						\
+	       num = 0; 						\
+            num = num * 10 + c - '0'; 					\
+	    if (p == pend) 						\
+	       break; 							\
+	    PATFETCH (c); 						\
+	  } 								\
+        } 								\
+  }
+
+/* Subroutines for re_compile_pattern.  */
+/* static void store_jump (), insert_jump (), store_jump_n (),
+	    insert_jump_n (), insert_op_2 (); */
+
+
+/* re_compile_pattern takes a regular-expression string
+   and converts it into a buffer full of byte commands for matching.
+
+   PATTERN   is the address of the pattern string
+   SIZE      is the length of it.
+   BUFP	    is a  struct re_pattern_buffer *  which points to the info
+	     on where to store the byte commands.
+	     This structure contains a  char *  which points to the
+	     actual space, which should have been obtained with malloc.
+	     re_compile_pattern may use realloc to grow the buffer space.
+
+   The number of bytes of commands can be found out by looking in
+   the `struct re_pattern_buffer' that bufp pointed to, after
+   re_compile_pattern returns. */
+
+char *
+re_compile_pattern (pattern, size, bufp)
+     char *pattern;
+     size_t size;
+     struct re_pattern_buffer *bufp;
+{
+  register char *b = bufp->buffer;
+  register char *p = pattern;
+  char *pend = pattern + size;
+  register unsigned c, c1;
+  char *p0;
+  unsigned char *translate = (unsigned char *) bufp->translate;
+
+  /* Address of the count-byte of the most recently inserted `exactn'
+     command.  This makes it possible to tell whether a new exact-match
+     character can be added to that command or requires a new `exactn'
+     command.  */
+     
+  char *pending_exact = 0;
+
+  /* Address of the place where a forward-jump should go to the end of
+     the containing expression.  Each alternative of an `or', except the
+     last, ends with a forward-jump of this sort.  */
+
+  char *fixup_jump = 0;
+
+  /* Address of start of the most recently finished expression.
+     This tells postfix * where to find the start of its operand.  */
+
+  char *laststart = 0;
+
+  /* In processing a repeat, 1 means zero matches is allowed.  */
+
+  char zero_times_ok;
+
+  /* In processing a repeat, 1 means many matches is allowed.  */
+
+  char many_times_ok;
+
+  /* Address of beginning of regexp, or inside of last \(.  */
+
+  char *begalt = b;
+
+  /* In processing an interval, at least this many matches must be made.  */
+  int lower_bound;
+
+  /* In processing an interval, at most this many matches can be made.  */
+  int upper_bound;
+
+  /* Place in pattern (i.e., the {) to which to go back if the interval
+     is invalid.  */
+  char *beg_interval = 0;
+  
+  /* Stack of information saved by \( and restored by \).
+     Four stack elements are pushed by each \(:
+       First, the value of b.
+       Second, the value of fixup_jump.
+       Third, the value of regnum.
+       Fourth, the value of begalt.  */
+
+  int stackb[40];
+  int *stackp = stackb;
+  int *stacke = stackb + 40;
+  int *stackt;
+
+  /* Counts \('s as they are encountered.  Remembered for the matching \),
+     where it becomes the register number to put in the stop_memory
+     command.  */
+
+  int regnum = 1;
+
+  bufp->fastmap_accurate = 0;
+
+#ifndef emacs
+#ifndef SYNTAX_TABLE
+  /* Initialize the syntax table.  */
+   init_syntax_once();
+#endif
+#endif
+
+  if (bufp->allocated == 0)
+    {
+      bufp->allocated = INIT_BUF_SIZE;
+      if (bufp->buffer)
+	/* EXTEND_BUFFER loses when bufp->allocated is 0.  */
+	bufp->buffer = (char *) realloc (bufp->buffer, INIT_BUF_SIZE);
+      else
+	/* Caller did not allocate a buffer.  Do it for them.  */
+	bufp->buffer = (char *) malloc (INIT_BUF_SIZE);
+      if (!bufp->buffer) goto memory_exhausted;
+      begalt = b = bufp->buffer;
+    }
+
+  while (p != pend)
+    {
+      PATFETCH (c);
+
+      switch (c)
+	{
+	case '$':
+	  {
+	    char *p1 = p;
+	    /* When testing what follows the $,
+	       look past the \-constructs that don't consume anything.  */
+	    if (! (obscure_syntax & RE_CONTEXT_INDEP_OPS))
+	      while (p1 != pend)
+		{
+		  if (*p1 == '\\' && p1 + 1 != pend
+		      && (p1[1] == '<' || p1[1] == '>'
+			  || p1[1] == '`' || p1[1] == '\''
+#ifdef emacs
+			  || p1[1] == '='
+#endif
+			  || p1[1] == 'b' || p1[1] == 'B'))
+		    p1 += 2;
+		  else
+		    break;
+		}
+            if (obscure_syntax & RE_TIGHT_VBAR)
+	      {
+		if (! (obscure_syntax & RE_CONTEXT_INDEP_OPS) && p1 != pend)
+		  goto normal_char;
+		/* Make operand of last vbar end before this `$'.  */
+		if (fixup_jump)
+		  store_jump (fixup_jump, jump, b);
+		fixup_jump = 0;
+		BUFPUSH (endline);
+		break;
+	      }
+	    /* $ means succeed if at end of line, but only in special contexts.
+	      If validly in the middle of a pattern, it is a normal character. */
+
+            if ((obscure_syntax & RE_CONTEXTUAL_INVALID_OPS) && p1 != pend)
+	      goto invalid_pattern;
+	    if (p1 == pend || *p1 == '\n'
+		|| (obscure_syntax & RE_CONTEXT_INDEP_OPS)
+		|| (obscure_syntax & RE_NO_BK_PARENS
+		    ? *p1 == ')'
+		    : *p1 == '\\' && p1[1] == ')')
+		|| (obscure_syntax & RE_NO_BK_VBAR
+		    ? *p1 == '|'
+		    : *p1 == '\\' && p1[1] == '|'))
+	      {
+		BUFPUSH (endline);
+		break;
+	      }
+	    goto normal_char;
+          }
+	case '^':
+	  /* ^ means succeed if at beg of line, but only if no preceding 
+             pattern.  */
+             
+          if ((obscure_syntax & RE_CONTEXTUAL_INVALID_OPS) && laststart)
+            goto invalid_pattern;
+          if (laststart && p - 2 >= pattern && p[-2] != '\n'
+	       && !(obscure_syntax & RE_CONTEXT_INDEP_OPS))
+	    goto normal_char;
+	  if (obscure_syntax & RE_TIGHT_VBAR)
+	    {
+	      if (p != pattern + 1
+		  && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS))
+		goto normal_char;
+	      BUFPUSH (begline);
+	      begalt = b;
+	    }
+	  else
+	    BUFPUSH (begline);
+	  break;
+
+	case '+':
+	case '?':
+	  if ((obscure_syntax & RE_BK_PLUS_QM)
+	      || (obscure_syntax & RE_LIMITED_OPS))
+	    goto normal_char;
+	handle_plus:
+	case '*':
+	  /* If there is no previous pattern, char not special. */
+	  if (!laststart)
+            {
+              if (obscure_syntax & RE_CONTEXTUAL_INVALID_OPS)
+                goto invalid_pattern;
+              else if (! (obscure_syntax & RE_CONTEXT_INDEP_OPS))
+		goto normal_char;
+            }
+	  /* If there is a sequence of repetition chars,
+	     collapse it down to just one.  */
+	  zero_times_ok = 0;
+	  many_times_ok = 0;
+	  while (1)
+	    {
+	      zero_times_ok |= c != '+';
+	      many_times_ok |= c != '?';
+	      if (p == pend)
+		break;
+	      PATFETCH (c);
+	      if (c == '*')
+		;
+	      else if (!(obscure_syntax & RE_BK_PLUS_QM)
+		       && (c == '+' || c == '?'))
+		;
+	      else if ((obscure_syntax & RE_BK_PLUS_QM)
+		       && c == '\\')
+		{
+		  /* int c1; */
+		  PATFETCH (c1);
+		  if (!(c1 == '+' || c1 == '?'))
+		    {
+		      PATUNFETCH;
+		      PATUNFETCH;
+		      break;
+		    }
+		  c = c1;
+		}
+	      else
+		{
+		  PATUNFETCH;
+		  break;
+		}
+	    }
+
+	  /* Star, etc. applied to an empty pattern is equivalent
+	     to an empty pattern.  */
+	  if (!laststart)  
+	    break;
+
+	  /* Now we know whether or not zero matches is allowed
+	     and also whether or not two or more matches is allowed.  */
+	  if (many_times_ok)
+	    {
+	      /* If more than one repetition is allowed, put in at the
+                 end a backward relative jump from b to before the next
+                 jump we're going to put in below (which jumps from
+                 laststart to after this jump).  */
+              GET_BUFFER_SPACE (3);
+	      store_jump (b, maybe_finalize_jump, laststart - 3);
+	      b += 3;  	/* Because store_jump put stuff here.  */
+	    }
+          /* On failure, jump from laststart to b + 3, which will be the
+             end of the buffer after this jump is inserted.  */
+          GET_BUFFER_SPACE (3);
+	  insert_jump (on_failure_jump, laststart, b + 3, b);
+	  pending_exact = 0;
+	  b += 3;
+	  if (!zero_times_ok)
+	    {
+	      /* At least one repetition is required, so insert a
+                 dummy-failure before the initial on-failure-jump
+                 instruction of the loop. This effects a skip over that
+                 instruction the first time we hit that loop.  */
+              GET_BUFFER_SPACE (6);
+              insert_jump (dummy_failure_jump, laststart, laststart + 6, b);
+	      b += 3;
+	    }
+	  break;
+
+	case '.':
+	  laststart = b;
+	  BUFPUSH (anychar);
+	  break;
+
+        case '[':
+          if (p == pend)
+            goto invalid_pattern;
+	  while (b - bufp->buffer
+		 > bufp->allocated - 3 - (1 << BYTEWIDTH) / BYTEWIDTH)
+	    EXTEND_BUFFER;
+
+	  laststart = b;
+	  if (*p == '^')
+	    {
+              BUFPUSH (charset_not); 
+              p++;
+            }
+	  else
+	    BUFPUSH (charset);
+	  p0 = p;
+
+	  BUFPUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
+	  /* Clear the whole map */
+	  memset (b, 0, (1 << BYTEWIDTH) / BYTEWIDTH);
+          
+	  if ((obscure_syntax & RE_HAT_NOT_NEWLINE) && b[-2] == charset_not)
+            SET_LIST_BIT ('\n');
+
+
+	  /* Read in characters and ranges, setting map bits.  */
+	  while (1)
+	    {
+	      /* Don't translate while fetching, in case it's a range bound.
+		 When we set the bit for the character, we translate it.  */
+	      PATFETCH_RAW (c);
+
+	      /* If set, \ escapes characters when inside [...].  */
+	      if ((obscure_syntax & RE_AWK_CLASS_HACK) && c == '\\')
+	        {
+	          PATFETCH(c1);
+                  SET_LIST_BIT (c1);
+	          continue;
+	        }
+              if (c == ']')
+                {
+                  if (p == p0 + 1)
+                    {
+		      /* If this is an empty bracket expression.  */
+                      if ((obscure_syntax & RE_NO_EMPTY_BRACKETS) 
+                          && p == pend)
+                        goto invalid_pattern;
+                    }
+                  else 
+		    /* Stop if this isn't merely a ] inside a bracket
+                       expression, but rather the end of a bracket
+                       expression.  */
+                    break;
+                }
+              /* Get a range.  */
+              if (p[0] == '-' && p[1] != ']')
+		{
+                  PATFETCH (c1);
+		  /* Don't translate the range bounds while fetching them.  */
+		  PATFETCH_RAW (c1);
+                  
+		  if ((obscure_syntax & RE_NO_EMPTY_RANGES) && c > c1)
+                    goto invalid_pattern;
+                    
+		  if ((obscure_syntax & RE_NO_HYPHEN_RANGE_END) 
+                      && c1 == '-' && *p != ']')
+                    goto invalid_pattern;
+                    
+                  while (c <= c1)
+		    {
+		      /* Translate each char that's in the range.  */
+		      if (translate)
+			SET_LIST_BIT (translate[c]);
+		      else
+			SET_LIST_BIT (c);
+                      c++;
+		    }
+                }
+	      else if ((obscure_syntax & RE_CHAR_CLASSES)
+			&&  c == '[' && p[0] == ':')
+                {
+		  /* Longest valid character class word has six characters.  */
+                  char str[CHAR_CLASS_MAX_LENGTH];
+		  PATFETCH (c);
+		  c1 = 0;
+		  /* If no ] at end.  */
+                  if (p == pend)
+                    goto invalid_pattern;
+		  while (1)
+		    {
+		      /* Don't translate the ``character class'' characters.  */
+                      PATFETCH_RAW (c);
+		      if (c == ':' || c == ']' || p == pend
+                          || c1 == CHAR_CLASS_MAX_LENGTH)
+		        break;
+		      str[c1++] = c;
+		    }
+		  str[c1] = '\0';
+		  if (p == pend 	
+		      || c == ']'	/* End of the bracket expression.  */
+                      || p[0] != ']'
+		      || p + 1 == pend
+                      || (strcmp (str, "alpha") != 0 
+                          && strcmp (str, "upper") != 0
+			  && strcmp (str, "lower") != 0 
+                          && strcmp (str, "digit") != 0
+			  && strcmp (str, "alnum") != 0 
+                          && strcmp (str, "xdigit") != 0
+			  && strcmp (str, "space") != 0 
+                          && strcmp (str, "print") != 0
+			  && strcmp (str, "punct") != 0 
+                          && strcmp (str, "graph") != 0
+			  && strcmp (str, "cntrl") != 0))
+		    {
+		       /* Undo the ending character, the letters, and leave 
+                          the leading : and [ (but set bits for them).  */
+                      c1++;
+		      while (c1--)    
+			PATUNFETCH;
+		      SET_LIST_BIT ('[');
+		      SET_LIST_BIT (':');
+	            }
+                  else
+                    {
+                      /* The ] at the end of the character class.  */
+                      PATFETCH (c);					
+                      if (c != ']')
+                        goto invalid_pattern;
+		      for (c = 0; c < (1 << BYTEWIDTH); c++)
+			{
+			  if ((strcmp (str, "alpha") == 0  && isalpha (c))
+			       || (strcmp (str, "upper") == 0  && isupper (c))
+			       || (strcmp (str, "lower") == 0  && islower (c))
+			       || (strcmp (str, "digit") == 0  && isdigit (c))
+			       || (strcmp (str, "alnum") == 0  && isalnum (c))
+			       || (strcmp (str, "xdigit") == 0  && isxdigit (c))
+			       || (strcmp (str, "space") == 0  && isspace (c))
+			       || (strcmp (str, "print") == 0  && isprint (c))
+			       || (strcmp (str, "punct") == 0  && ispunct (c))
+			       || (strcmp (str, "graph") == 0  && isgraph (c))
+			       || (strcmp (str, "cntrl") == 0  && iscntrl (c)))
+			    SET_LIST_BIT (c);
+			}
+		    }
+                }
+              else if (translate)
+		SET_LIST_BIT (translate[c]);
+	      else
+                SET_LIST_BIT (c);
+	    }
+
+          /* Discard any character set/class bitmap bytes that are all
+             0 at the end of the map. Decrement the map-length byte too.  */
+          while ((int) b[-1] > 0 && b[b[-1] - 1] == 0) 
+            b[-1]--; 
+          b += b[-1];
+          break;
+
+	case '(':
+	  if (! (obscure_syntax & RE_NO_BK_PARENS))
+	    goto normal_char;
+	  else
+	    goto handle_open;
+
+	case ')':
+	  if (! (obscure_syntax & RE_NO_BK_PARENS))
+	    goto normal_char;
+	  else
+	    goto handle_close;
+
+        case '\n':
+	  if (! (obscure_syntax & RE_NEWLINE_OR))
+	    goto normal_char;
+	  else
+	    goto handle_bar;
+
+	case '|':
+	  if ((obscure_syntax & RE_CONTEXTUAL_INVALID_OPS)
+              && (! laststart  ||  p == pend))
+	    goto invalid_pattern;
+          else if (! (obscure_syntax & RE_NO_BK_VBAR))
+	    goto normal_char;
+	  else
+	    goto handle_bar;
+
+	case '{':
+           if (! ((obscure_syntax & RE_NO_BK_CURLY_BRACES)
+                  && (obscure_syntax & RE_INTERVALS)))
+             goto normal_char;
+           else
+             goto handle_interval;
+             
+        case '\\':
+	  if (p == pend) goto invalid_pattern;
+	  PATFETCH_RAW (c);
+	  switch (c)
+	    {
+	    case '(':
+	      if (obscure_syntax & RE_NO_BK_PARENS)
+		goto normal_backsl;
+	    handle_open:
+	      if (stackp == stacke) goto nesting_too_deep;
+
+              /* Laststart should point to the start_memory that we are about
+                 to push (unless the pattern has RE_NREGS or more ('s).  */
+              *stackp++ = b - bufp->buffer;    
+	      if (regnum < RE_NREGS)
+	        {
+		  BUFPUSH (start_memory);
+		  BUFPUSH (regnum);
+	        }
+	      *stackp++ = fixup_jump ? fixup_jump - bufp->buffer + 1 : 0;
+	      *stackp++ = regnum++;
+	      *stackp++ = begalt - bufp->buffer;
+	      fixup_jump = 0;
+	      laststart = 0;
+	      begalt = b;
+	      break;
+
+	    case ')':
+	      if (obscure_syntax & RE_NO_BK_PARENS)
+		goto normal_backsl;
+	    handle_close:
+	      if (stackp == stackb) goto unmatched_close;
+	      begalt = *--stackp + bufp->buffer;
+	      if (fixup_jump)
+		store_jump (fixup_jump, jump, b);
+	      if (stackp[-1] < RE_NREGS)
+		{
+		  BUFPUSH (stop_memory);
+		  BUFPUSH (stackp[-1]);
+		}
+	      stackp -= 2;
+              fixup_jump = *stackp ? *stackp + bufp->buffer - 1 : 0;
+              laststart = *--stackp + bufp->buffer;
+	      break;
+
+	    case '|':
+              if ((obscure_syntax & RE_LIMITED_OPS)
+	          || (obscure_syntax & RE_NO_BK_VBAR))
+		goto normal_backsl;
+	    handle_bar:
+              if (obscure_syntax & RE_LIMITED_OPS)
+                goto normal_char;
+	      /* Insert before the previous alternative a jump which
+                 jumps to this alternative if the former fails.  */
+              GET_BUFFER_SPACE (6);
+              insert_jump (on_failure_jump, begalt, b + 6, b);
+	      pending_exact = 0;
+	      b += 3;
+	      /* The alternative before the previous alternative has a
+                 jump after it which gets executed if it gets matched.
+                 Adjust that jump so it will jump to the previous
+                 alternative's analogous jump (put in below, which in
+                 turn will jump to the next (if any) alternative's such
+                 jump, etc.).  The last such jump jumps to the correct
+                 final destination.  */
+              if (fixup_jump)
+		store_jump (fixup_jump, jump, b);
+                
+	      /* Leave space for a jump after previous alternative---to be 
+                 filled in later.  */
+              fixup_jump = b;
+              b += 3;
+
+              laststart = 0;
+	      begalt = b;
+	      break;
+
+            case '{': 
+              if (! (obscure_syntax & RE_INTERVALS)
+		  /* Let \{ be a literal.  */
+                  || ((obscure_syntax & RE_INTERVALS)
+                      && (obscure_syntax & RE_NO_BK_CURLY_BRACES))
+		  /* If it's the string "\{".  */
+		  || (p - 2 == pattern  &&  p == pend))
+                goto normal_backsl;
+            handle_interval:
+	      beg_interval = p - 1;		/* The {.  */
+              /* If there is no previous pattern, this isn't an interval.  */
+	      if (!laststart)
+	        {
+                  if (obscure_syntax & RE_CONTEXTUAL_INVALID_OPS)
+		    goto invalid_pattern;
+                  else
+                    goto normal_backsl;
+                }
+              /* It also isn't an interval if not preceded by an re
+                 matching a single character or subexpression, or if
+                 the current type of intervals can't handle back
+                 references and the previous thing is a back reference.  */
+              if (! (*laststart == anychar
+		     || *laststart == charset
+		     || *laststart == charset_not
+		     || *laststart == start_memory
+		     || (*laststart == exactn  &&  laststart[1] == 1)
+		     || (! (obscure_syntax & RE_NO_BK_REFS)
+                         && *laststart == duplicate)))
+                {
+                  if (obscure_syntax & RE_NO_BK_CURLY_BRACES)
+                    goto normal_char;
+                    
+		  /* Posix extended syntax is handled in previous
+                     statement; this is for Posix basic syntax.  */
+                  if (obscure_syntax & RE_INTERVALS)
+                    goto invalid_pattern;
+                    
+                  goto normal_backsl;
+		}
+              lower_bound = -1;			/* So can see if are set.  */
+	      upper_bound = -1;
+              GET_UNSIGNED_NUMBER (lower_bound);
+	      if (c == ',')
+		{
+		  GET_UNSIGNED_NUMBER (upper_bound);
+		  if (upper_bound < 0)
+		    upper_bound = RE_DUP_MAX;
+		}
+	      if (upper_bound < 0)
+		upper_bound = lower_bound;
+              if (! (obscure_syntax & RE_NO_BK_CURLY_BRACES)) 
+                {
+                  if (c != '\\')
+                    goto invalid_pattern;
+                  PATFETCH (c);
+                }
+	      if (c != '}' || lower_bound < 0 || upper_bound > RE_DUP_MAX
+		  || lower_bound > upper_bound 
+                  || ((obscure_syntax & RE_NO_BK_CURLY_BRACES) 
+		      && p != pend  && *p == '{')) 
+	        {
+		  if (obscure_syntax & RE_NO_BK_CURLY_BRACES)
+                    goto unfetch_interval;
+                  else
+                    goto invalid_pattern;
+		}
+
+	      /* If upper_bound is zero, don't want to succeed at all; 
+ 		 jump from laststart to b + 3, which will be the end of
+                 the buffer after this jump is inserted.  */
+                 
+               if (upper_bound == 0)
+                 {
+                   GET_BUFFER_SPACE (3);
+                   insert_jump (jump, laststart, b + 3, b);
+                   b += 3;
+                 }
+
+               /* Otherwise, after lower_bound number of succeeds, jump
+                  to after the jump_n which will be inserted at the end
+                  of the buffer, and insert that jump_n.  */
+               else 
+		 { /* Set to 5 if only one repetition is allowed and
+	              hence no jump_n is inserted at the current end of
+                      the buffer; then only space for the succeed_n is
+                      needed.  Otherwise, need space for both the
+                      succeed_n and the jump_n.  */
+                      
+                   unsigned slots_needed = upper_bound == 1 ? 5 : 10;
+                     
+                   GET_BUFFER_SPACE (slots_needed);
+                   /* Initialize the succeed_n to n, even though it will
+                      be set by its attendant set_number_at, because
+                      re_compile_fastmap will need to know it.  Jump to
+                      what the end of buffer will be after inserting
+                      this succeed_n and possibly appending a jump_n.  */
+                   insert_jump_n (succeed_n, laststart, b + slots_needed, 
+		                  b, lower_bound);
+                   b += 5; 	/* Just increment for the succeed_n here.  */
+
+		  /* More than one repetition is allowed, so put in at
+		     the end of the buffer a backward jump from b to the
+                     succeed_n we put in above.  By the time we've gotten
+                     to this jump when matching, we'll have matched once
+                     already, so jump back only upper_bound - 1 times.  */
+
+                   if (upper_bound > 1)
+                     {
+                       store_jump_n (b, jump_n, laststart, upper_bound - 1);
+                       b += 5;
+                       /* When hit this when matching, reset the
+                          preceding jump_n's n to upper_bound - 1.  */
+                       BUFPUSH (set_number_at);
+		       GET_BUFFER_SPACE (2);
+                       STORE_NUMBER_AND_INCR (b, -5);
+                       STORE_NUMBER_AND_INCR (b, upper_bound - 1);
+                     }
+		   /* When hit this when matching, set the succeed_n's n.  */
+                   GET_BUFFER_SPACE (5);
+		   insert_op_2 (set_number_at, laststart, b, 5, lower_bound);
+                   b += 5;
+                 }
+              pending_exact = 0;
+	      beg_interval = 0;
+              break;
+
+
+            unfetch_interval:
+	      /* If an invalid interval, match the characters as literals.  */
+	       if (beg_interval)
+                 p = beg_interval;
+  	       else
+                 {
+                   fprintf (stderr, 
+		      "regex: no interval beginning to which to backtrack.\n");
+		   exit (1);
+                 }
+                 
+               beg_interval = 0;
+               PATFETCH (c);		/* normal_char expects char in `c'.  */
+	       goto normal_char;
+	       break;
+
+#ifdef emacs
+	    case '=':
+	      BUFPUSH (at_dot);
+	      break;
+
+	    case 's':	
+	      laststart = b;
+	      BUFPUSH (syntaxspec);
+	      PATFETCH (c);
+	      BUFPUSH (syntax_spec_code[c]);
+	      break;
+
+	    case 'S':
+	      laststart = b;
+	      BUFPUSH (notsyntaxspec);
+	      PATFETCH (c);
+	      BUFPUSH (syntax_spec_code[c]);
+	      break;
+#endif /* emacs */
+
+	    case 'w':
+	      laststart = b;
+	      BUFPUSH (wordchar);
+	      break;
+
+	    case 'W':
+	      laststart = b;
+	      BUFPUSH (notwordchar);
+	      break;
+
+	    case '<':
+	      BUFPUSH (wordbeg);
+	      break;
+
+	    case '>':
+	      BUFPUSH (wordend);
+	      break;
+
+	    case 'b':
+	      BUFPUSH (wordbound);
+	      break;
+
+	    case 'B':
+	      BUFPUSH (notwordbound);
+	      break;
+
+	    case '`':
+	      BUFPUSH (begbuf);
+	      break;
+
+	    case '\'':
+	      BUFPUSH (endbuf);
+	      break;
+
+	    case '1':
+	    case '2':
+	    case '3':
+	    case '4':
+	    case '5':
+	    case '6':
+	    case '7':
+	    case '8':
+	    case '9':
+	      if (obscure_syntax & RE_NO_BK_REFS)
+                goto normal_char;
+              c1 = c - '0';
+	      if (c1 >= regnum)
+		{
+  		  if (obscure_syntax & RE_NO_EMPTY_BK_REF)
+                    goto invalid_pattern;
+                  else
+                    goto normal_char;
+                }
+              /* Can't back reference to a subexpression if inside of it.  */
+              for (stackt = stackp - 2;  stackt > stackb;  stackt -= 4)
+ 		if (*stackt == c1)
+		  goto normal_char;
+	      laststart = b;
+	      BUFPUSH (duplicate);
+	      BUFPUSH (c1);
+	      break;
+
+	    case '+':
+	    case '?':
+	      if (obscure_syntax & RE_BK_PLUS_QM)
+		goto handle_plus;
+	      else
+                goto normal_backsl;
+              break;
+
+            default:
+	    normal_backsl:
+	      /* You might think it would be useful for \ to mean
+		 not to translate; but if we don't translate it
+		 it will never match anything.  */
+	      if (translate) c = translate[c];
+	      goto normal_char;
+	    }
+	  break;
+
+	default:
+	normal_char:		/* Expects the character in `c'.  */
+	  if (!pending_exact || pending_exact + *pending_exact + 1 != b
+	      || *pending_exact == 0177 || *p == '*' || *p == '^'
+	      || ((obscure_syntax & RE_BK_PLUS_QM)
+		  ? *p == '\\' && (p[1] == '+' || p[1] == '?')
+		  : (*p == '+' || *p == '?'))
+	      || ((obscure_syntax & RE_INTERVALS) 
+                  && ((obscure_syntax & RE_NO_BK_CURLY_BRACES)
+		      ? *p == '{'
+                      : (p[0] == '\\' && p[1] == '{'))))
+	    {
+	      laststart = b;
+	      BUFPUSH (exactn);
+	      pending_exact = b;
+	      BUFPUSH (0);
+	    }
+	  BUFPUSH (c);
+	  (*pending_exact)++;
+	}
+    }
+
+  if (fixup_jump)
+    store_jump (fixup_jump, jump, b);
+
+  if (stackp != stackb) goto unmatched_open;
+
+  bufp->used = b - bufp->buffer;
+  return 0;
+
+ invalid_pattern:
+  return "Invalid regular expression";
+
+ unmatched_open:
+  return "Unmatched \\(";
+
+ unmatched_close:
+  return "Unmatched \\)";
+
+ end_of_pattern:
+  return "Premature end of regular expression";
+
+ nesting_too_deep:
+  return "Nesting too deep";
+
+ too_big:
+  return "Regular expression too big";
+
+ memory_exhausted:
+  return "Memory exhausted";
+}
+
+
+/* Store a jump of the form <OPCODE> <relative address>.
+   Store in the location FROM a jump operation to jump to relative
+   address FROM - TO.  OPCODE is the opcode to store.  */
+
+static void
+store_jump (from, opcode, to)
+     char *from, *to;
+     int opcode;
+{
+  from[0] = (char)opcode;
+  STORE_NUMBER(from + 1, to - (from + 3));
+}
+
+
+/* Open up space before char FROM, and insert there a jump to TO.
+   CURRENT_END gives the end of the storage not in use, so we know 
+   how much data to copy up. OP is the opcode of the jump to insert.
+
+   If you call this function, you must zero out pending_exact.  */
+
+static void
+insert_jump (op, from, to, current_end)
+     int op;
+     char *from, *to, *current_end;
+{
+  register char *pfrom = current_end;		/* Copy from here...  */
+  register char *pto = current_end + 3;		/* ...to here.  */
+
+  while (pfrom != from)			       
+    *--pto = *--pfrom;
+  store_jump (from, op, to);
+}
+
+
+/* Store a jump of the form <opcode> <relative address> <n> .
+
+   Store in the location FROM a jump operation to jump to relative
+   address FROM - TO.  OPCODE is the opcode to store, N is a number the
+   jump uses, say, to decide how many times to jump.
+   
+   If you call this function, you must zero out pending_exact.  */
+
+static void
+store_jump_n (from, opcode, to, n)
+     char *from, *to;
+     int opcode;
+     unsigned n;
+{
+  from[0] = (char)opcode;
+  STORE_NUMBER (from + 1, to - (from + 3));
+  STORE_NUMBER (from + 3, n);
+}
+
+
+/* Similar to insert_jump, but handles a jump which needs an extra
+   number to handle minimum and maximum cases.  Open up space at
+   location FROM, and insert there a jump to TO.  CURRENT_END gives the
+   end of the storage in use, so we know how much data to copy up. OP is
+   the opcode of the jump to insert.
+
+   If you call this function, you must zero out pending_exact.  */
+
+static void
+insert_jump_n (op, from, to, current_end, n)
+     int op;
+     char *from, *to, *current_end;
+     unsigned n;
+{
+  register char *pfrom = current_end;		/* Copy from here...  */
+  register char *pto = current_end + 5;		/* ...to here.  */
+
+  while (pfrom != from)			       
+    *--pto = *--pfrom;
+  store_jump_n (from, op, to, n);
+}
+
+
+/* Open up space at location THERE, and insert operation OP followed by
+   NUM_1 and NUM_2.  CURRENT_END gives the end of the storage in use, so
+   we know how much data to copy up.
+
+   If you call this function, you must zero out pending_exact.  */
+
+static void
+insert_op_2 (op, there, current_end, num_1, num_2)
+     int op;
+     char *there, *current_end;
+     int num_1, num_2;
+{
+  register char *pfrom = current_end;		/* Copy from here...  */
+  register char *pto = current_end + 5;		/* ...to here.  */
+
+  while (pfrom != there)			       
+    *--pto = *--pfrom;
+  
+  there[0] = (char)op;
+  STORE_NUMBER (there + 1, num_1);
+  STORE_NUMBER (there + 3, num_2);
+}
+
+
+
+/* Given a pattern, compute a fastmap from it.  The fastmap records
+   which of the (1 << BYTEWIDTH) possible characters can start a string
+   that matches the pattern.  This fastmap is used by re_search to skip
+   quickly over totally implausible text.
+
+   The caller must supply the address of a (1 << BYTEWIDTH)-byte data 
+   area as bufp->fastmap.
+   The other components of bufp describe the pattern to be used.  */
+
+void
+re_compile_fastmap (bufp)
+     struct re_pattern_buffer *bufp;
+{
+  unsigned char *pattern = (unsigned char *) bufp->buffer;
+  int size = bufp->used;
+  register char *fastmap = bufp->fastmap;
+  register unsigned char *p = pattern;
+  register unsigned char *pend = pattern + size;
+  register int j, k;
+  unsigned char *translate = (unsigned char *) bufp->translate;
+  unsigned is_a_succeed_n;
+
+#ifndef NO_ALLOCA
+  unsigned char *stackb[NFAILURES];
+  unsigned char **stackp = stackb;
+
+#else
+  unsigned char **stackb;
+  unsigned char **stackp;
+  stackb = (unsigned char **) malloc (NFAILURES * sizeof (unsigned char *));
+  stackp = stackb;
+
+#endif /* NO_ALLOCA */
+  memset (fastmap, 0, (1 << BYTEWIDTH));
+  bufp->fastmap_accurate = 1;
+  bufp->can_be_null = 0;
+      
+  while (p)
+    {
+      is_a_succeed_n = 0;
+      if (p == pend)
+	{
+	  bufp->can_be_null = 1;
+	  break;
+	}
+#ifdef SWITCH_ENUM_BUG
+      switch ((int) ((enum regexpcode) *p++))
+#else
+      switch ((enum regexpcode) *p++)
+#endif
+	{
+	case exactn:
+	  if (translate)
+	    fastmap[translate[p[1]]] = 1;
+	  else
+	    fastmap[p[1]] = 1;
+	  break;
+
+        case begline:
+        case before_dot:
+	case at_dot:
+	case after_dot:
+	case begbuf:
+	case endbuf:
+	case wordbound:
+	case notwordbound:
+	case wordbeg:
+	case wordend:
+          continue;
+
+	case endline:
+	  if (translate)
+	    fastmap[translate['\n']] = 1;
+	  else
+	    fastmap['\n'] = 1;
+            
+	  if (bufp->can_be_null != 1)
+	    bufp->can_be_null = 2;
+	  break;
+
+	case jump_n:
+        case finalize_jump:
+	case maybe_finalize_jump:
+	case jump:
+	case dummy_failure_jump:
+          EXTRACT_NUMBER_AND_INCR (j, p);
+	  p += j;	
+	  if (j > 0)
+	    continue;
+          /* Jump backward reached implies we just went through
+	     the body of a loop and matched nothing.
+	     Opcode jumped to should be an on_failure_jump.
+	     Just treat it like an ordinary jump.
+	     For a * loop, it has pushed its failure point already;
+	     If so, discard that as redundant.  */
+
+          if ((enum regexpcode) *p != on_failure_jump
+	      && (enum regexpcode) *p != succeed_n)
+	    continue;
+          p++;
+          EXTRACT_NUMBER_AND_INCR (j, p);
+          p += j;		
+          if (stackp != stackb && *stackp == p)
+            stackp--;
+          continue;
+	  
+        case on_failure_jump:
+	handle_on_failure_jump:
+          EXTRACT_NUMBER_AND_INCR (j, p);
+          *++stackp = p + j;
+	  if (is_a_succeed_n)
+            EXTRACT_NUMBER_AND_INCR (k, p);	/* Skip the n.  */
+	  continue;
+
+	case succeed_n:
+	  is_a_succeed_n = 1;
+          /* Get to the number of times to succeed.  */
+          p += 2;		
+	  /* Increment p past the n for when k != 0.  */
+          EXTRACT_NUMBER_AND_INCR (k, p);
+          if (k == 0)
+	    {
+              p -= 4;
+              goto handle_on_failure_jump;
+            }
+          continue;
+          
+	case set_number_at:
+          p += 4;
+          continue;
+
+        case start_memory:
+	case stop_memory:
+	  p++;
+	  continue;
+
+	case duplicate:
+	  bufp->can_be_null = 1;
+	  fastmap['\n'] = 1;
+	case anychar:
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (j != '\n')
+	      fastmap[j] = 1;
+	  if (bufp->can_be_null)
+	    {
+	      FREE_AND_RETURN_VOID(stackb);
+	    }
+	  /* Don't return; check the alternative paths
+	     so we can set can_be_null if appropriate.  */
+	  break;
+
+	case wordchar:
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (SYNTAX (j) == Sword)
+	      fastmap[j] = 1;
+	  break;
+
+	case notwordchar:
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (SYNTAX (j) != Sword)
+	      fastmap[j] = 1;
+	  break;
+
+#ifdef emacs
+	case syntaxspec:
+	  k = *p++;
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (SYNTAX (j) == (enum syntaxcode) k)
+	      fastmap[j] = 1;
+	  break;
+
+	case notsyntaxspec:
+	  k = *p++;
+	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+	    if (SYNTAX (j) != (enum syntaxcode) k)
+	      fastmap[j] = 1;
+	  break;
+
+#else /* not emacs */
+	case syntaxspec:
+	case notsyntaxspec:
+	  break;
+#endif /* not emacs */
+
+	case charset:
+	  for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
+	    if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
+	      {
+		if (translate)
+		  fastmap[translate[j]] = 1;
+		else
+		  fastmap[j] = 1;
+	      }
+	  break;
+
+	case charset_not:
+	  /* Chars beyond end of map must be allowed */
+	  for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
+	    if (translate)
+	      fastmap[translate[j]] = 1;
+	    else
+	      fastmap[j] = 1;
+
+	  for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
+	    if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
+	      {
+		if (translate)
+		  fastmap[translate[j]] = 1;
+		else
+		  fastmap[j] = 1;
+	      }
+	  break;
+
+	case unused:	/* pacify gcc -Wall */
+	  break;
+	}
+
+      /* Get here means we have successfully found the possible starting
+         characters of one path of the pattern.  We need not follow this
+         path any farther.  Instead, look at the next alternative
+         remembered in the stack.  */
+   if (stackp != stackb)
+	p = *stackp--;
+      else
+	break;
+    }
+   FREE_AND_RETURN_VOID(stackb);
+}
+
+
+
+/* Like re_search_2, below, but only one string is specified, and
+   doesn't let you say where to stop matching. */
+
+int
+re_search (pbufp, string, size, startpos, range, regs)
+     struct re_pattern_buffer *pbufp;
+     char *string;
+     int size, startpos, range;
+     struct re_registers *regs;
+{
+  return re_search_2 (pbufp, (char *) 0, 0, string, size, startpos, range, 
+		      regs, size);
+}
+
+
+/* Using the compiled pattern in PBUFP->buffer, first tries to match the
+   virtual concatenation of STRING1 and STRING2, starting first at index
+   STARTPOS, then at STARTPOS + 1, and so on.  RANGE is the number of
+   places to try before giving up.  If RANGE is negative, it searches
+   backwards, i.e., the starting positions tried are STARTPOS, STARTPOS
+   - 1, etc.  STRING1 and STRING2 are of SIZE1 and SIZE2, respectively.
+   In REGS, return the indices of the virtual concatenation of STRING1
+   and STRING2 that matched the entire PBUFP->buffer and its contained
+   subexpressions.  Do not consider matching one past the index MSTOP in
+   the virtual concatenation of STRING1 and STRING2.
+
+   The value returned is the position in the strings at which the match
+   was found, or -1 if no match was found, or -2 if error (such as
+   failure stack overflow).  */
+
+int
+re_search_2 (pbufp, string1, size1, string2, size2, startpos, range,
+	     regs, mstop)
+     struct re_pattern_buffer *pbufp;
+     char *string1, *string2;
+     int size1, size2;
+     int startpos;
+     register int range;
+     struct re_registers *regs;
+     int mstop;
+{
+  register char *fastmap = pbufp->fastmap;
+  register unsigned char *translate = (unsigned char *) pbufp->translate;
+  int total_size = size1 + size2;
+  int endpos = startpos + range;
+  int val;
+
+  /* Check for out-of-range starting position.  */
+  if (startpos < 0  ||  startpos > total_size)
+    return -1;
+    
+  /* Fix up range if it would eventually take startpos outside of the
+     virtual concatenation of string1 and string2.  */
+  if (endpos < -1)
+    range = -1 - startpos;
+  else if (endpos > total_size)
+    range = total_size - startpos;
+
+  /* Update the fastmap now if not correct already.  */
+  if (fastmap && !pbufp->fastmap_accurate)
+    re_compile_fastmap (pbufp);
+  
+  /* If the search isn't to be a backwards one, don't waste time in a
+     long search for a pattern that says it is anchored.  */
+  if (pbufp->used > 0 && (enum regexpcode) pbufp->buffer[0] == begbuf
+      && range > 0)
+    {
+      if (startpos > 0)
+	return -1;
+      else
+	range = 1;
+    }
+
+  while (1)
+    { 
+      /* If a fastmap is supplied, skip quickly over characters that
+         cannot possibly be the start of a match.  Note, however, that
+         if the pattern can possibly match the null string, we must
+         test it at each starting point so that we take the first null
+         string we get.  */
+
+      if (fastmap && startpos < total_size && pbufp->can_be_null != 1)
+	{
+	  if (range > 0)	/* Searching forwards.  */
+	    {
+	      register int lim = 0;
+	      register unsigned char *p;
+	      int irange = range;
+	      if (startpos < size1 && startpos + range >= size1)
+		lim = range - (size1 - startpos);
+
+	      p = ((unsigned char *)
+		   &(startpos >= size1 ? string2 - size1 : string1)[startpos]);
+
+              while (range > lim && !fastmap[translate 
+                                             ? translate[*p++]
+                                             : *p++])
+		    range--;
+	      startpos += irange - range;
+	    }
+	  else				/* Searching backwards.  */
+	    {
+	      register unsigned char c;
+
+              if (string1 == 0 || startpos >= size1)
+		c = string2[startpos - size1];
+	      else 
+		c = string1[startpos];
+
+              c &= 0xff;
+	      if (translate ? !fastmap[translate[c]] : !fastmap[c])
+		goto advance;
+	    }
+	}
+
+      if (range >= 0 && startpos == total_size
+	  && fastmap && pbufp->can_be_null == 0)
+	return -1;
+
+      val = re_match_2 (pbufp, string1, size1, string2, size2, startpos,
+			regs, mstop);
+      if (val >= 0)
+	return startpos;
+      if (val == -2)
+	return -2;
+
+#ifndef NO_ALLOCA
+#ifdef C_ALLOCA
+      alloca (0);
+#endif /* C_ALLOCA */
+
+#endif /* NO_ALLOCA */
+    advance:
+      if (!range) 
+        break;
+      else if (range > 0) 
+        {
+          range--; 
+          startpos++;
+        }
+      else
+        {
+          range++; 
+          startpos--;
+        }
+    }
+  return -1;
+}
+
+
+
+#ifndef emacs   /* emacs never uses this.  */
+int
+re_match (pbufp, string, size, pos, regs)
+     struct re_pattern_buffer *pbufp;
+     char *string;
+     int size, pos;
+     struct re_registers *regs;
+{
+  return re_match_2 (pbufp, (char *) 0, 0, string, size, pos, regs, size); 
+}
+#endif /* not emacs */
+
+
+/* The following are used for re_match_2, defined below:  */
+
+/* Roughly the maximum number of failure points on the stack.  Would be
+   exactly that if always pushed MAX_NUM_FAILURE_ITEMS each time we failed.  */
+   
+int re_max_failures = 2000;
+
+/* Routine used by re_match_2.  */
+/* static int memcmp_translate (); *//* already declared */
+
+
+/* Structure and accessing macros used in re_match_2:  */
+
+struct register_info
+{
+  unsigned is_active : 1;
+  unsigned matched_something : 1;
+};
+
+#define IS_ACTIVE(R)  ((R).is_active)
+#define MATCHED_SOMETHING(R)  ((R).matched_something)
+
+
+/* Macros used by re_match_2:  */
+
+
+/* I.e., regstart, regend, and reg_info.  */
+
+#define NUM_REG_ITEMS  3
+
+/* We push at most this many things on the stack whenever we
+   fail.  The `+ 2' refers to PATTERN_PLACE and STRING_PLACE, which are
+   arguments to the PUSH_FAILURE_POINT macro.  */
+
+#define MAX_NUM_FAILURE_ITEMS   (RE_NREGS * NUM_REG_ITEMS + 2)
+
+
+/* We push this many things on the stack whenever we fail.  */
+
+#define NUM_FAILURE_ITEMS  (last_used_reg * NUM_REG_ITEMS + 2)
+
+
+/* This pushes most of the information about the current state we will want
+   if we ever fail back to it.  */
+
+#define PUSH_FAILURE_POINT(pattern_place, string_place)			\
+  {									\
+    long last_used_reg, this_reg;					\
+									\
+    /* Find out how many registers are active or have been matched.	\
+       (Aside from register zero, which is only set at the end.)  */	\
+    for (last_used_reg = RE_NREGS - 1; last_used_reg > 0; last_used_reg--)\
+      if (regstart[last_used_reg] != (unsigned char *)(-1L))		\
+        break;								\
+									\
+    if (stacke - stackp < NUM_FAILURE_ITEMS)				\
+      {									\
+	unsigned char **stackx;						\
+	unsigned int len = stacke - stackb;				\
+	if (len > re_max_failures * MAX_NUM_FAILURE_ITEMS)		\
+	  {								\
+	    FREE_AND_RETURN(stackb,(-2));				\
+	  }								\
+									\
+        /* Roughly double the size of the stack.  */			\
+        stackx = DOUBLE_STACK(stackx,stackb,len);			\
+	/* Rearrange the pointers. */					\
+	stackp = stackx + (stackp - stackb);				\
+	stackb = stackx;						\
+	stacke = stackb + 2 * len;					\
+      }									\
+									\
+    /* Now push the info for each of those registers.  */		\
+    for (this_reg = 1; this_reg <= last_used_reg; this_reg++)		\
+      {									\
+        *stackp++ = regstart[this_reg];					\
+        *stackp++ = regend[this_reg];					\
+        *stackp++ = (unsigned char *) &reg_info[this_reg];		\
+      }									\
+									\
+    /* Push how many registers we saved.  */				\
+    *stackp++ = (unsigned char *) last_used_reg;			\
+									\
+    *stackp++ = pattern_place;                                          \
+    *stackp++ = string_place;                                           \
+  }
+  
+
+/* This pops what PUSH_FAILURE_POINT pushes.  */
+
+#define POP_FAILURE_POINT()						\
+  {									\
+    int temp;								\
+    stackp -= 2;		/* Remove failure points.  */		\
+    temp = (int) *--stackp;	/* How many regs pushed.  */	        \
+    temp *= NUM_REG_ITEMS;	/* How much to take off the stack.  */	\
+    stackp -= temp; 		/* Remove the register info.  */	\
+  }
+
+
+#define MATCHING_IN_FIRST_STRING  (dend == end_match_1)
+
+/* Is true if there is a first string and if PTR is pointing anywhere
+   inside it or just past the end.  */
+   
+#define IS_IN_FIRST_STRING(ptr) 					\
+	(size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
+
+/* Call before fetching a character with *d.  This switches over to
+   string2 if necessary.  */
+
+#define PREFETCH							\
+ while (d == dend)						    	\
+  {									\
+    /* end of string2 => fail.  */					\
+    if (dend == end_match_2) 						\
+      goto fail;							\
+    /* end of string1 => advance to string2.  */ 			\
+    d = string2;						        \
+    dend = end_match_2;							\
+  }
+
+
+/* Call this when have matched something; it sets `matched' flags for the
+   registers corresponding to the subexpressions of which we currently
+   are inside.  */
+#define SET_REGS_MATCHED 						\
+  { unsigned this_reg; 							\
+    for (this_reg = 0; this_reg < RE_NREGS; this_reg++) 		\
+      { 								\
+        if (IS_ACTIVE(reg_info[this_reg]))				\
+          MATCHED_SOMETHING(reg_info[this_reg]) = 1;			\
+        else								\
+          MATCHED_SOMETHING(reg_info[this_reg]) = 0;			\
+      } 								\
+  }
+
+/* Test if at very beginning or at very end of the virtual concatenation
+   of string1 and string2.  If there is only one string, we've put it in
+   string2.  */
+
+#define AT_STRINGS_BEG  (d == (size1 ? string1 : string2)  ||  !size2)
+#define AT_STRINGS_END  (d == end2)	
+
+#define AT_WORD_BOUNDARY						\
+  (AT_STRINGS_BEG || AT_STRINGS_END || IS_A_LETTER (d - 1) != IS_A_LETTER (d))
+
+/* We have two special cases to check for: 
+     1) if we're past the end of string1, we have to look at the first
+        character in string2;
+     2) if we're before the beginning of string2, we have to look at the
+        last character in string1; we assume there is a string1, so use
+        this in conjunction with AT_STRINGS_BEG.  */
+#define IS_A_LETTER(d)							\
+  (SYNTAX ((d) == end1 ? *string2 : (d) == string2 - 1 ? *(end1 - 1) : *(d))\
+   == Sword)
+
+
+/* Match the pattern described by PBUFP against the virtual
+   concatenation of STRING1 and STRING2, which are of SIZE1 and SIZE2,
+   respectively.  Start the match at index POS in the virtual
+   concatenation of STRING1 and STRING2.  In REGS, return the indices of
+   the virtual concatenation of STRING1 and STRING2 that matched the
+   entire PBUFP->buffer and its contained subexpressions.  Do not
+   consider matching one past the index MSTOP in the virtual
+   concatenation of STRING1 and STRING2.
+
+   If pbufp->fastmap is nonzero, then it had better be up to date.
+
+   The reason that the data to match are specified as two components
+   which are to be regarded as concatenated is so this function can be
+   used directly on the contents of an Emacs buffer.
+
+   -1 is returned if there is no match.  -2 is returned if there is an
+   error (such as match stack overflow).  Otherwise the value is the
+   length of the substring which was matched.  */
+
+int
+re_match_2 (pbufp, string1_arg, size1, string2_arg, size2, pos, regs, mstop)
+     struct re_pattern_buffer *pbufp;
+     char *string1_arg, *string2_arg;
+     int size1, size2;
+     int pos;
+     struct re_registers *regs;
+     int mstop;
+{
+  register unsigned char *p = (unsigned char *) pbufp->buffer;
+
+  /* Pointer to beyond end of buffer.  */
+  register unsigned char *pend = p + pbufp->used;
+
+  unsigned char *string1 = (unsigned char *) string1_arg;
+  unsigned char *string2 = (unsigned char *) string2_arg;
+  unsigned char *end1;		/* Just past end of first string.  */
+  unsigned char *end2;		/* Just past end of second string.  */
+
+  /* Pointers into string1 and string2, just past the last characters in
+     each to consider matching.  */
+  unsigned char *end_match_1, *end_match_2;
+
+  register unsigned char *d, *dend;
+  register int mcnt;			/* Multipurpose.  */
+  unsigned char *translate = (unsigned char *) pbufp->translate;
+  unsigned is_a_jump_n = 0;
+
+ /* Failure point stack.  Each place that can handle a failure further
+    down the line pushes a failure point on this stack.  It consists of
+    restart, regend, and reg_info for all registers corresponding to the
+    subexpressions we're currently inside, plus the number of such
+    registers, and, finally, two char *'s.  The first char * is where to
+    resume scanning the pattern; the second one is where to resume
+    scanning the strings.  If the latter is zero, the failure point is a
+    ``dummy''; if a failure happens and the failure point is a dummy, it
+    gets discarded and the next next one is tried.  */
+
+#ifndef NO_ALLOCA
+  unsigned char *initial_stack[MAX_NUM_FAILURE_ITEMS * NFAILURES];
+#endif
+  unsigned char **stackb;
+  unsigned char **stackp;
+  unsigned char **stacke;
+
+
+  /* Information on the contents of registers. These are pointers into
+     the input strings; they record just what was matched (on this
+     attempt) by a subexpression part of the pattern, that is, the
+     regnum-th regstart pointer points to where in the pattern we began
+     matching and the regnum-th regend points to right after where we
+     stopped matching the regnum-th subexpression.  (The zeroth register
+     keeps track of what the whole pattern matches.)  */
+     
+  unsigned char *regstart[RE_NREGS];
+  unsigned char *regend[RE_NREGS];
+
+  /* The is_active field of reg_info helps us keep track of which (possibly
+     nested) subexpressions we are currently in. The matched_something
+     field of reg_info[reg_num] helps us tell whether or not we have
+     matched any of the pattern so far this time through the reg_num-th
+     subexpression.  These two fields get reset each time through any
+     loop their register is in.  */
+
+  struct register_info reg_info[RE_NREGS];
+
+
+  /* The following record the register info as found in the above
+     variables when we find a match better than any we've seen before. 
+     This happens as we backtrack through the failure points, which in
+     turn happens only if we have not yet matched the entire string.  */
+
+  unsigned best_regs_set = 0;
+  unsigned char *best_regstart[RE_NREGS];
+  unsigned char *best_regend[RE_NREGS];
+
+  /* Initialize the stack. */
+#ifdef NO_ALLOCA
+  stackb = (unsigned char **) malloc (MAX_NUM_FAILURE_ITEMS * NFAILURES * sizeof (char *));
+#else
+  stackb = initial_stack;
+#endif
+  stackp = stackb;
+  stacke = &stackb[MAX_NUM_FAILURE_ITEMS * NFAILURES];
+
+#ifdef DEBUG_REGEX
+  fprintf (stderr, "Entering re_match_2(%s%s)\n", string1_arg, string2_arg);
+#endif
+
+  /* Initialize subexpression text positions to -1 to mark ones that no
+     \( or ( and \) or ) has been seen for. Also set all registers to
+     inactive and mark them as not having matched anything or ever
+     failed.  */
+  for (mcnt = 0; mcnt < RE_NREGS; mcnt++)
+    {
+      regstart[mcnt] = regend[mcnt] = (unsigned char *) (-1L);
+      IS_ACTIVE (reg_info[mcnt]) = 0;
+      MATCHED_SOMETHING (reg_info[mcnt]) = 0;
+    }
+  
+  if (regs)
+    for (mcnt = 0; mcnt < RE_NREGS; mcnt++)
+      regs->start[mcnt] = regs->end[mcnt] = -1;
+
+  /* Set up pointers to ends of strings.
+     Don't allow the second string to be empty unless both are empty.  */
+  if (size2 == 0)
+    {
+      string2 = string1;
+      size2 = size1;
+      string1 = 0;
+      size1 = 0;
+    }
+  end1 = string1 + size1;
+  end2 = string2 + size2;
+
+  /* Compute where to stop matching, within the two strings.  */
+  if (mstop <= size1)
+    {
+      end_match_1 = string1 + mstop;
+      end_match_2 = string2;
+    }
+  else
+    {
+      end_match_1 = end1;
+      end_match_2 = string2 + mstop - size1;
+    }
+
+  /* `p' scans through the pattern as `d' scans through the data. `dend'
+     is the end of the input string that `d' points within. `d' is
+     advanced into the following input string whenever necessary, but
+     this happens before fetching; therefore, at the beginning of the
+     loop, `d' can be pointing at the end of a string, but it cannot
+     equal string2.  */
+
+  if (size1 != 0 && pos <= size1)
+    d = string1 + pos, dend = end_match_1;
+  else
+    d = string2 + pos - size1, dend = end_match_2;
+
+
+  /* This loops over pattern commands.  It exits by returning from the
+     function if match is complete, or it drops through if match fails
+     at this starting point in the input data.  */
+
+  while (1)
+    {
+#ifdef DEBUG_REGEX
+      fprintf (stderr,
+	       "regex loop(%d):  matching 0x%02d\n",
+	       p - (unsigned char *) pbufp->buffer,
+	       *p);
+#endif
+      is_a_jump_n = 0;
+      /* End of pattern means we might have succeeded.  */
+      if (p == pend)
+	{
+	  /* If not end of string, try backtracking.  Otherwise done.  */
+          if (d != end_match_2)
+	    {
+              if (stackp != stackb)
+                {
+                  /* More failure points to try.  */
+
+                  unsigned in_same_string = 
+        	          	IS_IN_FIRST_STRING (best_regend[0]) 
+	        	        == MATCHING_IN_FIRST_STRING;
+
+                  /* If exceeds best match so far, save it.  */
+                  if (! best_regs_set
+                      || (in_same_string && d > best_regend[0])
+                      || (! in_same_string && ! MATCHING_IN_FIRST_STRING))
+                    {
+                      best_regs_set = 1;
+                      best_regend[0] = d;	/* Never use regstart[0].  */
+                      
+                      for (mcnt = 1; mcnt < RE_NREGS; mcnt++)
+                        {
+                          best_regstart[mcnt] = regstart[mcnt];
+                          best_regend[mcnt] = regend[mcnt];
+                        }
+                    }
+                  goto fail;	       
+                }
+              /* If no failure points, don't restore garbage.  */
+              else if (best_regs_set)   
+                {
+	      restore_best_regs:
+                  /* Restore best match.  */
+                  d = best_regend[0];
+                  
+		  for (mcnt = 0; mcnt < RE_NREGS; mcnt++)
+		    {
+		      regstart[mcnt] = best_regstart[mcnt];
+		      regend[mcnt] = best_regend[mcnt];
+		    }
+                }
+            }
+
+	  /* If caller wants register contents data back, convert it 
+	     to indices.  */
+	  if (regs)
+	    {
+	      regs->start[0] = pos;
+	      if (MATCHING_IN_FIRST_STRING)
+		regs->end[0] = d - string1;
+	      else
+		regs->end[0] = d - string2 + size1;
+	      for (mcnt = 1; mcnt < RE_NREGS; mcnt++)
+		{
+		  if (regend[mcnt] == (unsigned char *)(-1L))
+		    {
+		      regs->start[mcnt] = -1;
+		      regs->end[mcnt] = -1;
+		      continue;
+		    }
+		  if (IS_IN_FIRST_STRING (regstart[mcnt]))
+		    regs->start[mcnt] = regstart[mcnt] - string1;
+		  else
+		    regs->start[mcnt] = regstart[mcnt] - string2 + size1;
+                    
+		  if (IS_IN_FIRST_STRING (regend[mcnt]))
+		    regs->end[mcnt] = regend[mcnt] - string1;
+		  else
+		    regs->end[mcnt] = regend[mcnt] - string2 + size1;
+		}
+	    }
+	  FREE_AND_RETURN(stackb,
+			  (d - pos - (MATCHING_IN_FIRST_STRING ?
+				      string1 :
+				      string2 - size1)));
+        }
+
+      /* Otherwise match next pattern command.  */
+#ifdef SWITCH_ENUM_BUG
+      switch ((int) ((enum regexpcode) *p++))
+#else
+      switch ((enum regexpcode) *p++)
+#endif
+	{
+
+	/* \( [or `(', as appropriate] is represented by start_memory,
+           \) by stop_memory.  Both of those commands are followed by
+           a register number in the next byte.  The text matched
+           within the \( and \) is recorded under that number.  */
+	case start_memory:
+          regstart[*p] = d;
+          IS_ACTIVE (reg_info[*p]) = 1;
+          MATCHED_SOMETHING (reg_info[*p]) = 0;
+          p++;
+          break;
+
+	case stop_memory:
+          regend[*p] = d;
+          IS_ACTIVE (reg_info[*p]) = 0;
+
+          /* If just failed to match something this time around with a sub-
+	     expression that's in a loop, try to force exit from the loop.  */
+          if ((! MATCHED_SOMETHING (reg_info[*p])
+	       || (enum regexpcode) p[-3] == start_memory)
+	      && (p + 1) != pend)              
+            {
+	      register unsigned char *p2 = p + 1;
+              mcnt = 0;
+              switch (*p2++)
+                {
+                  case jump_n:
+		    is_a_jump_n = 1;
+                  case finalize_jump:
+		  case maybe_finalize_jump:
+		  case jump:
+		  case dummy_failure_jump:
+                    EXTRACT_NUMBER_AND_INCR (mcnt, p2);
+		    if (is_a_jump_n)
+		      p2 += 2;
+                    break;
+                }
+	      p2 += mcnt;
+        
+              /* If the next operation is a jump backwards in the pattern
+	         to an on_failure_jump, exit from the loop by forcing a
+                 failure after pushing on the stack the on_failure_jump's 
+                 jump in the pattern, and d.  */
+	      if (mcnt < 0 && (enum regexpcode) *p2++ == on_failure_jump)
+		{
+                  EXTRACT_NUMBER_AND_INCR (mcnt, p2);
+                  PUSH_FAILURE_POINT (p2 + mcnt, d);
+                  goto fail;
+                }
+            }
+          p++;
+          break;
+
+	/* \<digit> has been turned into a `duplicate' command which is
+           followed by the numeric value of <digit> as the register number.  */
+        case duplicate:
+	  {
+	    int regno = *p++;   /* Get which register to match against */
+	    register unsigned char *d2, *dend2;
+
+	    /* Where in input to try to start matching.  */
+            d2 = regstart[regno];
+            
+            /* Where to stop matching; if both the place to start and
+               the place to stop matching are in the same string, then
+               set to the place to stop, otherwise, for now have to use
+               the end of the first string.  */
+
+            dend2 = ((IS_IN_FIRST_STRING (regstart[regno]) 
+		      == IS_IN_FIRST_STRING (regend[regno]))
+		     ? regend[regno] : end_match_1);
+	    while (1)
+	      {
+		/* If necessary, advance to next segment in register
+                   contents.  */
+		while (d2 == dend2)
+		  {
+		    if (dend2 == end_match_2) break;
+		    if (dend2 == regend[regno]) break;
+		    d2 = string2, dend2 = regend[regno];  /* end of string1 => advance to string2. */
+		  }
+		/* At end of register contents => success */
+		if (d2 == dend2) break;
+
+		/* If necessary, advance to next segment in data.  */
+		PREFETCH;
+
+		/* How many characters left in this segment to match.  */
+		mcnt = dend - d;
+                
+		/* Want how many consecutive characters we can match in
+                   one shot, so, if necessary, adjust the count.  */
+                if (mcnt > dend2 - d2)
+		  mcnt = dend2 - d2;
+                  
+		/* Compare that many; failure if mismatch, else move
+                   past them.  */
+		if (translate 
+                    ? memcmp_translate (d, d2, mcnt, translate) 
+                    : memcmp ((char *)d, (char *)d2, mcnt))
+		  goto fail;
+		d += mcnt, d2 += mcnt;
+	      }
+	  }
+	  break;
+
+	case anychar:
+	  PREFETCH;	  /* Fetch a data character. */
+	  /* Match anything but a newline, maybe even a null.  */
+	  if ((translate ? translate[*d] : *d) == '\n'
+              || ((obscure_syntax & RE_DOT_NOT_NULL) 
+                  && (translate ? translate[*d] : *d) == '\000'))
+	    goto fail;
+	  SET_REGS_MATCHED;
+          d++;
+	  break;
+
+	case charset:
+	case charset_not:
+	  {
+	    int not = 0;	    /* Nonzero for charset_not.  */
+	    register int c;
+	    if (*(p - 1) == (unsigned char) charset_not)
+	      not = 1;
+
+	    PREFETCH;	    /* Fetch a data character. */
+
+	    if (translate)
+	      c = translate[*d];
+	    else
+	      c = *d;
+
+	    if (c < *p * BYTEWIDTH
+		&& p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+	      not = !not;
+
+	    p += 1 + *p;
+
+	    if (!not) goto fail;
+	    SET_REGS_MATCHED;
+            d++;
+	    break;
+	  }
+
+	case begline:
+          if ((size1 != 0 && d == string1)
+              || (size1 == 0 && size2 != 0 && d == string2)
+              || (d && d[-1] == '\n')
+              || (size1 == 0 && size2 == 0))
+            break;
+          else
+            goto fail;
+            
+	case endline:
+	  if (d == end2
+	      || (d == end1 ? (size2 == 0 || *string2 == '\n') : *d == '\n'))
+	    break;
+	  goto fail;
+
+	/* `or' constructs are handled by starting each alternative with
+           an on_failure_jump that points to the start of the next
+           alternative.  Each alternative except the last ends with a
+           jump to the joining point.  (Actually, each jump except for
+           the last one really jumps to the following jump, because
+           tensioning the jumps is a hassle.)  */
+
+	/* The start of a stupid repeat has an on_failure_jump that points
+	   past the end of the repeat text. This makes a failure point so 
+           that on failure to match a repetition, matching restarts past
+           as many repetitions have been found with no way to fail and
+           look for another one.  */
+
+	/* A smart repeat is similar but loops back to the on_failure_jump
+	   so that each repetition makes another failure point.  */
+
+	case on_failure_jump:
+        on_failure:
+          EXTRACT_NUMBER_AND_INCR (mcnt, p);
+          PUSH_FAILURE_POINT (p + mcnt, d);
+          break;
+
+	/* The end of a smart repeat has a maybe_finalize_jump back.
+	   Change it either to a finalize_jump or an ordinary jump.  */
+	case maybe_finalize_jump:
+          EXTRACT_NUMBER_AND_INCR (mcnt, p);
+	  {
+	    register unsigned char *p2 = p;
+	    /* Compare what follows with the beginning of the repeat.
+	       If we can establish that there is nothing that they would
+	       both match, we can change to finalize_jump.  */
+	    while (p2 + 1 != pend
+		   && (*p2 == (unsigned char) stop_memory
+		       || *p2 == (unsigned char) start_memory))
+	      p2 += 2;				/* Skip over reg number.  */
+	    if (p2 == pend)
+	      p[-3] = (unsigned char) finalize_jump;
+	    else if (*p2 == (unsigned char) exactn
+		     || *p2 == (unsigned char) endline)
+	      {
+		register int c = *p2 == (unsigned char) endline ? '\n' : p2[2];
+		register unsigned char *p1 = p + mcnt;
+		/* p1[0] ... p1[2] are an on_failure_jump.
+		   Examine what follows that.  */
+		if (p1[3] == (unsigned char) exactn && p1[5] != c)
+		  p[-3] = (unsigned char) finalize_jump;
+		else if (p1[3] == (unsigned char) charset
+			 || p1[3] == (unsigned char) charset_not)
+		  {
+		    int not = p1[3] == (unsigned char) charset_not;
+		    if (c < p1[4] * BYTEWIDTH
+			&& p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+		      not = !not;
+		    /* `not' is 1 if c would match.  */
+		    /* That means it is not safe to finalize.  */
+		    if (!not)
+		      p[-3] = (unsigned char) finalize_jump;
+		  }
+	      }
+	  }
+	  p -= 2;		/* Point at relative address again.  */
+	  if (p[-1] != (unsigned char) finalize_jump)
+	    {
+	      p[-1] = (unsigned char) jump;	
+	      goto nofinalize;
+	    }
+        /* Note fall through.  */
+
+	/* The end of a stupid repeat has a finalize_jump back to the
+           start, where another failure point will be made which will
+           point to after all the repetitions found so far.  */
+
+        /* Take off failure points put on by matching on_failure_jump 
+           because didn't fail.  Also remove the register information
+           put on by the on_failure_jump.  */
+        case finalize_jump:
+          POP_FAILURE_POINT ();
+        /* Note fall through.  */
+        
+	/* Jump without taking off any failure points.  */
+        case jump:
+	nofinalize:
+	  EXTRACT_NUMBER_AND_INCR (mcnt, p);
+	  p += mcnt;
+	  break;
+
+        case dummy_failure_jump:
+          /* Normally, the on_failure_jump pushes a failure point, which
+             then gets popped at finalize_jump.  We will end up at
+             finalize_jump, also, and with a pattern of, say, `a+', we
+             are skipping over the on_failure_jump, so we have to push
+             something meaningless for finalize_jump to pop.  */
+          PUSH_FAILURE_POINT (0, 0);
+          goto nofinalize;
+
+
+        /* Have to succeed matching what follows at least n times.  Then
+          just handle like an on_failure_jump.  */
+        case succeed_n: 
+          EXTRACT_NUMBER (mcnt, p + 2);
+          /* Originally, this is how many times we HAVE to succeed.  */
+          if (mcnt)
+            {
+               mcnt--;
+	       p += 2;
+               STORE_NUMBER_AND_INCR (p, mcnt);
+            }
+	  else if (mcnt == 0)
+            {
+	      p[2] = unused;
+              p[3] = unused;
+              goto on_failure;
+            }
+          else
+	    { 
+              fprintf (stderr, "regex: the succeed_n's n is not set.\n");
+              exit (1);
+	    }
+          break;
+        
+        case jump_n: 
+          EXTRACT_NUMBER (mcnt, p + 2);
+          /* Originally, this is how many times we CAN jump.  */
+          if (mcnt)
+            {
+               mcnt--;
+               STORE_NUMBER(p + 2, mcnt);
+	       goto nofinalize;	     /* Do the jump without taking off
+			                any failure points.  */
+            }
+          /* If don't have to jump any more, skip over the rest of command.  */
+	  else      
+	    p += 4;		     
+          break;
+        
+	case set_number_at:
+	  {
+  	    register unsigned char *p1;
+
+            EXTRACT_NUMBER_AND_INCR (mcnt, p);
+            p1 = p + mcnt;
+            EXTRACT_NUMBER_AND_INCR (mcnt, p);
+	    STORE_NUMBER (p1, mcnt);
+            break;
+          }
+
+        /* Ignore these.  Used to ignore the n of succeed_n's which
+           currently have n == 0.  */
+        case unused:
+          break;
+
+        case wordbound:
+	  if (AT_WORD_BOUNDARY)
+	    break;
+	  goto fail;
+
+	case notwordbound:
+	  if (AT_WORD_BOUNDARY)
+	    goto fail;
+	  break;
+
+	case wordbeg:
+	  if (IS_A_LETTER (d) && (!IS_A_LETTER (d - 1) || AT_STRINGS_BEG))
+	    break;
+	  goto fail;
+
+	case wordend:
+          /* Have to check if AT_STRINGS_BEG before looking at d - 1.  */
+	  if (!AT_STRINGS_BEG && IS_A_LETTER (d - 1) 
+              && (!IS_A_LETTER (d) || AT_STRINGS_END))
+	    break;
+	  goto fail;
+
+#ifdef emacs
+	case before_dot:
+	  if (PTR_CHAR_POS (d) >= point)
+	    goto fail;
+	  break;
+
+	case at_dot:
+	  if (PTR_CHAR_POS (d) != point)
+	    goto fail;
+	  break;
+
+	case after_dot:
+	  if (PTR_CHAR_POS (d) <= point)
+	    goto fail;
+	  break;
+
+	case wordchar:
+	  mcnt = (int) Sword;
+	  goto matchsyntax;
+
+	case syntaxspec:
+	  mcnt = *p++;
+	matchsyntax:
+	  PREFETCH;
+	  if (SYNTAX (*d++) != (enum syntaxcode) mcnt) goto fail;
+          SET_REGS_MATCHED;
+	  break;
+	  
+	case notwordchar:
+	  mcnt = (int) Sword;
+	  goto matchnotsyntax;
+
+	case notsyntaxspec:
+	  mcnt = *p++;
+	matchnotsyntax:
+	  PREFETCH;
+	  if (SYNTAX (*d++) == (enum syntaxcode) mcnt) goto fail;
+	  SET_REGS_MATCHED;
+          break;
+
+#else /* not emacs */
+
+	case wordchar:
+	  PREFETCH;
+          if (!IS_A_LETTER (d))
+            goto fail;
+	  SET_REGS_MATCHED;
+	  break;
+	  
+	case notwordchar:
+	  PREFETCH;
+	  if (IS_A_LETTER (d))
+            goto fail;
+          SET_REGS_MATCHED;
+	  break;
+
+	case before_dot:
+	case at_dot:
+	case after_dot:
+	case syntaxspec:
+	case notsyntaxspec:
+	  break;
+
+#endif /* not emacs */
+
+	case begbuf:
+          if (AT_STRINGS_BEG)
+            break;
+          goto fail;
+
+        case endbuf:
+	  if (AT_STRINGS_END)
+	    break;
+	  goto fail;
+
+	case exactn:
+	  /* Match the next few pattern characters exactly.
+	     mcnt is how many characters to match.  */
+	  mcnt = *p++;
+	  /* This is written out as an if-else so we don't waste time
+             testing `translate' inside the loop.  */
+          if (translate)
+	    {
+	      do
+		{
+		  PREFETCH;
+		  if (translate[*d++] != *p++) goto fail;
+		}
+	      while (--mcnt);
+	    }
+	  else
+	    {
+	      do
+		{
+		  PREFETCH;
+		  if (*d++ != *p++) goto fail;
+		}
+	      while (--mcnt);
+	    }
+	  SET_REGS_MATCHED;
+          break;
+	}
+      continue;  /* Successfully executed one pattern command; keep going.  */
+
+    /* Jump here if any matching operation fails. */
+    fail:
+      if (stackp != stackb)
+	/* A restart point is known.  Restart there and pop it. */
+	{
+          short last_used_reg, this_reg;
+          
+          /* If this failure point is from a dummy_failure_point, just
+             skip it.  */
+	  if (!stackp[-2])
+            {
+              POP_FAILURE_POINT ();
+              goto fail;
+            }
+
+          d = *--stackp;
+	  p = *--stackp;
+          if (d >= string1 && d <= end1)
+	    dend = end_match_1;
+          /* Restore register info.  */
+          last_used_reg = (long) *--stackp;
+          
+          /* Make the ones that weren't saved -1 or 0 again.  */
+          for (this_reg = RE_NREGS - 1; this_reg > last_used_reg; this_reg--)
+            {
+              regend[this_reg] = (unsigned char *) (-1L);
+              regstart[this_reg] = (unsigned char *) (-1L);
+              IS_ACTIVE (reg_info[this_reg]) = 0;
+              MATCHED_SOMETHING (reg_info[this_reg]) = 0;
+            }
+          
+          /* And restore the rest from the stack.  */
+          for ( ; this_reg > 0; this_reg--)
+            {
+              reg_info[this_reg] = *(struct register_info *) *--stackp;
+              regend[this_reg] = *--stackp;
+              regstart[this_reg] = *--stackp;
+            }
+	}
+      else
+        break;   /* Matching at this starting point really fails.  */
+    }
+
+  if (best_regs_set)
+    goto restore_best_regs;
+
+  FREE_AND_RETURN(stackb,(-1)); 	/* Failure to match.  */
+}
+
+
+static int
+memcmp_translate (s1, s2, len, translate)
+     unsigned char *s1, *s2;
+     register int len;
+     unsigned char *translate;
+{
+  register unsigned char *p1 = s1, *p2 = s2;
+  while (len)
+    {
+      if (translate [*p1++] != translate [*p2++]) return 1;
+      len--;
+    }
+  return 0;
+}
+
+
+
+/* Entry points compatible with 4.2 BSD regex library.  */
+
+#if !defined(emacs) && !defined(GAWK)
+
+static struct re_pattern_buffer re_comp_buf;
+
+char *
+re_comp (s)
+     char *s;
+{
+  if (!s)
+    {
+      if (!re_comp_buf.buffer)
+	return "No previous regular expression";
+      return 0;
+    }
+
+  if (!re_comp_buf.buffer)
+    {
+      if (!(re_comp_buf.buffer = (char *) malloc (200)))
+	return "Memory exhausted";
+      re_comp_buf.allocated = 200;
+      if (!(re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH)))
+	return "Memory exhausted";
+    }
+  return re_compile_pattern (s, strlen (s), &re_comp_buf);
+}
+
+int
+re_exec (s)
+     char *s;
+{
+  int len = strlen (s);
+  return 0 <= re_search (&re_comp_buf, s, len, 0, len,
+			 (struct re_registers *) 0);
+}
+#endif /* not emacs && not GAWK */
+
+
+
+#ifdef test
+
+#ifdef atarist
+long _stksize = 2L;  /* reserve memory for stack */
+#endif
+#include <stdio.h>
+
+/* Indexed by a character, gives the upper case equivalent of the
+   character.  */
+
+char upcase[0400] = 
+  { 000, 001, 002, 003, 004, 005, 006, 007,
+    010, 011, 012, 013, 014, 015, 016, 017,
+    020, 021, 022, 023, 024, 025, 026, 027,
+    030, 031, 032, 033, 034, 035, 036, 037,
+    040, 041, 042, 043, 044, 045, 046, 047,
+    050, 051, 052, 053, 054, 055, 056, 057,
+    060, 061, 062, 063, 064, 065, 066, 067,
+    070, 071, 072, 073, 074, 075, 076, 077,
+    0100, 0101, 0102, 0103, 0104, 0105, 0106, 0107,
+    0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117,
+    0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127,
+    0130, 0131, 0132, 0133, 0134, 0135, 0136, 0137,
+    0140, 0101, 0102, 0103, 0104, 0105, 0106, 0107,
+    0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117,
+    0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127,
+    0130, 0131, 0132, 0173, 0174, 0175, 0176, 0177,
+    0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207,
+    0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217,
+    0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227,
+    0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237,
+    0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247,
+    0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257,
+    0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267,
+    0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277,
+    0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307,
+    0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317,
+    0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327,
+    0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337,
+    0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347,
+    0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357,
+    0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367,
+    0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377
+  };
+
+#ifdef canned
+
+#include "tests.h"
+
+typedef enum { extended_test, basic_test } test_type;
+
+/* Use this to run the tests we've thought of.  */
+
+void
+main ()
+{
+  test_type t = extended_test;
+
+  if (t == basic_test)
+    {
+      printf ("Running basic tests:\n\n");
+      test_posix_basic ();
+    }
+  else if (t == extended_test)
+    {
+      printf ("Running extended tests:\n\n");
+      test_posix_extended (); 
+    }
+}
+
+#else /* not canned */
+
+/* Use this to run interactive tests.  */
+
+void
+main (argc, argv)
+     int argc;
+     char **argv;
+{
+  char pat[80];
+  struct re_pattern_buffer buf;
+  int i;
+  char c;
+  char fastmap[(1 << BYTEWIDTH)];
+
+  /* Allow a command argument to specify the style of syntax.  */
+  if (argc > 1)
+    obscure_syntax = atol (argv[1]);
+
+  buf.allocated = 40;
+  buf.buffer = (char *) malloc (buf.allocated);
+  buf.fastmap = fastmap;
+  buf.translate = upcase;
+
+  while (1)
+    {
+      gets (pat);
+
+      if (*pat)
+	{
+          re_compile_pattern (pat, strlen(pat), &buf);
+
+	  for (i = 0; i < buf.used; i++)
+	    printchar (buf.buffer[i]);
+
+	  putchar ('\n');
+
+	  printf ("%d allocated, %d used.\n", buf.allocated, buf.used);
+
+	  re_compile_fastmap (&buf);
+	  printf ("Allowed by fastmap: ");
+	  for (i = 0; i < (1 << BYTEWIDTH); i++)
+	    if (fastmap[i]) printchar (i);
+	  putchar ('\n');
+	}
+
+      gets (pat);	/* Now read the string to match against */
+
+      i = re_match (&buf, pat, strlen (pat), 0, 0);
+      printf ("Match value %d.\n", i);
+    }
+}
+
+#endif
+
+
+#ifdef NOTDEF
+print_buf (bufp)
+     struct re_pattern_buffer *bufp;
+{
+  int i;
+
+  printf ("buf is :\n----------------\n");
+  for (i = 0; i < bufp->used; i++)
+    printchar (bufp->buffer[i]);
+  
+  printf ("\n%d allocated, %d used.\n", bufp->allocated, bufp->used);
+  
+  printf ("Allowed by fastmap: ");
+  for (i = 0; i < (1 << BYTEWIDTH); i++)
+    if (bufp->fastmap[i])
+      printchar (i);
+  printf ("\nAllowed by translate: ");
+  if (bufp->translate)
+    for (i = 0; i < (1 << BYTEWIDTH); i++)
+      if (bufp->translate[i])
+	printchar (i);
+  printf ("\nfastmap is%s accurate\n", bufp->fastmap_accurate ? "" : "n't");
+  printf ("can %s be null\n----------", bufp->can_be_null ? "" : "not");
+}
+#endif /* NOTDEF */
+
+printchar (c)
+     char c;
+{
+  if (c < 040 || c >= 0177)
+    {
+      putchar ('\\');
+      putchar (((c >> 6) & 3) + '0');
+      putchar (((c >> 3) & 7) + '0');
+      putchar ((c & 7) + '0');
+    }
+  else
+    putchar (c);
+}
+
+error (string)
+     char *string;
+{
+  puts (string);
+  exit (1);
+}
+#endif /* test */
diff --git a/gnu/usr.bin/awk/regex.h b/gnu/usr.bin/awk/regex.h
new file mode 100644
index 000000000000..fce11c3a97dd
--- /dev/null
+++ b/gnu/usr.bin/awk/regex.h
@@ -0,0 +1,260 @@
+/* Definitions for data structures callers pass the regex library.
+
+   Copyright (C) 1985, 1989-90 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 1, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+
+#ifndef __REGEXP_LIBRARY
+#define __REGEXP_LIBRARY
+
+/* Define number of parens for which we record the beginnings and ends.
+   This affects how much space the `struct re_registers' type takes up.  */
+#ifndef RE_NREGS
+#define RE_NREGS 10
+#endif
+
+#define BYTEWIDTH 8
+
+
+/* Maximum number of duplicates an interval can allow.  */
+#ifndef RE_DUP_MAX
+#define RE_DUP_MAX  ((1 << 15) - 1) 
+#endif
+
+
+/* This defines the various regexp syntaxes.  */
+extern long obscure_syntax;
+
+
+/* The following bits are used in the obscure_syntax variable to choose among
+   alternative regexp syntaxes.  */
+
+/* If this bit is set, plain parentheses serve as grouping, and backslash
+     parentheses are needed for literal searching.
+   If not set, backslash-parentheses are grouping, and plain parentheses
+     are for literal searching.  */
+#define RE_NO_BK_PARENS	1L
+
+/* If this bit is set, plain | serves as the `or'-operator, and \| is a 
+     literal.
+   If not set, \| serves as the `or'-operator, and | is a literal.  */
+#define RE_NO_BK_VBAR (1L << 1)
+
+/* If this bit is not set, plain + or ? serves as an operator, and \+, \? are 
+     literals.
+   If set, \+, \? are operators and plain +, ? are literals.  */
+#define RE_BK_PLUS_QM (1L << 2)
+
+/* If this bit is set, | binds tighter than ^ or $.
+   If not set, the contrary.  */
+#define RE_TIGHT_VBAR (1L << 3)
+
+/* If this bit is set, then treat newline as an OR operator.
+   If not set, treat it as a normal character.  */
+#define RE_NEWLINE_OR (1L << 4)
+
+/* If this bit is set, then special characters may act as normal
+   characters in some contexts. Specifically, this applies to:
+	^ -- only special at the beginning, or after ( or |;
+	$ -- only special at the end, or before ) or |;
+	*, +, ? -- only special when not after the beginning, (, or |.
+   If this bit is not set, special characters (such as *, ^, and $)
+   always have their special meaning regardless of the surrounding
+   context.  */
+#define RE_CONTEXT_INDEP_OPS (1L << 5)
+
+/* If this bit is not set, then \ before anything inside [ and ] is taken as 
+     a real \.
+   If set, then such a \ escapes the following character.  This is a
+     special case for awk.  */
+#define RE_AWK_CLASS_HACK (1L << 6)
+
+/* If this bit is set, then \{ and \} or { and } serve as interval operators.
+   If not set, then \{ and \} and { and } are treated as literals.  */
+#define RE_INTERVALS (1L << 7)
+
+/* If this bit is not set, then \{ and \} serve as interval operators and 
+     { and } are literals.
+   If set, then { and } serve as interval operators and \{ and \} are 
+     literals.  */
+#define RE_NO_BK_CURLY_BRACES (1L << 8)
+
+/* If this bit is set, then character classes are supported; they are:
+     [:alpha:],	[:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
+     [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
+   If not set, then character classes are not supported.  */
+#define RE_CHAR_CLASSES (1L << 9)
+
+/* If this bit is set, then the dot re doesn't match a null byte.
+   If not set, it does.  */
+#define RE_DOT_NOT_NULL (1L << 10)
+
+/* If this bit is set, then [^...] doesn't match a newline.
+   If not set, it does.  */
+#define RE_HAT_NOT_NEWLINE (1L << 11)
+
+/* If this bit is set, back references are recognized.
+   If not set, they aren't.  */
+#define RE_NO_BK_REFS (1L << 12)
+
+/* If this bit is set, back references must refer to a preceding
+   subexpression.  If not set, a back reference to a nonexistent
+   subexpression is treated as literal characters.  */
+#define RE_NO_EMPTY_BK_REF (1L << 13)
+
+/* If this bit is set, bracket expressions can't be empty.  
+   If it is set, they can be empty.  */
+#define RE_NO_EMPTY_BRACKETS (1L << 14)
+
+/* If this bit is set, then *, +, ? and { cannot be first in an re or
+   immediately after a |, or a (.  Furthermore, a | cannot be first or
+   last in an re, or immediately follow another | or a (.  Also, a ^
+   cannot appear in a nonleading position and a $ cannot appear in a
+   nontrailing position (outside of bracket expressions, that is).  */
+#define RE_CONTEXTUAL_INVALID_OPS (1L << 15)
+
+/* If this bit is set, then +, ? and | aren't recognized as operators.
+   If it's not, they are.  */
+#define RE_LIMITED_OPS (1L << 16)
+
+/* If this bit is set, then an ending range point has to collate higher
+     or equal to the starting range point.
+   If it's not set, then when the ending range point collates higher
+     than the starting range point, the range is just considered empty.  */
+#define RE_NO_EMPTY_RANGES (1L << 17)
+
+/* If this bit is set, then a hyphen (-) can't be an ending range point.
+   If it isn't, then it can.  */
+#define RE_NO_HYPHEN_RANGE_END (1L << 18)
+
+
+/* Define combinations of bits for the standard possibilities.  */
+#define RE_SYNTAX_POSIX_AWK (RE_NO_BK_PARENS | RE_NO_BK_VBAR \
+			| RE_CONTEXT_INDEP_OPS)
+#define RE_SYNTAX_AWK (RE_NO_BK_PARENS | RE_NO_BK_VBAR | RE_AWK_CLASS_HACK)
+#define RE_SYNTAX_EGREP (RE_NO_BK_PARENS | RE_NO_BK_VBAR \
+			| RE_CONTEXT_INDEP_OPS | RE_NEWLINE_OR)
+#define RE_SYNTAX_GREP (RE_BK_PLUS_QM | RE_NEWLINE_OR)
+#define RE_SYNTAX_EMACS 0
+#define RE_SYNTAX_POSIX_BASIC (RE_INTERVALS | RE_BK_PLUS_QM 		\
+			| RE_CHAR_CLASSES | RE_DOT_NOT_NULL 		\
+                        | RE_HAT_NOT_NEWLINE | RE_NO_EMPTY_BK_REF 	\
+                        | RE_NO_EMPTY_BRACKETS | RE_LIMITED_OPS		\
+                        | RE_NO_EMPTY_RANGES | RE_NO_HYPHEN_RANGE_END)	
+                        
+#define RE_SYNTAX_POSIX_EXTENDED (RE_INTERVALS | RE_NO_BK_CURLY_BRACES	   \
+			| RE_NO_BK_VBAR | RE_NO_BK_PARENS 		   \
+                        | RE_HAT_NOT_NEWLINE | RE_CHAR_CLASSES 		   \
+                        | RE_NO_EMPTY_BRACKETS | RE_CONTEXTUAL_INVALID_OPS \
+                        | RE_NO_BK_REFS | RE_NO_EMPTY_RANGES 		   \
+                        | RE_NO_HYPHEN_RANGE_END)
+
+
+/* This data structure is used to represent a compiled pattern.  */
+
+struct re_pattern_buffer
+  {
+    char *buffer;	/* Space holding the compiled pattern commands.  */
+    long allocated;	/* Size of space that `buffer' points to. */
+    long used;		/* Length of portion of buffer actually occupied  */
+    char *fastmap;	/* Pointer to fastmap, if any, or zero if none.  */
+			/* re_search uses the fastmap, if there is one,
+			   to skip over totally implausible characters.  */
+    char *translate;	/* Translate table to apply to all characters before 
+		           comparing, or zero for no translation.
+			   The translation is applied to a pattern when it is 
+                           compiled and to data when it is matched.  */
+    char fastmap_accurate;
+			/* Set to zero when a new pattern is stored,
+			   set to one when the fastmap is updated from it.  */
+    char can_be_null;   /* Set to one by compiling fastmap
+			   if this pattern might match the null string.
+			   It does not necessarily match the null string
+			   in that case, but if this is zero, it cannot.
+			   2 as value means can match null string
+			   but at end of range or before a character
+			   listed in the fastmap.  */
+  };
+
+
+/* search.c (search_buffer) needs this one value.  It is defined both in
+   regex.c and here.  */
+#define RE_EXACTN_VALUE 1
+
+
+/* Structure to store register contents data in.
+
+   Pass the address of such a structure as an argument to re_match, etc.,
+   if you want this information back.
+
+   For i from 1 to RE_NREGS - 1, start[i] records the starting index in
+   the string of where the ith subexpression matched, and end[i] records
+   one after the ending index.  start[0] and end[0] are analogous, for
+   the entire pattern.  */
+
+struct re_registers
+  {
+    int start[RE_NREGS];
+    int end[RE_NREGS];
+  };
+
+
+
+#ifdef __STDC__
+
+extern char *re_compile_pattern (char *, size_t, struct re_pattern_buffer *);
+/* Is this really advertised?  */
+extern void re_compile_fastmap (struct re_pattern_buffer *);
+extern int re_search (struct re_pattern_buffer *, char*, int, int, int,
+		      struct re_registers *);
+extern int re_search_2 (struct re_pattern_buffer *, char *, int,
+			char *, int, int, int,
+			struct re_registers *, int);
+extern int re_match (struct re_pattern_buffer *, char *, int, int,
+		     struct re_registers *);
+extern int re_match_2 (struct re_pattern_buffer *, char *, int,
+		       char *, int, int, struct re_registers *, int);
+extern long re_set_syntax (long syntax);
+
+#ifndef GAWK
+/* 4.2 bsd compatibility.  */
+extern char *re_comp (char *);
+extern int re_exec (char *);
+#endif
+
+#else /* !__STDC__ */
+
+extern char *re_compile_pattern ();
+/* Is this really advertised? */
+extern void re_compile_fastmap ();
+extern int re_search (), re_search_2 ();
+extern int re_match (), re_match_2 ();
+extern long re_set_syntax();
+
+#ifndef GAWK
+/* 4.2 bsd compatibility.  */
+extern char *re_comp ();
+extern int re_exec ();
+#endif
+
+#endif /* __STDC__ */
+
+
+#ifdef SYNTAX_TABLE
+extern char *re_syntax_table;
+#endif
+
+#endif /* !__REGEXP_LIBRARY */
diff --git a/gnu/usr.bin/awk/version.c b/gnu/usr.bin/awk/version.c
new file mode 100644
index 000000000000..adea5fafacfb
--- /dev/null
+++ b/gnu/usr.bin/awk/version.c
@@ -0,0 +1,46 @@
+char *version_string = "@(#)Gnu Awk (gawk) 2.15";
+
+/* 1.02		fixed /= += *= etc to return the new Left Hand Side instead
+		of the Right Hand Side */
+
+/* 1.03		Fixed split() to treat strings of space and tab as FS if
+		the split char is ' '.
+
+		Added -v option to print version number
+ 		
+		Fixed bug that caused rounding when printing large numbers  */
+
+/* 2.00beta	Incorporated the functionality of the "new" awk as described
+		the book (reference not handy).  Extensively tested, but no 
+		doubt still buggy.  Badly needs tuning and cleanup, in
+		particular in memory management which is currently almost
+		non-existent. */
+
+/* 2.01		JF:  Modified to compile under GCC, and fixed a few
+		bugs while I was at it.  I hope I didn't add any more.
+		I modified parse.y to reduce the number of reduce/reduce
+		conflicts.  There are still a few left. */
+
+/* 2.02		Fixed JF's bugs; improved memory management, still needs
+		lots of work. */
+
+/* 2.10		Major grammar rework and lots of bug fixes from David.
+		Major changes for performance enhancements from David.
+		A number of minor bug fixes and new features from Arnold.
+		Changes for MSDOS from Conrad Kwok and Scott Garfinkle.
+		The gawk.texinfo and info files included! */
+
+/* 2.11		Bug fix release to 2.10.  Lots of changes for portability,
+		speed, and configurability.  */
+
+/* 2.12		Lots of changes for portability, speed, and configurability.
+		Several bugs fixed.  POSIX compliance.  Removal of last set
+		of hard-wired limits.  Atari and VMS ports added. */
+
+/* 2.13		Public release of 2.12 */
+
+/* 2.14		Mostly bug fixes. */
+
+/* 2.15		Bug fixes plus intermixing of command-line source and files,
+		GNU long options, ARGIND, ERRNO and Plan 9 style /dev/ files. */
+