diff options
Diffstat (limited to 'usr.bin/look/look.1')
| -rw-r--r-- | usr.bin/look/look.1 | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/usr.bin/look/look.1 b/usr.bin/look/look.1 new file mode 100644 index 000000000000..7d0b74b43486 --- /dev/null +++ b/usr.bin/look/look.1 @@ -0,0 +1,152 @@ +.\" Copyright (c) 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.Dd December 29, 2020 +.Dt LOOK 1 +.Os +.Sh NAME +.Nm look +.Nd display lines beginning with a given string +.Sh SYNOPSIS +.Nm +.Op Fl df +.Op Fl t Ar termchar +.Ar string +.Op Ar +.Sh DESCRIPTION +The +.Nm +utility displays any lines in +.Ar file +which contain +.Ar string +as a prefix. +As +.Nm +performs a binary search, the lines in +.Ar file +must be sorted. +.Pp +If +.Ar file +is not specified, the file +.Pa /usr/share/dict/words +is used, only alphanumeric characters are compared and the case of +alphabetic characters is ignored. +.Pp +The following options are available: +.Bl -tag -width indent +.It Fl d , -alphanum +Dictionary character set and order, i.e., only alphanumeric characters +are compared. +.It Fl f , -ignore-case +Ignore the case of alphabetic characters. +.It Fl t , -terminate Ar termchar +Specify a string termination character, i.e., only the characters +in +.Ar string +up to and including the first occurrence of +.Ar termchar +are compared. +.El +.Sh ENVIRONMENT +The +.Ev LANG , LC_ALL +and +.Ev LC_CTYPE +environment variables affect the execution of the +.Nm +utility. +Their effect is described in +.Xr environ 7 . +.Sh FILES +.Bl -tag -width /usr/share/dict/words -compact +.It Pa /usr/share/dict/words +the dictionary +.El +.Sh EXIT STATUS +The +.Nm +utility exits 0 if one or more lines were found and displayed, +1 if no lines were found, and >1 if an error occurred. +.Sh EXAMPLES +Look for lines starting with +.Ql xylen +in the file +.Pa /usr/share/dict/words : +.Bd -literal -offset indent +$ look xylen +xylene +xylenol +xylenyl +.Ed +.Pp +Same as above, but do not consider any characters in +.Ar string +beyond the first +.Ql e . +Note that +.Fl f +is implicit since we are searching the default file +.Pa /usr/share/dict/words : +.Bd -literal -offset indent +$ look -t e xylen +Xyleborus +xylem +xylene +xylenol +xylenyl +xyletic +.Ed +.Sh COMPATIBILITY +The original manual page stated that tabs and blank characters participated +in comparisons when the +.Fl d +option was specified. +This was incorrect and the current man page matches the historic +implementation. +.Pp +The +.Fl a +and +.Fl -alternative +flags are ignored for compatibility. +.Sh SEE ALSO +.Xr grep 1 , +.Xr sort 1 +.Sh HISTORY +A +.Nm +utility appeared in +.At v7 . +.Sh BUGS +Lines are not compared according to the current locale's collating +order. +Input files must be sorted with +.Ev LC_COLLATE +set to +.Ql C . |