/* $OpenBSD: fmt.c,v 1.16 2000/06/25 15:35:42 pjanzen Exp $ */
/* Sensible version of fmt
*
* Syntax: fmt [ options ] [ goal [ max ] ] [ filename ... ]
*
* Since the documentation for the original fmt is so poor, here
* is an accurate description of what this one does. It's usually
* the same. The *mechanism* used may differ from that suggested
* here. Note that we are *not* entirely compatible with fmt,
* because fmt gets so many things wrong.
*
* 1. Tabs are expanded, assuming 8-space tab stops.
* If the `-t <n>' option is given, we assume <n>-space
* tab stops instead.
* Trailing blanks are removed from all lines.
* x\b == nothing, for any x other than \b.
* Other control characters are simply stripped. This
* includes \r.
* 2. Each line is split into leading whitespace and
* everything else. Maximal consecutive sequences of
* lines with the same leading whitespace are considered
* to form paragraphs, except that a blank line is always
* a paragraph to itself.
* If the `-p' option is given then the first line of a
* paragraph is permitted to have indentation different
* from that of the other lines.
* If the `-m' option is given then a line that looks
* like a mail message header, if it is not immediately
* preceded by a non-blank non-message-header line, is
* taken to start a new paragraph, which also contains
* any subsequent lines with non-empty leading whitespace.
* Unless the `-n' option is given, lines beginning with
* a . (dot) are not formatted.
* 3. The "everything else" is split into words; a word
* includes its trailing whitespace, and a word at the
* end of a line is deemed to be followed by a single
* space, or two spaces if it ends with a sentence-end
* character. (See the `-d' option for how to change that.)
* If the `-s' option has been given, then a word's trailing
* whitespace is replaced by what it would have had if it
* had occurred at end of line.
* 4. Each paragraph is sent to standard output as follows.
* We output the leading whitespace, and then enough words
* to make the line length as near as possible to the goal
* without exceeding the maximum. (If a single word would
* exceed the maximum, we output that anyway.) Of course
* the trailing whitespace of the last word is ignored.
* We then emit a newline and start again if there are any
* words left.
* Note that for a blank line this translates as "We emit
* a newline".
* If the `-l <n>' option is given, then leading whitespace
* is modified slightly: <n> spaces are replaced by a tab.
* Indented paragraphs (see above under `-p') make matters
* more complicated than this suggests. Actually every paragraph
* has two `leading whitespace' values; the value for the first
* line, and the value for the most recent line. (While processing
* the first line, the two are equal. When `-p' has not been
* given, they are always equal.) The leading whitespace
* actually output is that of the first line (for the first
* line of *output*) or that of the most recent line (for
* all other lines of output).
* When `-m' has been given, message header paragraphs are
* taken as having first-leading-whitespace empty and
* subsequent-leading-whitespace two spaces.
*
* Multiple input files are formatted one at a time, so that a file
* never ends in the middle of a line.
*
* There's an alternative mode of operation, invoked by giving
* the `-c' option. In that case we just center every line,
* and most of the other options are ignored. This should
* really be in a separate program, but we must stay compatible
* with old `fmt'.
*
* QUERY: Should `-m' also try to do the right thing with quoted text?
* QUERY: `-b' to treat backslashed whitespace as old `fmt' does?
* QUERY: Option meaning `never join lines'?
* QUERY: Option meaning `split in mid-word to avoid overlong lines'?
* (Those last two might not be useful, since we have `fold'.)
*
* Differences from old `fmt':
*
* - We have many more options. Options that aren't understood
* generate a lengthy usage message, rather than being
* treated as filenames.
* - Even with `-m', our handling of message headers is
* significantly different. (And much better.)
* - We don't treat `\ ' as non-word-breaking.
* - Downward changes of indentation start new paragraphs
* for us, as well as upward. (I think old `fmt' behaves
* in the way it does in order to allow indented paragraphs,
* but this is a broken way of making indented paragraphs
* behave right.)
* - Given the choice of going over or under |goal_length|
* by the same amount, we go over; old `fmt' goes under.
* - We treat `?' as ending a sentence, and not `:'. Old `fmt'
* does the reverse.
* - We return approved return codes. Old `fmt' returns
* 1 for some errors, and *the number of unopenable files*
* when that was all that went wrong.
* - We have fewer crashes and more helpful error messages.
* - We don't turn spaces into tabs at starts of lines unless
* specifically requested.
* - New `fmt' is somewhat smaller and slightly faster than
* old `fmt'.
*
* Bugs:
*
* None known. There probably are some, though.
*
* Portability:
*
* I believe this code to be pretty portable. It does require
* that you have `getopt'. If you need to include "getopt.h"
* for this (e.g., if your system didn't come with `getopt'
* and you installed it yourself) then you should arrange for
* NEED_getopt_h to be #defined.
*
* Everything here should work OK even on nasty 16-bit
* machines and nice 64-bit ones. However, it's only really
* been tested on my FreeBSD machine. Your mileage may vary.
*/
/* Copyright (c) 1997 Gareth McCaughan. All rights reserved.
*
* Redistribution and use of this code, in source or binary forms,
* with or without modification, are permitted subject to the following
* conditions:
*
* - Redistribution of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - If you distribute modified source code it must also include
* a notice saying that it has been modified, and giving a brief
* description of what changes have been made.
*
* Disclaimer: I am not responsible for the results of using this code.
* If it formats your hard disc, sends obscene messages to
* your boss and kills your children then that's your problem
* not mine. I give absolutely no warranty of any sort as to
* what the program will do, and absolutely refuse to be held
* liable for any consequences of your using it.
* Thank you. Have a nice day.
*/
/* RCS change log:
* Revision 1.5 1998/03/02 18:02:21 gjm11
* Minor changes for portability.
*
* Revision 1.4 1997/10/01 11:51:28 gjm11
* Repair broken indented-paragraph handling.
* Add mail message header stuff.
* Improve comments and layout.
* Make usable with non-BSD systems.
* Add revision display to usage message.
*
* Revision 1.3 1997/09/30 16:24:47 gjm11
* Add copyright notice, rcsid string and log message.
*
* Revision 1.2 1997/09/30 16:13:39 gjm11
* Add options: -d <chars>, -l <width>, -p, -s, -t <width>, -h .
* Parse options with `getopt'. Clean up code generally.
* Make comments more accurate.
*
* Revision 1.1 1997/09/30 11:29:57 gjm11
* Initial revision
*/
#ifndef lint
static const char copyright[] =
"Copyright (c) 1997 Gareth McCaughan. All rights reserved.\n";
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <ctype.h>
#include <err.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
/* Something that, we hope, will never be a genuine line length,
* indentation etc.
*/
#define SILLY ((size_t)-1)
/* I used to use |strtoul| for this, but (1) not all systems have it
* and (2) it's probably better to use |strtol| to detect negative
* numbers better.
* If |fussyp==0| then we don't complain about non-numbers
* (returning 0 instead), but we do complain about bad numbers.
*/
static size_t
get_positive(const char *s, const char *err_mess, int fussyP) {
char *t;
long result = strtol(s,&t,0);
if (*t) { if (fussyP) goto Lose; else return 0; }
if (result<=0) { Lose: errx(EX_USAGE, "%s", err_mess); }
return (size_t) result;
}
static size_t
get_nonnegative(const char *s, const char *err_mess, int fussyP) {
char *t;
long result = strtol(s,&t,0);
if (*t) { if (fussyP) goto Lose; else return 0; }
if (result<0) { Lose: errx(EX_USAGE, "%s", err_mess); }
return (size_t) result;
}
/* Global variables */
static int centerP=0; /* Try to center lines? */
static size_t goal_length=0; /* Target length for output lines */
static size_t max_length=0; /* Maximum length for output lines */
static int coalesce_spaces_P=0; /* Coalesce multiple whitespace -> ' ' ? */
static int allow_indented_paragraphs=0; /* Can first line have diff. ind.? */
static int tab_width=8; /* Number of spaces per tab stop */
static size_t output_tab_width=8; /* Ditto, when squashing leading spaces */
static const char *sentence_enders=".?!"; /* Double-space after these */
static int grok_mail_headers=0; /* treat embedded mail headers magically? */
static int format_troff=0; /* Format troff? */
static int n_errors=0; /* Number of failed files. Return on exit. */
static char *output_buffer=0; /* Output line will be built here */
static size_t x; /* Horizontal position in output line */
static size_t x0; /* Ditto, ignoring leading whitespace */
static size_t pending_spaces; /* Spaces to add before next word */
static int output_in_paragraph=0; /* Any of current para written out yet? */
/* Prototypes */
static void process_named_file (const char *);
static void process_stream (FILE *, const char *);
static size_t indent_length (const char *, size_t);
static int might_be_header (const unsigned char *);
static void new_paragraph (size_t, size_t);
static void output_word (size_t, size_t, const char *, size_t, size_t);
static void output_indent (size_t);
static void center_stream (FILE *, const char *);
static char * get_line (FILE *, size_t *);
static void * xrealloc (void *, size_t);
#define XMALLOC(x) xrealloc(0,x)
/* Here is perhaps the right place to mention that this code is
* all in top-down order. Hence, |main| comes first.
*/
int
main(int argc, char *argv[]) {
int ch; /* used for |getopt| processing */
(void) setlocale(LC_CTYPE, "");
/* 1. Grok parameters. */
while ((ch = getopt(argc, argv, "0123456789cd:hl:mnpst:w:")) != -1)
switch(ch) {
case 'c':
centerP = 1;
format_troff = 1;
continue;
case 'd':
sentence_enders = optarg;
continue;
case 'l':
output_tab_width
= get_nonnegative(optarg, "output tab width must be non-negative", 1);
continue;
case 'm':
grok_mail_headers = 1;
continue;
case 'n':
format_troff = 1;
continue;
case 'p':
allow_indented_paragraphs = 1;
continue;
case 's':
coalesce_spaces_P = 1;
continue;
case 't':
tab_width = get_positive(optarg, "tab width must be positive", 1);
continue;
case 'w':
goal_length = get_positive(optarg, "width must be positive", 1);
max_length = goal_length;
continue;
case '0': case '1': case '2': case '3': case '4': case '5':
case '6': case '7': case '8': case '9':
/* XXX this is not a stylistically approved use of getopt() */
if (goal_length==0) {
char *p;
p = argv[optind - 1];
if (p[0] == '-' && p[1] == ch && !p[2])
goal_length = get_positive(++p, "width must be nonzero", 1);
else
goal_length = get_positive(argv[optind]+1,
"width must be nonzero", 1);
max_length = goal_length;
}
continue;
case 'h': default:
fprintf(stderr,
"usage: fmt [-cmps] [-d chars] [-l num] [-t num]\n"
" [-w width | -width | goal [maximum]] [file ...]\n"
"Options: -c center each line instead of formatting\n"
" -d <chars> double-space after <chars> at line end\n"
" -l <n> turn each <n> spaces at start of line into a tab\n"
" -m try to make sure mail header lines stay separate\n"
" -n format lines beginning with a dot\n"
" -p allow indented paragraphs\n"
" -s coalesce whitespace inside lines\n"
" -t <n> have tabs every <n> columns\n"
" -w <n> set maximum width to <n>\n"
" goal set target width to goal\n");
exit(ch=='h' ? 0 : EX_USAGE);
}
argc -= optind; argv += optind;
/* [ goal [ maximum ] ] */
if (argc>0 && goal_length==0
&& (goal_length=get_positive(*argv,"goal length must be positive", 0))
!= 0) {
--argc; ++argv;
if (argc>0
&& (max_length=get_positive(*argv,"max length must be positive", 0))
!= 0) {
--argc; ++argv;
if (max_length<goal_length)
errx(EX_USAGE, "max length must be >= goal length");
}
}
if (goal_length==0) goal_length = 65;
if (max_length==0) max_length = goal_length+10;
output_buffer = XMALLOC(max_length+1); /* really needn't be longer */
/* 2. Process files. */
if (argc>0) {
while (argc-->0) process_named_file(*argv++);
}
else {
process_stream(stdin, "standard input");
}
/* We're done. */
return n_errors ? EX_NOINPUT : 0;
}
/* Process a single file, given its name.
*/
static void
process_named_file(const char *name) {
FILE *f=fopen(name, "r");
if (!f) { perror(name); ++n_errors; }
else {
process_stream(f, name);
fclose(f);
}
}
/* Types of mail header continuation lines:
*/
typedef enum {
hdr_ParagraphStart = -1,
hdr_NonHeader = 0,
hdr_Header = 1,
hdr_Continuation = 2
} HdrType;
/* Process a stream. This is where the real work happens,
* except that centering is handled separately.
*/
static void
process_stream(FILE *stream, const char *name) {
size_t last_indent=SILLY; /* how many spaces in last indent? */
size_t para_line_number=0; /* how many lines already read in this para? */
size_t first_indent=SILLY; /* indentation of line 0 of paragraph */
HdrType prev_header_type=hdr_ParagraphStart;
/* ^-- header_type of previous line; -1 at para start */
char *line;
size_t length;
if (centerP) { center_stream(stream, name); return; }
while ((line=get_line(stream,&length)) != NULL) {
size_t np=indent_length(line, length);
{ HdrType header_type=hdr_NonHeader;
if (grok_mail_headers && prev_header_type!=hdr_NonHeader) {
if (np==0 && might_be_header(line))
header_type = hdr_Header;
else if (np>0 && prev_header_type>hdr_NonHeader)
header_type = hdr_Continuation;
}
/* We need a new paragraph if and only if:
* this line is blank,
* OR it's a troff request (and we don't format troff),
* OR it's a mail header,
* OR it's not a mail header AND the last line was one,
* OR the indentation has changed
* AND the line isn't a mail header continuation line
* AND this isn't the second line of an indented paragraph.
*/
if ( length==0
|| (line[0]=='.' && !format_troff)
|| header_type==hdr_Header
|| (header_type==hdr_NonHeader && prev_header_type>hdr_NonHeader)
|| (np!=last_indent
&& header_type != hdr_Continuation
&& (!allow_indented_paragraphs || para_line_number != 1)) ) {
new_paragraph(output_in_paragraph ? last_indent : first_indent, np);
para_line_number = 0;
first_indent = np;
last_indent = np;
if (header_type==hdr_Header) last_indent=2; /* for cont. lines */
if (length==0 || (line[0]=='.' && !format_troff)) {
if (length==0)
putchar('\n');
else
printf("%.*s\n", (int)length, line);
prev_header_type=hdr_ParagraphStart;
continue;
}
}
else {
/* If this is an indented paragraph other than a mail header
* continuation, set |last_indent|.
*/
if (np != last_indent && header_type != hdr_Continuation)
last_indent=np;
}
prev_header_type = header_type;
}
{ size_t n=np;
while (n<length) {
/* Find word end and count spaces after it */
size_t word_length=0, space_length=0;
while (n+word_length < length && line[n+word_length] != ' ')
++word_length;
space_length = word_length;
while (n+space_length < length && line[n+space_length] == ' ')
++space_length;
/* Send the word to the output machinery. */
output_word(first_indent, last_indent,
line+n, word_length, space_length-word_length);
n += space_length;
}
}
++para_line_number;
}
new_paragraph(output_in_paragraph ? last_indent : first_indent, 0);
if (ferror(stream)) { perror(name); ++n_errors; }
}
/* How long is the indent on this line?
*/
static size_t
indent_length(const char *line, size_t length) {
size_t n=0;
while (n<length && *line++ == ' ') ++n;
return n;
}
/* Might this line be a mail header?
* We deem a line to be a possible header if it matches the
* Perl regexp /^[A-Z][-A-Za-z0-9]*:\s/. This is *not* the same
* as in RFC whatever-number-it-is; we want to be gratuitously
* conservative to avoid mangling ordinary civilised text.
*/
static int
might_be_header(const unsigned char *line) {
if (!isupper(*line++)) return 0;
while (*line && (isalnum(*line) || *line=='-')) ++line;
return (*line==':' && isspace(line[1]));
}
/* Begin a new paragraph with an indent of |indent| spaces.
*/
static void
new_paragraph(size_t old_indent, size_t indent) {
if (x0) {
if (old_indent>0) output_indent(old_indent);
fwrite(output_buffer, 1, x0, stdout);
putchar('\n');
}
x=indent; x0=0; pending_spaces=0;
output_in_paragraph = 0;
}
/* Output spaces or tabs for leading indentation.
*/
static void
output_indent(size_t n_spaces) {
if (output_tab_width) {
while (n_spaces >= output_tab_width) {
putchar('\t');
n_spaces -= output_tab_width;
}
}
while (n_spaces-- > 0) putchar(' ');
}
/* Output a single word, or add it to the buffer.
* indent0 and indent1 are the indents to use on the first and subsequent
* lines of a paragraph. They'll often be the same, of course.
*/
static void
output_word(size_t indent0, size_t indent1, const char *word, size_t length, size_t spaces) {
size_t new_x = x+pending_spaces+length;
size_t indent = output_in_paragraph ? indent1 : indent0;
/* If either |spaces==0| (at end of line) or |coalesce_spaces_P|
* (squashing internal whitespace), then add just one space;
* except that if the last character was a sentence-ender we
* actually add two spaces.
*/
if (coalesce_spaces_P || spaces==0)
spaces = strchr(sentence_enders, word[length-1]) ? 2 : 1;
if (new_x<=goal_length) {
/* After adding the word we still aren't at the goal length,
* so clearly we add it to the buffer rather than outputing it.
*/
memset(output_buffer+x0, ' ', pending_spaces);
x0 += pending_spaces; x += pending_spaces;
memcpy(output_buffer+x0, word, length);
x0 += length; x += length;
pending_spaces = spaces;
}
else {
/* Adding the word takes us past the goal. Print the line-so-far,
* and the word too iff either (1) the lsf is empty or (2) that
* makes us nearer the goal but doesn't take us over the limit,
* or (3) the word on its own takes us over the limit.
* In case (3) we put a newline in between.
*/
if (indent>0) output_indent(indent);
fwrite(output_buffer, 1, x0, stdout);
if (x0==0 || (new_x <= max_length && new_x-goal_length <= goal_length-x)) {
printf("%*s", (int)pending_spaces, "");
goto write_out_word;
}
else {
/* If the word takes us over the limit on its own, just
* spit it out and don't bother buffering it.
*/
if (indent+length > max_length) {
putchar('\n');
if (indent>0) output_indent(indent);
write_out_word:
fwrite(word, 1, length, stdout);
x0 = 0; x = indent1; pending_spaces = 0;
}
else {
memcpy(output_buffer, word, length);
x0 = length; x = length+indent1; pending_spaces = spaces;
}
}
putchar('\n');
output_in_paragraph = 1;
}
}
/* Process a stream, but just center its lines rather than trying to
* format them neatly.
*/
static void
center_stream(FILE *stream, const char *name) {
char *line;
size_t length;
while ((line=get_line(stream, &length)) != 0) {
size_t l=length;
while (l>0 && isspace(*line)) { ++line; --l; }
length=l;
while (l<goal_length) { putchar(' '); l+=2; }
fwrite(line, 1, length, stdout);
putchar('\n');
}
if (ferror(stream)) { perror(name); ++n_errors; }
}
/* Get a single line from a stream. Expand tabs, strip control
* characters and trailing whitespace, and handle backspaces.
* Return the address of the buffer containing the line, and
* put the length of the line in |lengthp|.
* This can cope with arbitrarily long lines, and with lines
* without terminating \n.
* If there are no characters left or an error happens, we
* return 0.
* Don't confuse |spaces_pending| here with the global
* |pending_spaces|.
*/
static char *
get_line(FILE *stream, size_t *lengthp) {
static char *buf=NULL;
static size_t length=0;
size_t len=0;
int ch;
size_t spaces_pending=0;
int troff=0;
if (buf==NULL) { length=100; buf=XMALLOC(length); }
while ((ch=getc(stream)) != '\n' && ch != EOF) {
if (len+spaces_pending==0 && ch=='.' && !format_troff) troff=1;
if (ch==' ') ++spaces_pending;
else if (troff || isprint(ch)) {
while (len+spaces_pending >= length) {
length*=2; buf=xrealloc(buf, length);
}
while (spaces_pending > 0) { --spaces_pending; buf[len++]=' '; }
buf[len++] = ch;
}
else if (ch=='\t')
spaces_pending += tab_width - (len+spaces_pending)%tab_width;
else if (ch=='\b') { if (len) --len; }
}
*lengthp=len;
return (len>0 || ch!=EOF) ? buf : 0;
}
/* (Re)allocate some memory, exiting with an error if we can't.
*/
static void *
xrealloc(void *ptr, size_t nbytes) {
void *p = realloc(ptr, nbytes);
if (p == NULL) errx(EX_OSERR, "out of memory");
return p;
}
