1 /* $OpenBSD: fmt.c,v 1.21 2004/04/01 23:14:19 tedu Exp $ */
3 /* Sensible version of fmt
5 * Syntax: fmt [ options ] [ goal [ max ] ] [ filename ... ]
7 * Since the documentation for the original fmt is so poor, here
8 * is an accurate description of what this one does. It's usually
9 * the same. The *mechanism* used may differ from that suggested
10 * here. Note that we are *not* entirely compatible with fmt,
11 * because fmt gets so many things wrong.
13 * 1. Tabs are expanded, assuming 8-space tab stops.
14 * If the `-t <n>' option is given, we assume <n>-space
16 * Trailing blanks are removed from all lines.
17 * x\b == nothing, for any x other than \b.
18 * Other control characters are simply stripped. This
20 * 2. Each line is split into leading whitespace and
21 * everything else. Maximal consecutive sequences of
22 * lines with the same leading whitespace are considered
23 * to form paragraphs, except that a blank line is always
24 * a paragraph to itself.
25 * If the `-p' option is given then the first line of a
26 * paragraph is permitted to have indentation different
27 * from that of the other lines.
28 * If the `-m' option is given then a line that looks
29 * like a mail message header, if it is not immediately
30 * preceded by a non-blank non-message-header line, is
31 * taken to start a new paragraph, which also contains
32 * any subsequent lines with non-empty leading whitespace.
33 * Unless the `-n' option is given, lines beginning with
34 * a . (dot) are not formatted.
35 * 3. The "everything else" is split into words; a word
36 * includes its trailing whitespace, and a word at the
37 * end of a line is deemed to be followed by a single
38 * space, or two spaces if it ends with a sentence-end
39 * character. (See the `-d' option for how to change that.)
40 * If the `-s' option has been given, then a word's trailing
41 * whitespace is replaced by what it would have had if it
42 * had occurred at end of line.
43 * 4. Each paragraph is sent to standard output as follows.
44 * We output the leading whitespace, and then enough words
45 * to make the line length as near as possible to the goal
46 * without exceeding the maximum. (If a single word would
47 * exceed the maximum, we output that anyway.) Of course
48 * the trailing whitespace of the last word is ignored.
49 * We then emit a newline and start again if there are any
51 * Note that for a blank line this translates as "We emit
53 * If the `-l <n>' option is given, then leading whitespace
54 * is modified slightly: <n> spaces are replaced by a tab.
55 * Indented paragraphs (see above under `-p') make matters
56 * more complicated than this suggests. Actually every paragraph
57 * has two `leading whitespace' values; the value for the first
58 * line, and the value for the most recent line. (While processing
59 * the first line, the two are equal. When `-p' has not been
60 * given, they are always equal.) The leading whitespace
61 * actually output is that of the first line (for the first
62 * line of *output*) or that of the most recent line (for
63 * all other lines of output).
64 * When `-m' has been given, message header paragraphs are
65 * taken as having first-leading-whitespace empty and
66 * subsequent-leading-whitespace two spaces.
68 * Multiple input files are formatted one at a time, so that a file
69 * never ends in the middle of a line.
71 * There's an alternative mode of operation, invoked by giving
72 * the `-c' option. In that case we just center every line,
73 * and most of the other options are ignored. This should
74 * really be in a separate program, but we must stay compatible
77 * QUERY: Should `-m' also try to do the right thing with quoted text?
78 * QUERY: `-b' to treat backslashed whitespace as old `fmt' does?
79 * QUERY: Option meaning `never join lines'?
80 * QUERY: Option meaning `split in mid-word to avoid overlong lines'?
81 * (Those last two might not be useful, since we have `fold'.)
83 * Differences from old `fmt':
85 * - We have many more options. Options that aren't understood
86 * generate a lengthy usage message, rather than being
87 * treated as filenames.
88 * - Even with `-m', our handling of message headers is
89 * significantly different. (And much better.)
90 * - We don't treat `\ ' as non-word-breaking.
91 * - Downward changes of indentation start new paragraphs
92 * for us, as well as upward. (I think old `fmt' behaves
93 * in the way it does in order to allow indented paragraphs,
94 * but this is a broken way of making indented paragraphs
96 * - Given the choice of going over or under |goal_length|
97 * by the same amount, we go over; old `fmt' goes under.
98 * - We treat `?' as ending a sentence, and not `:'. Old `fmt'
100 * - We return approved return codes. Old `fmt' returns
101 * 1 for some errors, and *the number of unopenable files*
102 * when that was all that went wrong.
103 * - We have fewer crashes and more helpful error messages.
104 * - We don't turn spaces into tabs at starts of lines unless
105 * specifically requested.
106 * - New `fmt' is somewhat smaller and slightly faster than
111 * None known. There probably are some, though.
115 * I believe this code to be pretty portable. It does require
116 * that you have `getopt'. If you need to include "getopt.h"
117 * for this (e.g., if your system didn't come with `getopt'
118 * and you installed it yourself) then you should arrange for
119 * NEED_getopt_h to be #defined.
121 * Everything here should work OK even on nasty 16-bit
122 * machines and nice 64-bit ones. However, it's only really
123 * been tested on my FreeBSD machine. Your mileage may vary.
126 /* Copyright (c) 1997 Gareth McCaughan. All rights reserved.
128 * Redistribution and use of this code, in source or binary forms,
129 * with or without modification, are permitted subject to the following
132 * - Redistribution of source code must retain the above copyright
133 * notice, this list of conditions and the following disclaimer.
135 * - If you distribute modified source code it must also include
136 * a notice saying that it has been modified, and giving a brief
137 * description of what changes have been made.
139 * Disclaimer: I am not responsible for the results of using this code.
140 * If it formats your hard disc, sends obscene messages to
141 * your boss and kills your children then that's your problem
142 * not mine. I give absolutely no warranty of any sort as to
143 * what the program will do, and absolutely refuse to be held
144 * liable for any consequences of your using it.
145 * Thank you. Have a nice day.
149 * Revision 1.5 1998/03/02 18:02:21 gjm11
150 * Minor changes for portability.
152 * Revision 1.4 1997/10/01 11:51:28 gjm11
153 * Repair broken indented-paragraph handling.
154 * Add mail message header stuff.
155 * Improve comments and layout.
156 * Make usable with non-BSD systems.
157 * Add revision display to usage message.
159 * Revision 1.3 1997/09/30 16:24:47 gjm11
160 * Add copyright notice, rcsid string and log message.
162 * Revision 1.2 1997/09/30 16:13:39 gjm11
163 * Add options: -d <chars>, -l <width>, -p, -s, -t <width>, -h .
164 * Parse options with `getopt'. Clean up code generally.
165 * Make comments more accurate.
167 * Revision 1.1 1997/09/30 11:29:57 gjm11
172 static const char copyright[] =
173 "Copyright (c) 1997 Gareth McCaughan. All rights reserved.\n";
174 #endif /* not lint */
175 #include <sys/cdefs.h>
176 __FBSDID("$FreeBSD$");
184 #include <sysexits.h>
189 /* Something that, we hope, will never be a genuine line length,
192 #define SILLY ((size_t)-1)
194 /* I used to use |strtoul| for this, but (1) not all systems have it
195 * and (2) it's probably better to use |strtol| to detect negative
197 * If |fussyp==0| then we don't complain about non-numbers
198 * (returning 0 instead), but we do complain about bad numbers.
201 get_positive(const char *s, const char *err_mess, int fussyP)
204 long result = strtol(s, &t, 0);
213 Lose: errx(EX_USAGE, "%s", err_mess);
215 return (size_t)result;
219 get_nonnegative(const char *s, const char *err_mess, int fussyP)
222 long result = strtol(s, &t, 0);
231 Lose: errx(EX_USAGE, "%s", err_mess);
233 return (size_t)result;
236 /* Global variables */
238 static int centerP = 0; /* Try to center lines? */
239 static size_t goal_length = 0; /* Target length for output lines */
240 static size_t max_length = 0; /* Maximum length for output lines */
241 static int coalesce_spaces_P = 0; /* Coalesce multiple whitespace -> ' ' ? */
242 static int allow_indented_paragraphs = 0; /* Can first line have diff. ind.? */
243 static int tab_width = 8; /* Number of spaces per tab stop */
244 static size_t output_tab_width = 8; /* Ditto, when squashing leading spaces */
245 static const wchar_t *sentence_enders = L".?!"; /* Double-space after these */
246 static int grok_mail_headers = 0; /* treat embedded mail headers magically? */
247 static int format_troff = 0; /* Format troff? */
249 static int n_errors = 0; /* Number of failed files. Return on exit. */
250 static wchar_t *output_buffer = NULL; /* Output line will be built here */
251 static size_t x; /* Horizontal position in output line */
252 static size_t x0; /* Ditto, ignoring leading whitespace */
253 static size_t output_buffer_length = 0;
254 static size_t pending_spaces; /* Spaces to add before next word */
255 static int output_in_paragraph = 0; /* Any of current para written out yet? */
259 static void process_named_file(const char *);
260 static void process_stream(FILE *, const char *);
261 static size_t indent_length(const wchar_t *, size_t);
262 static int might_be_header(const wchar_t *);
263 static void new_paragraph(size_t, size_t);
264 static void output_word(size_t, size_t, const wchar_t *, size_t, size_t);
265 static void output_indent(size_t);
266 static void center_stream(FILE *, const char *);
267 static wchar_t *get_line(FILE *, size_t *);
268 static void *xrealloc(void *, size_t);
270 #define XMALLOC(x) xrealloc(0,x)
272 /* Here is perhaps the right place to mention that this code is
273 * all in top-down order. Hence, |main| comes first.
276 main(int argc, char *argv[])
278 int ch; /* used for |getopt| processing */
283 (void)setlocale(LC_CTYPE, "");
285 /* 1. Grok parameters. */
287 while ((ch = getopt(argc, argv, "0123456789cd:hl:mnpst:w:")) != -1)
295 len = mbsrtowcs(NULL, &src, 0, NULL);
296 if (len == (size_t)-1)
297 err(EX_USAGE, "bad sentence-ending character set");
298 tmp = XMALLOC((len + 1) * sizeof(wchar_t));
299 mbsrtowcs(tmp, &src, len + 1, NULL);
300 sentence_enders = tmp;
304 = get_nonnegative(optarg, "output tab width must be non-negative", 1);
307 grok_mail_headers = 1;
313 allow_indented_paragraphs = 1;
316 coalesce_spaces_P = 1;
319 tab_width = get_positive(optarg, "tab width must be positive", 1);
322 goal_length = get_positive(optarg, "width must be positive", 1);
323 max_length = goal_length;
325 case '0': case '1': case '2': case '3': case '4': case '5':
326 case '6': case '7': case '8': case '9':
328 * XXX this is not a stylistically approved use of
331 if (goal_length == 0) {
334 p = argv[optind - 1];
335 if (p[0] == '-' && p[1] == ch && !p[2])
336 goal_length = get_positive(++p, "width must be nonzero", 1);
338 goal_length = get_positive(argv[optind] + 1,
339 "width must be nonzero", 1);
340 max_length = goal_length;
346 "usage: fmt [-cmps] [-d chars] [-l num] [-t num]\n"
347 " [-w width | -width | goal [maximum]] [file ...]\n"
348 "Options: -c center each line instead of formatting\n"
349 " -d <chars> double-space after <chars> at line end\n"
350 " -l <n> turn each <n> spaces at start of line into a tab\n"
351 " -m try to make sure mail header lines stay separate\n"
352 " -n format lines beginning with a dot\n"
353 " -p allow indented paragraphs\n"
354 " -s coalesce whitespace inside lines\n"
355 " -t <n> have tabs every <n> columns\n"
356 " -w <n> set maximum width to <n>\n"
357 " goal set target width to goal\n");
358 exit(ch == 'h' ? 0 : EX_USAGE);
363 /* [ goal [ maximum ] ] */
365 if (argc > 0 && goal_length == 0
366 && (goal_length = get_positive(*argv, "goal length must be positive", 0))
371 && (max_length = get_positive(*argv, "max length must be positive", 0))
375 if (max_length < goal_length)
376 errx(EX_USAGE, "max length must be >= goal length");
379 if (goal_length == 0)
382 max_length = goal_length + 10;
383 if (max_length >= SIZE_T_MAX / sizeof(wchar_t))
384 errx(EX_USAGE, "max length too large");
385 /* really needn't be longer */
386 output_buffer = XMALLOC((max_length + 1) * sizeof(wchar_t));
388 /* 2. Process files. */
392 process_named_file(*argv++);
394 process_stream(stdin, "standard input");
399 return n_errors ? EX_NOINPUT : 0;
403 /* Process a single file, given its name.
406 process_named_file(const char *name)
408 FILE *f = fopen(name, "r");
414 process_stream(f, name);
423 /* Types of mail header continuation lines:
426 hdr_ParagraphStart = -1,
432 /* Process a stream. This is where the real work happens,
433 * except that centering is handled separately.
436 process_stream(FILE *stream, const char *name)
438 size_t last_indent = SILLY; /* how many spaces in last indent? */
439 size_t para_line_number = 0; /* how many lines already read in this para? */
440 size_t first_indent = SILLY; /* indentation of line 0 of paragraph */
441 HdrType prev_header_type = hdr_ParagraphStart;
443 /* ^-- header_type of previous line; -1 at para start */
448 center_stream(stream, name);
451 while ((line = get_line(stream, &length)) != NULL) {
452 size_t np = indent_length(line, length);
455 HdrType header_type = hdr_NonHeader;
457 if (grok_mail_headers && prev_header_type != hdr_NonHeader) {
458 if (np == 0 && might_be_header(line))
459 header_type = hdr_Header;
460 else if (np > 0 && prev_header_type > hdr_NonHeader)
461 header_type = hdr_Continuation;
464 * We need a new paragraph if and only if: this line
465 * is blank, OR it's a troff request (and we don't
466 * format troff), OR it's a mail header, OR it's not
467 * a mail header AND the last line was one, OR the
468 * indentation has changed AND the line isn't a mail
469 * header continuation line AND this isn't the
470 * second line of an indented paragraph.
473 || (line[0] == '.' && !format_troff)
474 || header_type == hdr_Header
475 || (header_type == hdr_NonHeader && prev_header_type > hdr_NonHeader)
476 || (np != last_indent
477 && header_type != hdr_Continuation
478 && (!allow_indented_paragraphs || para_line_number != 1))) {
479 new_paragraph(output_in_paragraph ? last_indent : first_indent, np);
480 para_line_number = 0;
483 if (header_type == hdr_Header)
484 last_indent = 2; /* for cont. lines */
485 if (length == 0 || (line[0] == '.' && !format_troff)) {
489 wprintf(L"%.*ls\n", (int)length,
491 prev_header_type = hdr_ParagraphStart;
496 * If this is an indented paragraph other
497 * than a mail header continuation, set
500 if (np != last_indent &&
501 header_type != hdr_Continuation)
504 prev_header_type = header_type;
511 /* Find word end and count spaces after it */
512 size_t word_length = 0, space_length = 0;
514 while (n + word_length < length &&
515 line[n + word_length] != ' ')
517 space_length = word_length;
518 while (n + space_length < length &&
519 line[n + space_length] == ' ')
521 /* Send the word to the output machinery. */
522 output_word(first_indent, last_indent,
523 line + n, word_length,
524 space_length - word_length);
530 new_paragraph(output_in_paragraph ? last_indent : first_indent, 0);
531 if (ferror(stream)) {
537 /* How long is the indent on this line?
540 indent_length(const wchar_t *line, size_t length)
544 while (n < length && *line++ == ' ')
549 /* Might this line be a mail header?
550 * We deem a line to be a possible header if it matches the
551 * Perl regexp /^[A-Z][-A-Za-z0-9]*:\s/. This is *not* the same
552 * as in RFC whatever-number-it-is; we want to be gratuitously
553 * conservative to avoid mangling ordinary civilised text.
556 might_be_header(const wchar_t *line)
558 if (!iswupper(*line++))
560 while (*line && (iswalnum(*line) || *line == '-'))
562 return (*line == ':' && iswspace(line[1]));
565 /* Begin a new paragraph with an indent of |indent| spaces.
568 new_paragraph(size_t old_indent, size_t indent)
570 if (output_buffer_length) {
572 output_indent(old_indent);
573 wprintf(L"%.*ls\n", (int)output_buffer_length, output_buffer);
577 output_buffer_length = 0;
579 output_in_paragraph = 0;
582 /* Output spaces or tabs for leading indentation.
585 output_indent(size_t n_spaces)
587 if (output_tab_width) {
588 while (n_spaces >= output_tab_width) {
590 n_spaces -= output_tab_width;
593 while (n_spaces-- > 0)
597 /* Output a single word, or add it to the buffer.
598 * indent0 and indent1 are the indents to use on the first and subsequent
599 * lines of a paragraph. They'll often be the same, of course.
602 output_word(size_t indent0, size_t indent1, const wchar_t *word, size_t length, size_t spaces)
605 size_t indent = output_in_paragraph ? indent1 : indent0;
610 for (p = word, width = 0; p < &word[length]; p++)
611 width += (cwidth = wcwidth(*p)) > 0 ? cwidth : 1;
613 new_x = x + pending_spaces + width;
616 * If either |spaces==0| (at end of line) or |coalesce_spaces_P|
617 * (squashing internal whitespace), then add just one space; except
618 * that if the last character was a sentence-ender we actually add
621 if (coalesce_spaces_P || spaces == 0)
622 spaces = wcschr(sentence_enders, word[length - 1]) ? 2 : 1;
624 if (new_x <= goal_length) {
626 * After adding the word we still aren't at the goal length,
627 * so clearly we add it to the buffer rather than outputing
630 wmemset(output_buffer + output_buffer_length, L' ',
632 x0 += pending_spaces;
634 output_buffer_length += pending_spaces;
635 wmemcpy(output_buffer + output_buffer_length, word, length);
638 output_buffer_length += length;
639 pending_spaces = spaces;
642 * Adding the word takes us past the goal. Print the
643 * line-so-far, and the word too iff either (1) the lsf is
644 * empty or (2) that makes us nearer the goal but doesn't
645 * take us over the limit, or (3) the word on its own takes
646 * us over the limit. In case (3) we put a newline in
650 output_indent(indent);
651 wprintf(L"%.*ls", (int)output_buffer_length, output_buffer);
652 if (x0 == 0 || (new_x <= max_length &&
653 new_x - goal_length <= goal_length - x)) {
654 wprintf(L"%*ls", (int)pending_spaces, L"");
658 * If the word takes us over the limit on its own,
659 * just spit it out and don't bother buffering it.
661 if (indent + width > max_length) {
664 output_indent(indent);
666 wprintf(L"%.*ls", (int)length, word);
670 output_buffer_length = 0;
672 wmemcpy(output_buffer, word, length);
675 pending_spaces = spaces;
676 output_buffer_length = length;
680 output_in_paragraph = 1;
684 /* Process a stream, but just center its lines rather than trying to
685 * format them neatly.
688 center_stream(FILE *stream, const char *name)
695 while ((line = get_line(stream, &length)) != NULL) {
698 while (l > 0 && iswspace(*line)) {
703 for (p = line, width = 0; p < &line[length]; p++)
704 width += (cwidth = wcwidth(*p)) > 0 ? cwidth : 1;
706 while (l < goal_length) {
710 wprintf(L"%.*ls\n", (int)length, line);
712 if (ferror(stream)) {
718 /* Get a single line from a stream. Expand tabs, strip control
719 * characters and trailing whitespace, and handle backspaces.
720 * Return the address of the buffer containing the line, and
721 * put the length of the line in |lengthp|.
722 * This can cope with arbitrarily long lines, and with lines
723 * without terminating \n.
724 * If there are no characters left or an error happens, we
726 * Don't confuse |spaces_pending| here with the global
730 get_line(FILE *stream, size_t *lengthp)
732 static wchar_t *buf = NULL;
733 static size_t length = 0;
736 size_t spaces_pending = 0;
743 buf = XMALLOC(length * sizeof(wchar_t));
745 while ((ch = getwc(stream)) != '\n' && ch != WEOF) {
746 if (len + spaces_pending == 0 && ch == '.' && !format_troff)
750 else if (troff || iswprint(ch)) {
751 while (len + spaces_pending >= length) {
753 buf = xrealloc(buf, length * sizeof(wchar_t));
755 while (spaces_pending > 0) {
761 col += (cwidth = wcwidth(ch)) > 0 ? cwidth : 1;
762 } else if (ch == '\t')
763 spaces_pending += tab_width -
764 (col + spaces_pending) % tab_width;
765 else if (ch == '\b') {
773 return (len > 0 || ch != WEOF) ? buf : 0;
776 /* (Re)allocate some memory, exiting with an error if we can't.
779 xrealloc(void *ptr, size_t nbytes)
781 void *p = realloc(ptr, nbytes);
784 errx(EX_OSERR, "out of memory");