1 /* $OpenBSD: fmt.c,v 1.21 2004/04/01 23:14:19 tedu Exp $ */
2
3 /* Sensible version of fmt
4 *
5 * Syntax: fmt [ options ] [ goal [ max ] ] [ filename ... ]
6 *
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.
12 *
13 * 1. Tabs are expanded, assuming 8-space tab stops.
14 * If the `-t <n>' option is given, we assume <n>-space
15 * tab stops instead.
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
19 * includes \r.
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
50 * words left.
51 * Note that for a blank line this translates as "We emit
52 * a newline".
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.
67 *
68 * Multiple input files are formatted one at a time, so that a file
69 * never ends in the middle of a line.
70 *
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
75 * with old `fmt'.
76 *
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'.)
82 *
83 * Differences from old `fmt':
84 *
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
95 * behave right.)
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'
99 * does the reverse.
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
107 * old `fmt'.
108 *
109 * Bugs:
110 *
111 * None known. There probably are some, though.
112 *
113 * Portability:
114 *
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.
120 *
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.
124 */
125
126 /* Copyright (c) 1997 Gareth McCaughan. All rights reserved.
127 *
128 * Redistribution and use of this code, in source or binary forms,
129 * with or without modification, are permitted subject to the following
130 * conditions:
131 *
132 * - Redistribution of source code must retain the above copyright
133 * notice, this list of conditions and the following disclaimer.
134 *
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.
138 *
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.
146 */
147
148 /* RCS change log:
149 * Revision 1.5 1998/03/02 18:02:21 gjm11
150 * Minor changes for portability.
151 *
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.
158 *
159 * Revision 1.3 1997/09/30 16:24:47 gjm11
160 * Add copyright notice, rcsid string and log message.
161 *
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.
166 *
167 * Revision 1.1 1997/09/30 11:29:57 gjm11
168 * Initial revision
169 */
170
171 #ifndef lint
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 #include <err.h>
177 #include <limits.h>
178 #include <locale.h>
179 #include <stdio.h>
180 #include <stdlib.h>
181 #include <string.h>
182 #include <sysexits.h>
183 #include <unistd.h>
184 #include <wchar.h>
185 #include <wctype.h>
186
187 /* Something that, we hope, will never be a genuine line length,
188 * indentation etc.
189 */
190 #define SILLY ((size_t)-1)
191
192 /* I used to use |strtoul| for this, but (1) not all systems have it
193 * and (2) it's probably better to use |strtol| to detect negative
194 * numbers better.
195 * If |fussyp==0| then we don't complain about non-numbers
196 * (returning 0 instead), but we do complain about bad numbers.
197 */
198 static size_t
get_positive(const char * s,const char * err_mess,int fussyP)199 get_positive(const char *s, const char *err_mess, int fussyP)
200 {
201 char *t;
202 long result = strtol(s, &t, 0);
203
204 if (*t) {
205 if (fussyP)
206 goto Lose;
207 else
208 return 0;
209 }
210 if (result <= 0) {
211 Lose: errx(EX_USAGE, "%s", err_mess);
212 }
213 return (size_t)result;
214 }
215
216 static size_t
get_nonnegative(const char * s,const char * err_mess,int fussyP)217 get_nonnegative(const char *s, const char *err_mess, int fussyP)
218 {
219 char *t;
220 long result = strtol(s, &t, 0);
221
222 if (*t) {
223 if (fussyP)
224 goto Lose;
225 else
226 return 0;
227 }
228 if (result < 0) {
229 Lose: errx(EX_USAGE, "%s", err_mess);
230 }
231 return (size_t)result;
232 }
233
234 /* Global variables */
235
236 static int centerP = 0; /* Try to center lines? */
237 static size_t goal_length = 0; /* Target length for output lines */
238 static size_t max_length = 0; /* Maximum length for output lines */
239 static int coalesce_spaces_P = 0; /* Coalesce multiple whitespace -> ' ' ? */
240 static int allow_indented_paragraphs = 0; /* Can first line have diff. ind.? */
241 static int tab_width = 8; /* Number of spaces per tab stop */
242 static size_t output_tab_width = 8; /* Ditto, when squashing leading spaces */
243 static const wchar_t *sentence_enders = L".?!"; /* Double-space after these */
244 static int grok_mail_headers = 0; /* treat embedded mail headers magically? */
245 static int format_troff = 0; /* Format troff? */
246
247 static int n_errors = 0; /* Number of failed files. Return on exit. */
248 static wchar_t *output_buffer = NULL; /* Output line will be built here */
249 static size_t x; /* Horizontal position in output line */
250 static size_t x0; /* Ditto, ignoring leading whitespace */
251 static size_t output_buffer_length = 0;
252 static size_t pending_spaces; /* Spaces to add before next word */
253 static int output_in_paragraph = 0; /* Any of current para written out yet? */
254
255 /* Prototypes */
256
257 static void process_named_file(const char *);
258 static void process_stream(FILE *, const char *);
259 static size_t indent_length(const wchar_t *, size_t);
260 static int might_be_header(const wchar_t *);
261 static void new_paragraph(size_t, size_t);
262 static void output_word(size_t, size_t, const wchar_t *, size_t, size_t);
263 static void output_indent(size_t);
264 static void center_stream(FILE *, const char *);
265 static wchar_t *get_line(FILE *, size_t *);
266 static void *xrealloc(void *, size_t);
267
268 #define XMALLOC(x) xrealloc(0,x)
269
270 /* Here is perhaps the right place to mention that this code is
271 * all in top-down order. Hence, |main| comes first.
272 */
273 int
main(int argc,char * argv[])274 main(int argc, char *argv[])
275 {
276 int ch; /* used for |getopt| processing */
277 wchar_t *tmp;
278 size_t len;
279 const char *src;
280
281 (void)setlocale(LC_CTYPE, "");
282
283 /* 1. Grok parameters. */
284
285 while ((ch = getopt(argc, argv, "0123456789cd:hl:mnpst:w:")) != -1)
286 switch (ch) {
287 case 'c':
288 centerP = 1;
289 format_troff = 1;
290 continue;
291 case 'd':
292 src = optarg;
293 len = mbsrtowcs(NULL, &src, 0, NULL);
294 if (len == (size_t)-1)
295 err(EX_USAGE, "bad sentence-ending character set");
296 tmp = XMALLOC((len + 1) * sizeof(wchar_t));
297 mbsrtowcs(tmp, &src, len + 1, NULL);
298 sentence_enders = tmp;
299 continue;
300 case 'l':
301 output_tab_width
302 = get_nonnegative(optarg, "output tab width must be non-negative", 1);
303 continue;
304 case 'm':
305 grok_mail_headers = 1;
306 continue;
307 case 'n':
308 format_troff = 1;
309 continue;
310 case 'p':
311 allow_indented_paragraphs = 1;
312 continue;
313 case 's':
314 coalesce_spaces_P = 1;
315 continue;
316 case 't':
317 tab_width = get_positive(optarg, "tab width must be positive", 1);
318 continue;
319 case 'w':
320 goal_length = get_positive(optarg, "width must be positive", 1);
321 max_length = goal_length;
322 continue;
323 case '0': case '1': case '2': case '3': case '4': case '5':
324 case '6': case '7': case '8': case '9':
325 /*
326 * XXX this is not a stylistically approved use of
327 * getopt()
328 */
329 if (goal_length == 0) {
330 char *p;
331
332 p = argv[optind - 1];
333 if (p[0] == '-' && p[1] == ch && !p[2])
334 goal_length = get_positive(++p, "width must be nonzero", 1);
335 else
336 goal_length = get_positive(argv[optind] + 1,
337 "width must be nonzero", 1);
338 max_length = goal_length;
339 }
340 continue;
341 case 'h':
342 default:
343 fprintf(stderr,
344 "usage: fmt [-cmps] [-d chars] [-l num] [-t num]\n"
345 " [-w width | -width | goal [maximum]] [file ...]\n"
346 "Options: -c center each line instead of formatting\n"
347 " -d <chars> double-space after <chars> at line end\n"
348 " -l <n> turn each <n> spaces at start of line into a tab\n"
349 " -m try to make sure mail header lines stay separate\n"
350 " -n format lines beginning with a dot\n"
351 " -p allow indented paragraphs\n"
352 " -s coalesce whitespace inside lines\n"
353 " -t <n> have tabs every <n> columns\n"
354 " -w <n> set maximum width to <n>\n"
355 " goal set target width to goal\n");
356 exit(ch == 'h' ? 0 : EX_USAGE);
357 }
358 argc -= optind;
359 argv += optind;
360
361 /* [ goal [ maximum ] ] */
362
363 if (argc > 0 && goal_length == 0
364 && (goal_length = get_positive(*argv, "goal length must be positive", 0))
365 != 0) {
366 --argc;
367 ++argv;
368 if (argc > 0
369 && (max_length = get_positive(*argv, "max length must be positive", 0))
370 != 0) {
371 --argc;
372 ++argv;
373 if (max_length < goal_length)
374 errx(EX_USAGE, "max length must be >= goal length");
375 }
376 }
377 if (goal_length == 0)
378 goal_length = 65;
379 if (max_length == 0)
380 max_length = goal_length + 10;
381 if (max_length >= SIZE_T_MAX / sizeof(wchar_t))
382 errx(EX_USAGE, "max length too large");
383 /* really needn't be longer */
384 output_buffer = XMALLOC((max_length + 1) * sizeof(wchar_t));
385
386 /* 2. Process files. */
387
388 if (argc > 0) {
389 while (argc-- > 0)
390 process_named_file(*argv++);
391 } else {
392 process_stream(stdin, "standard input");
393 }
394
395 /* We're done. */
396
397 return n_errors ? EX_NOINPUT : 0;
398
399 }
400
401 /* Process a single file, given its name.
402 */
403 static void
process_named_file(const char * name)404 process_named_file(const char *name)
405 {
406 FILE *f = fopen(name, "r");
407
408 if (!f) {
409 warn("%s", name);
410 ++n_errors;
411 } else {
412 process_stream(f, name);
413 if (ferror(f)) {
414 warn("%s", name);
415 ++n_errors;
416 }
417 fclose(f);
418 }
419 }
420
421 /* Types of mail header continuation lines:
422 */
423 typedef enum {
424 hdr_ParagraphStart = -1,
425 hdr_NonHeader = 0,
426 hdr_Header = 1,
427 hdr_Continuation = 2
428 } HdrType;
429
430 /* Process a stream. This is where the real work happens,
431 * except that centering is handled separately.
432 */
433 static void
process_stream(FILE * stream,const char * name)434 process_stream(FILE *stream, const char *name)
435 {
436 size_t last_indent = SILLY; /* how many spaces in last indent? */
437 size_t para_line_number = 0; /* how many lines already read in this para? */
438 size_t first_indent = SILLY; /* indentation of line 0 of paragraph */
439 HdrType prev_header_type = hdr_ParagraphStart;
440
441 /* ^-- header_type of previous line; -1 at para start */
442 wchar_t *line;
443 size_t length;
444
445 if (centerP) {
446 center_stream(stream, name);
447 return;
448 }
449 while ((line = get_line(stream, &length)) != NULL) {
450 size_t np = indent_length(line, length);
451
452 {
453 HdrType header_type = hdr_NonHeader;
454
455 if (grok_mail_headers && prev_header_type != hdr_NonHeader) {
456 if (np == 0 && might_be_header(line))
457 header_type = hdr_Header;
458 else if (np > 0 && prev_header_type > hdr_NonHeader)
459 header_type = hdr_Continuation;
460 }
461 /*
462 * We need a new paragraph if and only if: this line
463 * is blank, OR it's a troff request (and we don't
464 * format troff), OR it's a mail header, OR it's not
465 * a mail header AND the last line was one, OR the
466 * indentation has changed AND the line isn't a mail
467 * header continuation line AND this isn't the
468 * second line of an indented paragraph.
469 */
470 if (length == 0
471 || (line[0] == '.' && !format_troff)
472 || header_type == hdr_Header
473 || (header_type == hdr_NonHeader && prev_header_type > hdr_NonHeader)
474 || (np != last_indent
475 && header_type != hdr_Continuation
476 && (!allow_indented_paragraphs || para_line_number != 1))) {
477 new_paragraph(output_in_paragraph ? last_indent : first_indent, np);
478 para_line_number = 0;
479 first_indent = np;
480 last_indent = np;
481 if (header_type == hdr_Header)
482 last_indent = 2; /* for cont. lines */
483 if (length == 0 || (line[0] == '.' && !format_troff)) {
484 if (length == 0)
485 putwchar('\n');
486 else
487 wprintf(L"%.*ls\n", (int)length,
488 line);
489 prev_header_type = hdr_ParagraphStart;
490 continue;
491 }
492 } else {
493 /*
494 * If this is an indented paragraph other
495 * than a mail header continuation, set
496 * |last_indent|.
497 */
498 if (np != last_indent &&
499 header_type != hdr_Continuation)
500 last_indent = np;
501 }
502 prev_header_type = header_type;
503 }
504
505 {
506 size_t n = np;
507
508 while (n < length) {
509 /* Find word end and count spaces after it */
510 size_t word_length = 0, space_length = 0;
511
512 while (n + word_length < length &&
513 line[n + word_length] != ' ')
514 ++word_length;
515 space_length = word_length;
516 while (n + space_length < length &&
517 line[n + space_length] == ' ')
518 ++space_length;
519 /* Send the word to the output machinery. */
520 output_word(first_indent, last_indent,
521 line + n, word_length,
522 space_length - word_length);
523 n += space_length;
524 }
525 }
526 ++para_line_number;
527 }
528 new_paragraph(output_in_paragraph ? last_indent : first_indent, 0);
529 if (ferror(stream)) {
530 warn("%s", name);
531 ++n_errors;
532 }
533 }
534
535 /* How long is the indent on this line?
536 */
537 static size_t
indent_length(const wchar_t * line,size_t length)538 indent_length(const wchar_t *line, size_t length)
539 {
540 size_t n = 0;
541
542 while (n < length && *line++ == ' ')
543 ++n;
544 return n;
545 }
546
547 /* Might this line be a mail header?
548 * We deem a line to be a possible header if it matches the
549 * Perl regexp /^[A-Z][-A-Za-z0-9]*:\s/. This is *not* the same
550 * as in RFC whatever-number-it-is; we want to be gratuitously
551 * conservative to avoid mangling ordinary civilised text.
552 */
553 static int
might_be_header(const wchar_t * line)554 might_be_header(const wchar_t *line)
555 {
556 if (!iswupper(*line++))
557 return 0;
558 while (*line && (iswalnum(*line) || *line == '-'))
559 ++line;
560 return (*line == ':' && iswspace(line[1]));
561 }
562
563 /* Begin a new paragraph with an indent of |indent| spaces.
564 */
565 static void
new_paragraph(size_t old_indent,size_t indent)566 new_paragraph(size_t old_indent, size_t indent)
567 {
568 if (output_buffer_length) {
569 if (old_indent > 0)
570 output_indent(old_indent);
571 wprintf(L"%.*ls\n", (int)output_buffer_length, output_buffer);
572 }
573 x = indent;
574 x0 = 0;
575 output_buffer_length = 0;
576 pending_spaces = 0;
577 output_in_paragraph = 0;
578 }
579
580 /* Output spaces or tabs for leading indentation.
581 */
582 static void
output_indent(size_t n_spaces)583 output_indent(size_t n_spaces)
584 {
585 if (output_tab_width) {
586 while (n_spaces >= output_tab_width) {
587 putwchar('\t');
588 n_spaces -= output_tab_width;
589 }
590 }
591 while (n_spaces-- > 0)
592 putwchar(' ');
593 }
594
595 /* Output a single word, or add it to the buffer.
596 * indent0 and indent1 are the indents to use on the first and subsequent
597 * lines of a paragraph. They'll often be the same, of course.
598 */
599 static void
output_word(size_t indent0,size_t indent1,const wchar_t * word,size_t length,size_t spaces)600 output_word(size_t indent0, size_t indent1, const wchar_t *word, size_t length, size_t spaces)
601 {
602 size_t new_x;
603 size_t indent = output_in_paragraph ? indent1 : indent0;
604 size_t width;
605 const wchar_t *p;
606 int cwidth;
607
608 for (p = word, width = 0; p < &word[length]; p++)
609 width += (cwidth = wcwidth(*p)) > 0 ? cwidth : 1;
610
611 new_x = x + pending_spaces + width;
612
613 /*
614 * If either |spaces==0| (at end of line) or |coalesce_spaces_P|
615 * (squashing internal whitespace), then add just one space; except
616 * that if the last character was a sentence-ender we actually add
617 * two spaces.
618 */
619 if (coalesce_spaces_P || spaces == 0)
620 spaces = wcschr(sentence_enders, word[length - 1]) ? 2 : 1;
621
622 if (new_x <= goal_length) {
623 /*
624 * After adding the word we still aren't at the goal length,
625 * so clearly we add it to the buffer rather than outputting
626 * it.
627 */
628 wmemset(output_buffer + output_buffer_length, L' ',
629 pending_spaces);
630 x0 += pending_spaces;
631 x += pending_spaces;
632 output_buffer_length += pending_spaces;
633 wmemcpy(output_buffer + output_buffer_length, word, length);
634 x0 += width;
635 x += width;
636 output_buffer_length += length;
637 pending_spaces = spaces;
638 } else {
639 /*
640 * Adding the word takes us past the goal. Print the
641 * line-so-far, and the word too iff either (1) the lsf is
642 * empty or (2) that makes us nearer the goal but doesn't
643 * take us over the limit, or (3) the word on its own takes
644 * us over the limit. In case (3) we put a newline in
645 * between.
646 */
647 if (indent > 0)
648 output_indent(indent);
649 wprintf(L"%.*ls", (int)output_buffer_length, output_buffer);
650 if (x0 == 0 || (new_x <= max_length &&
651 new_x - goal_length <= goal_length - x)) {
652 wprintf(L"%*ls", (int)pending_spaces, L"");
653 goto write_out_word;
654 } else {
655 /*
656 * If the word takes us over the limit on its own,
657 * just spit it out and don't bother buffering it.
658 */
659 if (indent + width > max_length) {
660 putwchar('\n');
661 if (indent > 0)
662 output_indent(indent);
663 write_out_word:
664 wprintf(L"%.*ls", (int)length, word);
665 x0 = 0;
666 x = indent1;
667 pending_spaces = 0;
668 output_buffer_length = 0;
669 } else {
670 wmemcpy(output_buffer, word, length);
671 x0 = width;
672 x = width + indent1;
673 pending_spaces = spaces;
674 output_buffer_length = length;
675 }
676 }
677 putwchar('\n');
678 output_in_paragraph = 1;
679 }
680 }
681
682 /* Process a stream, but just center its lines rather than trying to
683 * format them neatly.
684 */
685 static void
center_stream(FILE * stream,const char * name)686 center_stream(FILE *stream, const char *name)
687 {
688 wchar_t *line, *p;
689 size_t length;
690 size_t width;
691 int cwidth;
692
693 while ((line = get_line(stream, &length)) != NULL) {
694 size_t l = length;
695
696 while (l > 0 && iswspace(*line)) {
697 ++line;
698 --l;
699 }
700 length = l;
701 for (p = line, width = 0; p < &line[length]; p++)
702 width += (cwidth = wcwidth(*p)) > 0 ? cwidth : 1;
703 l = width;
704 while (l < goal_length) {
705 putwchar(' ');
706 l += 2;
707 }
708 wprintf(L"%.*ls\n", (int)length, line);
709 }
710 if (ferror(stream)) {
711 warn("%s", name);
712 ++n_errors;
713 }
714 }
715
716 /* Get a single line from a stream. Expand tabs, strip control
717 * characters and trailing whitespace, and handle backspaces.
718 * Return the address of the buffer containing the line, and
719 * put the length of the line in |lengthp|.
720 * This can cope with arbitrarily long lines, and with lines
721 * without terminating \n.
722 * If there are no characters left or an error happens, we
723 * return 0.
724 * Don't confuse |spaces_pending| here with the global
725 * |pending_spaces|.
726 */
727 static wchar_t *
get_line(FILE * stream,size_t * lengthp)728 get_line(FILE *stream, size_t *lengthp)
729 {
730 static wchar_t *buf = NULL;
731 static size_t length = 0;
732 size_t len = 0;
733 wint_t ch;
734 size_t spaces_pending = 0;
735 int troff = 0;
736 size_t col = 0;
737 int cwidth;
738
739 if (buf == NULL) {
740 length = 100;
741 buf = XMALLOC(length * sizeof(wchar_t));
742 }
743 while ((ch = getwc(stream)) != '\n' && ch != WEOF) {
744 if (len + spaces_pending == 0 && ch == '.' && !format_troff)
745 troff = 1;
746 if (ch == ' ')
747 ++spaces_pending;
748 else if (troff || iswprint(ch)) {
749 while (len + spaces_pending >= length) {
750 length *= 2;
751 buf = xrealloc(buf, length * sizeof(wchar_t));
752 }
753 while (spaces_pending > 0) {
754 --spaces_pending;
755 buf[len++] = ' ';
756 col++;
757 }
758 buf[len++] = ch;
759 col += (cwidth = wcwidth(ch)) > 0 ? cwidth : 1;
760 } else if (ch == '\t')
761 spaces_pending += tab_width -
762 (col + spaces_pending) % tab_width;
763 else if (ch == '\b') {
764 if (len)
765 --len;
766 if (col)
767 --col;
768 }
769 }
770 *lengthp = len;
771 return (len > 0 || ch != WEOF) ? buf : 0;
772 }
773
774 /* (Re)allocate some memory, exiting with an error if we can't.
775 */
776 static void *
xrealloc(void * ptr,size_t nbytes)777 xrealloc(void *ptr, size_t nbytes)
778 {
779 void *p = realloc(ptr, nbytes);
780
781 if (p == NULL)
782 errx(EX_OSERR, "out of memory");
783 return p;
784 }
785