Annotation of src/usr.bin/fmt/fmt.c, Revision 1.31
1.31 ! deraadt 1: /* $OpenBSD: fmt.c,v 1.30 2013/11/26 13:18:55 deraadt Exp $ */
1.1 deraadt 2:
1.10 millert 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.
1.19 millert 33: * Unless the `-n' option is given, lines beginning with
34: * a . (dot) are not formatted.
1.10 millert 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
1.1 deraadt 133: * notice, this list of conditions and the following disclaimer.
1.10 millert 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
1.1 deraadt 169: */
170:
1.4 millert 171: #include <ctype.h>
1.18 millert 172: #include <err.h>
173: #include <locale.h>
1.1 deraadt 174: #include <stdio.h>
175: #include <stdlib.h>
176: #include <string.h>
1.18 millert 177: #include <sysexits.h>
178: #include <unistd.h>
1.10 millert 179:
180: /* Something that, we hope, will never be a genuine line length,
181: * indentation etc.
1.1 deraadt 182: */
1.10 millert 183: #define SILLY ((size_t)-1)
1.1 deraadt 184:
1.10 millert 185: /* I used to use |strtoul| for this, but (1) not all systems have it
186: * and (2) it's probably better to use |strtol| to detect negative
187: * numbers better.
188: * If |fussyp==0| then we don't complain about non-numbers
189: * (returning 0 instead), but we do complain about bad numbers.
190: */
1.18 millert 191: static size_t
1.21 tedu 192: get_positive(const char *s, const char *err_mess, int fussyP)
193: {
194: char *t;
195: long result = strtol(s, &t, 0);
196:
197: if (*t) {
198: if (fussyP)
199: goto Lose;
200: else
201: return 0;
202: }
203: if (result <= 0) {
204: Lose:
205: errx(EX_USAGE, "%s", err_mess);
206: }
207:
208: return (size_t) result;
1.1 deraadt 209: }
210:
1.10 millert 211: /* Global variables */
212:
1.21 tedu 213: static int centerP = 0; /* Try to center lines? */
214: static size_t goal_length = 0; /* Target length for output lines */
215: static size_t max_length = 0; /* Maximum length for output lines */
216: static int coalesce_spaces_P = 0; /* Coalesce multiple whitespace -> ' ' ? */
217: static int allow_indented_paragraphs = 0; /* Can first line have diff. ind.? */
218: static int tab_width = 8; /* Number of spaces per tab stop */
219: static size_t output_tab_width = 0; /* Ditto, when squashing leading spaces */
220: static const char *sentence_enders = ".?!"; /* Double-space after these */
221: static int grok_mail_headers = 0; /* treat embedded mail headers magically? */
222: static int format_troff = 0; /* Format troff? */
223:
1.28 schwarze 224: static int n_errors = 0; /* Number of failed files. */
1.21 tedu 225: static char *output_buffer = NULL; /* Output line will be built here */
226: static size_t x; /* Horizontal position in output line */
227: static size_t x0; /* Ditto, ignoring leading whitespace */
228: static size_t pending_spaces; /* Spaces to add before next word */
229: static int output_in_paragraph = 0; /* Any of current para written out yet? */
1.10 millert 230:
231: /* Prototypes */
232:
1.21 tedu 233: static void process_named_file(const char *);
234: static void process_stream(FILE *, const char *);
235: static size_t indent_length(const char *, size_t);
1.30 deraadt 236: static int might_be_header(const char *);
1.21 tedu 237: static void new_paragraph(size_t, size_t);
238: static void output_word(size_t, size_t, const char *, size_t, size_t);
239: static void output_indent(size_t);
240: static void center_stream(FILE *, const char *);
241: static char *get_line(FILE *, size_t *);
242: static void *xrealloc(void *, size_t);
243: void usage(void);
1.10 millert 244:
1.21 tedu 245: #define XMALLOC(x) xrealloc(0, x)
1.29 lum 246: #define ERRS(x) (x >= 127 ? 127 : ++x)
1.10 millert 247:
248: /* Here is perhaps the right place to mention that this code is
249: * all in top-down order. Hence, |main| comes first.
1.1 deraadt 250: */
1.4 millert 251: int
1.21 tedu 252: main(int argc, char *argv[])
253: {
254: int ch; /* used for |getopt| processing */
255:
256: (void)setlocale(LC_CTYPE, "");
257:
1.31 ! deraadt 258: if (tame("stdio rpath", NULL) == -1)
! 259: err(1, "tame");
! 260:
1.21 tedu 261: /* 1. Grok parameters. */
262: while ((ch = getopt(argc, argv, "0123456789cd:hl:mnpst:w:")) != -1) {
263: switch (ch) {
264: case 'c':
265: centerP = 1;
266: break;
267: case 'd':
268: sentence_enders = optarg;
269: break;
270: case 'l':
271: output_tab_width
272: = get_positive(optarg, "output tab width must be positive", 1);
273: break;
274: case 'm':
275: grok_mail_headers = 1;
276: break;
277: case 'n':
278: format_troff = 1;
279: break;
280: case 'p':
281: allow_indented_paragraphs = 1;
282: break;
283: case 's':
284: coalesce_spaces_P = 1;
285: break;
286: case 't':
287: tab_width = get_positive(optarg, "tab width must be positive", 1);
288: break;
289: case 'w':
290: goal_length = get_positive(optarg, "width must be positive", 1);
291: max_length = goal_length;
292: break;
293: case '0': case '1': case '2': case '3': case '4': case '5':
294: case '6': case '7': case '8': case '9':
295: /* XXX this is not a stylistically approved use of getopt() */
296: if (goal_length == 0) {
297: char *p;
298:
299: p = argv[optind - 1];
300: if (p[0] == '-' && p[1] == ch && !p[2])
301: goal_length = get_positive(++p, "width must be nonzero", 1);
302: else
303: goal_length = get_positive(argv[optind]+1,
304: "width must be nonzero", 1);
305: max_length = goal_length;
306: }
307: break;
308: case 'h':
309: default:
310: usage();
311: /* NOT REACHED */
312: }
313: }
314:
315: argc -= optind;
316: argv += optind;
317:
318: /* [ goal [ maximum ] ] */
319: if (argc > 0 && goal_length == 0 &&
320: (goal_length = get_positive(*argv,"goal length must be positive", 0)) != 0) {
321: --argc;
322: ++argv;
323: if (argc > 0 && (max_length = get_positive(*argv,"max length must be positive", 0)) != 0) {
324: --argc;
325: ++argv;
326: if (max_length < goal_length)
327: errx(EX_USAGE, "max length must be >= goal length");
328: }
329: }
330:
331: if (goal_length == 0)
332: goal_length = 65;
333: if (max_length == 0)
334: max_length = goal_length+10;
335: output_buffer = XMALLOC(max_length+1); /* really needn't be longer */
336:
337: /* 2. Process files. */
338:
339: if (argc > 0) {
340: while (argc-- > 0)
341: process_named_file(*argv++);
342: } else {
1.31 ! deraadt 343: if (tame("stdio", NULL) != 0)
! 344: err(1, "tame");
1.21 tedu 345: process_stream(stdin, "standard input");
346: }
1.10 millert 347:
1.21 tedu 348: /* We're done. */
1.29 lum 349: return n_errors;
1.10 millert 350:
351: }
352:
353: /* Process a single file, given its name.
354: */
355: static void
1.21 tedu 356: process_named_file(const char *name)
357: {
358: FILE *f;
359:
360: if ((f = fopen(name, "r")) == NULL) {
1.23 cloder 361: warn("%s", name);
1.29 lum 362: ERRS(n_errors);
1.21 tedu 363: } else {
364: process_stream(f, name);
365: fclose(f);
366: }
1.10 millert 367: }
368:
369: /* Types of mail header continuation lines:
370: */
371: typedef enum {
1.21 tedu 372: hdr_ParagraphStart = -1,
373: hdr_NonHeader = 0,
374: hdr_Header = 1,
375: hdr_Continuation = 2
1.10 millert 376: } HdrType;
377:
378: /* Process a stream. This is where the real work happens,
379: * except that centering is handled separately.
380: */
381: static void
1.21 tedu 382: process_stream(FILE *stream, const char *name)
383: {
384: size_t n;
385: size_t np;
386: size_t last_indent = SILLY; /* how many spaces in last indent? */
387: size_t para_line_number = 0; /* how many lines already read in this para? */
388: size_t first_indent = SILLY; /* indentation of line 0 of paragraph */
389: HdrType prev_header_type = hdr_ParagraphStart;
390: HdrType header_type;
391:
1.10 millert 392: /* ^-- header_type of previous line; -1 at para start */
1.30 deraadt 393: const char *line;
1.21 tedu 394: size_t length;
1.10 millert 395:
1.21 tedu 396: if (centerP) {
397: center_stream(stream, name);
398: return;
399: }
400:
401: while ((line = get_line(stream, &length)) != NULL) {
402: np = indent_length(line, length);
403: header_type = hdr_NonHeader;
404: if (grok_mail_headers && prev_header_type != hdr_NonHeader) {
405: if (np == 0 && might_be_header(line))
406: header_type = hdr_Header;
407: else if (np > 0 && prev_header_type>hdr_NonHeader)
408: header_type = hdr_Continuation;
409: }
410:
411: /* We need a new paragraph if and only if:
412: * this line is blank,
413: * OR it's a troff request,
414: * OR it's a mail header,
415: * OR it's not a mail header AND the last line was one,
416: * OR the indentation has changed
417: * AND the line isn't a mail header continuation line
418: * AND this isn't the second line of an indented paragraph.
419: */
420: if (length == 0 || (line[0] == '.' && !format_troff) ||
421: header_type == hdr_Header ||
422: (header_type == hdr_NonHeader && prev_header_type > hdr_NonHeader) ||
423: (np != last_indent && header_type != hdr_Continuation &&
424: (!allow_indented_paragraphs || para_line_number != 1)) ) {
425: new_paragraph(output_in_paragraph ? last_indent : first_indent, np);
426: para_line_number = 0;
427: first_indent = np;
428: last_indent = np;
429:
430: /* nroff compatibility */
431: if (length > 0 && line[0] == '.' && !format_troff) {
432: printf("%.*s\n", (int)length, line);
433: continue;
434: }
435: if (header_type == hdr_Header)
436: last_indent = 2; /* for cont. lines */
437: if (length == 0) {
438: putchar('\n');
439: prev_header_type = hdr_ParagraphStart;
440: continue;
441: } else {
442: /* If this is an indented paragraph other than a mail header
443: * continuation, set |last_indent|.
444: */
445: if (np != last_indent && header_type != hdr_Continuation)
446: last_indent = np;
447: }
448: prev_header_type = header_type;
449: }
450:
451: n = np;
452: while (n < length) {
453: /* Find word end and count spaces after it */
454: size_t word_length = 0, space_length = 0;
455: while (n+word_length < length && line[n+word_length] != ' ')
456: ++word_length;
457: space_length = word_length;
458: while (n+space_length < length && line[n+space_length] == ' ')
459: ++space_length;
460: /* Send the word to the output machinery. */
461: output_word(first_indent, last_indent,
462: line+n, word_length, space_length-word_length);
463: n += space_length;
464: }
465: ++para_line_number;
466: }
467:
468: new_paragraph(output_in_paragraph ? last_indent : first_indent, 0);
469: if (ferror(stream)) {
1.23 cloder 470: warn("%s", name);
1.29 lum 471: ERRS(n_errors);
1.21 tedu 472: }
1.10 millert 473: }
474:
475: /* How long is the indent on this line?
476: */
477: static size_t
1.21 tedu 478: indent_length(const char *line, size_t length)
479: {
480: size_t n = 0;
481:
482: while (n < length && *line++ == ' ')
483: ++n;
484: return n;
1.10 millert 485: }
486:
487: /* Might this line be a mail header?
488: * We deem a line to be a possible header if it matches the
489: * Perl regexp /^[A-Z][-A-Za-z0-9]*:\s/. This is *not* the same
490: * as in RFC whatever-number-it-is; we want to be gratuitously
491: * conservative to avoid mangling ordinary civilised text.
492: */
493: static int
1.30 deraadt 494: might_be_header(const char *line)
1.21 tedu 495: {
496:
1.30 deraadt 497: if (!isupper((unsigned char)*line++))
1.21 tedu 498: return 0;
1.30 deraadt 499: while (isalnum((unsigned char)*line) || *line == '-')
1.21 tedu 500: ++line;
1.30 deraadt 501: return (*line == ':' && isspace((unsigned char)line[1]));
1.10 millert 502: }
503:
504: /* Begin a new paragraph with an indent of |indent| spaces.
505: */
506: static void
1.21 tedu 507: new_paragraph(size_t old_indent, size_t indent)
508: {
509:
510: if (x0) {
511: if (old_indent > 0)
512: output_indent(old_indent);
513: fwrite(output_buffer, 1, x0, stdout);
514: putchar('\n');
515: }
516: x = indent;
517: x0 = 0;
518: pending_spaces = 0;
519: output_in_paragraph = 0;
1.10 millert 520: }
521:
522: /* Output spaces or tabs for leading indentation.
523: */
524: static void
1.21 tedu 525: output_indent(size_t n_spaces)
526: {
527:
528: if (output_tab_width) {
529: while (n_spaces >= output_tab_width) {
530: putchar('\t');
531: n_spaces -= output_tab_width;
532: }
533: }
534: while (n_spaces-- > 0)
535: putchar(' ');
1.10 millert 536: }
537:
538: /* Output a single word, or add it to the buffer.
539: * indent0 and indent1 are the indents to use on the first and subsequent
540: * lines of a paragraph. They'll often be the same, of course.
541: */
542: static void
1.21 tedu 543: output_word(size_t indent0, size_t indent1, const char *word, size_t length, size_t spaces)
544: {
545: size_t new_x = x + pending_spaces + length;
546: size_t indent = output_in_paragraph ? indent1 : indent0;
547:
548: /* If either |spaces==0| (at end of line) or |coalesce_spaces_P|
549: * (squashing internal whitespace), then add just one space;
550: * except that if the last character was a sentence-ender we
551: * actually add two spaces.
552: */
553: if (coalesce_spaces_P || spaces == 0)
554: spaces = strchr(sentence_enders, word[length-1]) ? 2 : 1;
555:
556: if (new_x <= goal_length) {
557: /* After adding the word we still aren't at the goal length,
558: * so clearly we add it to the buffer rather than outputing it.
559: */
560: memset(output_buffer+x0, ' ', pending_spaces);
561: x0 += pending_spaces;
562: x += pending_spaces;
563: memcpy(output_buffer+x0, word, length);
564: x0 += length;
565: x += length;
566: pending_spaces = spaces;
567: } else {
568: /* Adding the word takes us past the goal. Print the line-so-far,
569: * and the word too iff either (1) the lsf is empty or (2) that
570: * makes us nearer the goal but doesn't take us over the limit,
571: * or (3) the word on its own takes us over the limit.
572: * In case (3) we put a newline in between.
573: */
574: if (indent > 0)
575: output_indent(indent);
576: fwrite(output_buffer, 1, x0, stdout);
577: if (x0 == 0 || (new_x <= max_length && new_x-goal_length <= goal_length-x)) {
578: printf("%*s", (int)pending_spaces, "");
579: goto write_out_word;
580: } else {
581: /* If the word takes us over the limit on its own, just
582: * spit it out and don't bother buffering it.
583: */
584: if (indent+length > max_length) {
585: putchar('\n');
586: if (indent > 0)
587: output_indent(indent);
1.10 millert 588: write_out_word:
1.21 tedu 589: fwrite(word, 1, length, stdout);
590: x0 = 0;
591: x = indent1;
592: pending_spaces = 0;
593: } else {
594: memcpy(output_buffer, word, length);
595: x0 = length;
596: x = length+indent1;
597: pending_spaces = spaces;
598: }
599: }
600:
601: putchar('\n');
602: output_in_paragraph = 1;
603: }
1.10 millert 604: }
605:
606: /* Process a stream, but just center its lines rather than trying to
607: * format them neatly.
608: */
609: static void
1.21 tedu 610: center_stream(FILE *stream, const char *name)
611: {
612: char *line;
613: size_t length;
614: size_t l;
615:
616: while ((line = get_line(stream, &length)) != 0) {
617: l = length;
618: while (l > 0 && isspace(*line)) {
619: ++line;
620: --l;
621: }
622:
623: length = l;
624:
625: while (l < goal_length) {
626: putchar(' ');
627: l += 2;
628: }
629:
630: fwrite(line, 1, length, stdout);
631: putchar('\n');
632: }
633:
634: if (ferror(stream)) {
1.23 cloder 635: warn("%s", name);
1.29 lum 636: ERRS(n_errors);
1.21 tedu 637: }
1.10 millert 638: }
639:
640: /* Get a single line from a stream. Expand tabs, strip control
641: * characters and trailing whitespace, and handle backspaces.
642: * Return the address of the buffer containing the line, and
643: * put the length of the line in |lengthp|.
644: * This can cope with arbitrarily long lines, and with lines
645: * without terminating \n.
646: * If there are no characters left or an error happens, we
647: * return 0.
648: * Don't confuse |spaces_pending| here with the global
649: * |pending_spaces|.
650: */
651: static char *
1.21 tedu 652: get_line(FILE *stream, size_t *lengthp)
653: {
654: int ch;
655: int troff = 0;
656: static char *buf = NULL;
657: static size_t length = 0;
658: size_t len = 0;
659: size_t spaces_pending = 0;
660:
661: if (buf == NULL) {
662: length = 100;
663: buf = XMALLOC(length);
664: }
665:
666: while ((ch = getc(stream)) != '\n' && ch != EOF) {
667: if ((len + spaces_pending == 0) && (ch == '.' && !format_troff))
668: troff = 1;
669: if (ch == ' ') {
670: ++spaces_pending;
671: } else if (troff || !iscntrl(ch)) {
672: while (len + spaces_pending >= length) {
673: length *= 2;
674: buf = xrealloc(buf, length);
675: }
676:
677: while (spaces_pending > 0) {
678: --spaces_pending;
679: buf[len++] = ' ';
680: }
681: buf[len++] = ch;
682: } else if (ch == '\t') {
683: spaces_pending += tab_width - (len+spaces_pending)%tab_width;
684: } else if (ch == '\b') {
685: if (len)
686: --len;
687: }
688: }
689:
690: *lengthp = len;
691: return (len > 0 || ch != EOF) ? buf : 0;
1.10 millert 692: }
693:
694: /* (Re)allocate some memory, exiting with an error if we can't.
695: */
696: static void *
1.21 tedu 697: xrealloc(void *ptr, size_t nbytes)
698: {
699: void *p;
700:
701: p = realloc(ptr, nbytes);
702: if (p == NULL)
703: errx(EX_OSERR, "out of memory");
704: return p;
705: }
706:
707: void
708: usage(void)
709: {
1.22 mickey 710: extern char *__progname;
1.21 tedu 711:
712: fprintf(stderr,
1.25 jmc 713: "usage: %s [-cmnps] [-d chars] [-l number] [-t number]\n"
714: "\t[goal [maximum] | -width | -w width] [file ...]\n",
715: __progname);
1.22 mickey 716: exit (1);
1.1 deraadt 717: }