1 /* GNU fmt -- simple text formatter.
2 Copyright (C) 94, 95, 96, 1997, 1998 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18 /* Written by Ross Paterson <rap@doc.ic.ac.uk>. */
22 #include <sys/types.h>
25 /* Redefine. Otherwise, systems (Unicos for one) with headers that define
26 it to be a type get syntax errors for the variable declaration below. */
27 #define word unused_word_type
33 /* The following parameters represent the program's idea of what is
34 "best". Adjust to taste, subject to the caveats given. */
36 /* Default longest permitted line length (max_width). */
39 /* Prefer lines to be LEEWAY % shorter than the maximum width, giving
40 room for optimization. */
43 /* The default secondary indent of tagged paragraph used for unindented
44 one-line paragraphs not preceded by any multi-line paragraphs. */
47 /* Costs and bonuses are expressed as the equivalent departure from the
48 optimal line length, multiplied by 10. e.g. assigning something a
49 cost of 50 means that it is as bad as a line 5 characters too short
50 or too long. The definition of SHORT_COST(n) should not be changed.
51 However, EQUIV(n) may need tuning. */
55 #define MAXCOST (~(((unsigned long) 1) << (8 * sizeof (COST) -1)))
57 #define SQR(n) ((n) * (n))
58 #define EQUIV(n) SQR ((COST) (n))
60 /* Cost of a filled line n chars longer or shorter than best_width. */
61 #define SHORT_COST(n) EQUIV ((n) * 10)
63 /* Cost of the difference between adjacent filled lines. */
64 #define RAGGED_COST(n) (SHORT_COST (n) / 2)
66 /* Basic cost per line. */
67 #define LINE_COST EQUIV (70)
69 /* Cost of breaking a line after the first word of a sentence, where
70 the length of the word is N. */
71 #define WIDOW_COST(n) (EQUIV (200) / ((n) + 2))
73 /* Cost of breaking a line before the last word of a sentence, where
74 the length of the word is N. */
75 #define ORPHAN_COST(n) (EQUIV (150) / ((n) + 2))
77 /* Bonus for breaking a line at the end of a sentence. */
78 #define SENTENCE_BONUS EQUIV (50)
80 /* Cost of breaking a line after a period not marking end of a sentence.
81 With the definition of sentence we are using (borrowed from emacs, see
82 get_line()) such a break would then look like a sentence break. Hence
83 we assign a very high cost -- it should be avoided unless things are
85 #define NOBREAK_COST EQUIV (600)
87 /* Bonus for breaking a line before open parenthesis. */
88 #define PAREN_BONUS EQUIV (40)
90 /* Bonus for breaking a line after other punctuation. */
91 #define PUNCT_BONUS EQUIV(40)
93 /* Credit for breaking a long paragraph one line later. */
94 #define LINE_CREDIT EQUIV(3)
96 /* Size of paragraph buffer, in words and characters. Longer paragraphs
97 are handled neatly (cf. flush_paragraph()), so there's little to gain
98 by making these larger. */
100 #define MAXCHARS 5000
102 /* Extra ctype(3)-style macros. */
104 #define isopen(c) (strchr ("([`'\"", c) != NULL)
105 #define isclose(c) (strchr (")]'\"", c) != NULL)
106 #define isperiod(c) (strchr (".?!", c) != NULL)
108 /* Size of a tab stop, for expansion on input and re-introduction on
112 /* Miscellaneous definitions. */
114 typedef unsigned int bool;
120 /* Word descriptor structure. */
122 typedef struct Word WORD;
127 /* Static attributes determined during input. */
129 const char *text; /* the text of the word */
130 short length; /* length of this word */
131 short space; /* the size of the following space */
132 bool paren:1; /* starts with open paren */
133 bool period:1; /* ends in [.?!])* */
134 bool punct:1; /* ends in punctuation */
135 bool final:1; /* end of sentence */
137 /* The remaining fields are computed during the optimization. */
139 short line_length; /* length of the best line starting here */
140 COST best_cost; /* cost of best paragraph starting here */
141 WORD *next_break; /* break which achieves best_cost */
144 /* Forward declarations. */
146 static void set_prefix PARAMS ((char *p));
147 static void fmt PARAMS ((FILE *f));
148 static bool get_paragraph PARAMS ((FILE *f));
149 static int get_line PARAMS ((FILE *f, int c));
150 static int get_prefix PARAMS ((FILE *f));
151 static int get_space PARAMS ((FILE *f, int c));
152 static int copy_rest PARAMS ((FILE *f, int c));
153 static bool same_para PARAMS ((int c));
154 static void flush_paragraph PARAMS ((void));
155 static void fmt_paragraph PARAMS ((void));
156 static void check_punctuation PARAMS ((WORD *w));
157 static COST base_cost PARAMS ((WORD *this));
158 static COST line_cost PARAMS ((WORD *next, int len));
159 static void put_paragraph PARAMS ((WORD *finish));
160 static void put_line PARAMS ((WORD *w, int indent));
161 static void put_word PARAMS ((WORD *w));
162 static void put_space PARAMS ((int space));
164 /* The name this program was run with. */
165 const char *program_name;
167 /* If nonzero, display usage information and exit. */
168 static int show_help = 0;
170 /* If nonzero, print the version on standard output and exit. */
171 static int show_version = 0;
175 /* If TRUE, first 2 lines may have different indent (default FALSE). */
178 /* If TRUE, first 2 lines _must_ have different indent (default FALSE). */
181 /* If TRUE, each line is a paragraph on its own (default FALSE). */
184 /* If TRUE, don't preserve inter-word spacing (default FALSE). */
187 /* Prefix minus leading and trailing spaces (default ""). */
188 static const char *prefix;
190 /* User-supplied maximum line width (default WIDTH). The only output
192 longer than this will each comprise a single word. */
193 static int max_width;
195 /* Values derived from the option values. */
197 /* The length of prefix minus leading space. */
198 static int prefix_full_length;
200 /* The length of the leading space trimmed from the prefix. */
201 static int prefix_lead_space;
203 /* The length of prefix minus leading and trailing space. */
204 static int prefix_length;
206 /* The preferred width of text lines, set to LEEWAY % less than max_width. */
207 static int best_width;
209 /* Dynamic variables. */
211 /* Start column of the character most recently read from the input file. */
212 static int in_column;
214 /* Start column of the next character to be written to stdout. */
215 static int out_column;
217 /* Space for the paragraph text -- longer paragraphs are handled neatly
218 (cf. flush_paragraph()). */
219 static char parabuf[MAXCHARS];
221 /* A pointer into parabuf, indicating the first unused character position. */
224 /* The words of a paragraph -- longer paragraphs are handled neatly
225 (cf. flush_paragraph()). */
226 static WORD word[MAXWORDS];
228 /* A pointer into the above word array, indicating the first position
229 after the last complete word. Sometimes it will point at an incomplete
231 static WORD *word_limit;
233 /* If TRUE, current input file contains tab characters, and so tabs can be
234 used for white space on output. */
237 /* Space before trimmed prefix on each line of the current paragraph. */
238 static int prefix_indent;
240 /* Indentation of the first line of the current paragraph. */
241 static int first_indent;
243 /* Indentation of other lines of the current paragraph */
244 static int other_indent;
246 /* To detect the end of a paragraph, we need to look ahead to the first
247 non-blank character after the prefix on the next line, or the first
248 character on the following line that failed to match the prefix.
249 We can reconstruct the lookahead from that character (next_char), its
250 position on the line (in_column) and the amount of space before the
251 prefix (next_prefix_indent). See get_paragraph() and copy_rest(). */
253 /* The last character read from the input file. */
254 static int next_char;
256 /* The space before the trimmed prefix (or part of it) on the next line
257 after the current paragraph. */
258 static int next_prefix_indent;
260 /* If nonzero, the length of the last line output in the current
261 paragraph, used to charge for raggedness at the split point for long
262 paragraphs chosen by fmt_paragraph(). */
263 static int last_line_length;
269 fprintf (stderr, _("Try `%s --help' for more information.\n"),
273 printf (_("Usage: %s [-DIGITS] [OPTION]... [FILE]...\n"), program_name);
275 Reformat each paragraph in the FILE(s), writing to standard output.\n\
276 If no FILE or if FILE is `-', read standard input.\n\
278 Mandatory arguments to long options are mandatory for short options too.\n\
279 -c, --crown-margin preserve indentation of first two lines\n\
280 -p, --prefix=STRING combine only lines having STRING as prefix\n\
281 -s, --split-only split long lines, but do not refill\n\
282 -t, --tagged-paragraph indentation of first line different from second\n\
283 -u, --uniform-spacing one space between words, two after sentences\n\
284 -w, --width=NUMBER maximum line width (default of 75 columns)\n\
285 --help display this help and exit\n\
286 --version output version information and exit\n\
288 In -wNUMBER, the letter `w' may be omitted.\n"),
290 puts (_("\nReport bugs to <textutils-bugs@gnu.org>."));
292 exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
295 /* Decode options and launch execution. */
297 static const struct option long_options[] =
299 {"crown-margin", no_argument, NULL, 'c'},
300 {"help", no_argument, &show_help, 1},
301 {"prefix", required_argument, NULL, 'p'},
302 {"split-only", no_argument, NULL, 's'},
303 {"tagged-paragraph", no_argument, NULL, 't'},
304 {"uniform-spacing", no_argument, NULL, 'u'},
305 {"version", no_argument, &show_version, 1},
306 {"width", required_argument, NULL, 'w'},
311 main (register int argc, register char **argv)
315 program_name = argv[0];
316 setlocale (LC_ALL, "");
317 bindtextdomain (PACKAGE, LOCALEDIR);
318 textdomain (PACKAGE);
320 crown = tagged = split = uniform = FALSE;
323 prefix_length = prefix_lead_space = prefix_full_length = 0;
325 if (argc > 1 && argv[1][0] == '-' && ISDIGIT (argv[1][1]))
328 /* Old option syntax; a dash followed by one or more digits.
329 Move past the number. */
330 for (++argv[1]; ISDIGIT (*argv[1]); ++argv[1])
332 /* FIXME: use strtol to detect overflow. */
333 max_width = max_width * 10 + *argv[1] - '0';
335 /* Make the options we just parsed invisible to getopt. */
341 while ((optchar = getopt_long (argc, argv, "0123456789cstuw:p:",
371 if (xstrtol (optarg, NULL, 10, &tmp_long, "") != LONGINT_OK
372 || tmp_long <= 0 || tmp_long > INT_MAX)
373 error (EXIT_FAILURE, 0, _("invalid line number increment: `%s'"),
375 max_width = (int) tmp_long;
387 printf ("fmt (%s) %s\n", GNU_PACKAGE, VERSION);
394 best_width = max_width * (2 * (100 - LEEWAY) + 1) / 200;
400 for (; optind < argc; optind++)
402 char *file = argv[optind];
403 if (STREQ (file, "-"))
408 in_stream = fopen (file, "r");
409 if (in_stream != NULL)
412 if (fclose (in_stream) == EOF)
413 error (EXIT_FAILURE, errno, file);
416 error (0, errno, file);
421 if (ferror (stdout) || fclose (stdout) == EOF)
422 error (EXIT_FAILURE, errno, _("write error"));
427 /* Trim space from the front and back of the string P, yielding the prefix,
428 and record the lengths of the prefix and the space trimmed. */
431 set_prefix (register char *p)
435 prefix_lead_space = 0;
442 prefix_full_length = strlen (p);
443 s = p + prefix_full_length;
444 while (s > p && s[-1] == ' ')
447 prefix_length = s - p;
450 /* read file F and send formatted output to stdout. */
457 next_char = get_prefix (f);
458 while (get_paragraph (f))
461 put_paragraph (word_limit);
465 /* Read a paragraph from input file F. A paragraph consists of a
466 maximal number of non-blank (excluding any prefix) lines subject to:
467 * In split mode, a paragraph is a single non-blank line.
468 * In crown mode, the second and subsequent lines must have the
469 same indentation, but possibly different from the indent of the
471 * Tagged mode is similar, but the first and second lines must have
472 different indentations.
473 * Otherwise, all lines of a paragraph must have the same indent.
474 If a prefix is in effect, it must be present at the same indent for
475 each line in the paragraph.
477 Return FALSE if end-of-file was encountered before the start of a
478 paragraph, else TRUE. */
481 get_paragraph (FILE *f)
485 last_line_length = 0;
488 /* Scan (and copy) blank lines, and lines not introduced by the prefix. */
490 while (c == '\n' || c == EOF
491 || next_prefix_indent < prefix_lead_space
492 || in_column < next_prefix_indent + prefix_full_length)
494 c = copy_rest (f, c);
504 /* Got a suitable first line for a paragraph. */
506 prefix_indent = next_prefix_indent;
507 first_indent = in_column;
512 /* Read rest of paragraph (unless split is specified). */
515 other_indent = first_indent;
520 other_indent = in_column;
522 { /* for each line till the end of the para */
525 while (same_para (c) && in_column == other_indent);
528 other_indent = first_indent;
532 if (same_para (c) && in_column != first_indent)
534 other_indent = in_column;
536 { /* for each line till the end of the para */
539 while (same_para (c) && in_column == other_indent);
542 /* Only one line: use the secondary indent from last time if it
543 splits, or 0 if there have been no multi-line paragraphs in the
544 input so far. But if these rules make the two indents the same,
545 pick a new secondary indent. */
547 else if (other_indent == first_indent)
548 other_indent = first_indent == 0 ? DEF_INDENT : 0;
552 other_indent = first_indent;
553 while (same_para (c) && in_column == other_indent)
556 (word_limit - 1)->period = (word_limit - 1)->final = TRUE;
561 /* Copy to the output a line that failed to match the prefix, or that
562 was blank after the prefix. In the former case, C is the character
563 that failed to match the prefix. In the latter, C is \n or EOF.
564 Return the character (\n or EOF) ending the line. */
567 copy_rest (FILE *f, register int c)
569 register const char *s;
572 if (in_column > next_prefix_indent && c != '\n' && c != EOF)
574 put_space (next_prefix_indent);
575 for (s = prefix; out_column != in_column && *s; out_column++)
577 put_space (in_column - out_column);
579 while (c != '\n' && c != EOF)
587 /* Return TRUE if a line whose first non-blank character after the
588 prefix (if any) is C could belong to the current paragraph,
592 same_para (register int c)
594 return (next_prefix_indent == prefix_indent
595 && in_column >= next_prefix_indent + prefix_full_length
596 && c != '\n' && c != EOF);
599 /* Read a line from input file F, given first non-blank character C
600 after the prefix, and the following indent, and break it into words.
601 A word is a maximal non-empty string of non-white characters. A word
602 ending in [.?!]["')\]]* and followed by end-of-line or at least two
603 spaces ends a sentence, as in emacs.
605 Return the first non-blank character of the next line. */
608 get_line (FILE *f, register int c)
611 register char *end_of_parabuf;
612 register WORD *end_of_word;
614 end_of_parabuf = ¶buf[MAXCHARS];
615 end_of_word = &word[MAXWORDS - 2];
618 { /* for each word in a line */
622 word_limit->text = wptr;
625 if (wptr == end_of_parabuf)
630 while (c != EOF && !ISSPACE (c));
631 in_column += word_limit->length = wptr - word_limit->text;
632 check_punctuation (word_limit);
634 /* Scan inter-word space. */
637 c = get_space (f, c);
638 word_limit->space = in_column - start;
639 word_limit->final = (c == EOF
640 || (word_limit->period
641 && (c == '\n' || word_limit->space > 1)));
642 if (c == '\n' || c == EOF || uniform)
643 word_limit->space = word_limit->final ? 2 : 1;
644 if (word_limit == end_of_word)
651 return get_prefix (f);
654 /* Read a prefix from input file F. Return either first non-matching
655 character, or first non-blank character after the prefix. */
661 register const char *p;
664 c = get_space (f, getc (f));
665 if (prefix_length == 0)
666 next_prefix_indent = prefix_lead_space < in_column ?
667 prefix_lead_space : in_column;
670 next_prefix_indent = in_column;
671 for (p = prefix; *p != '\0'; p++)
678 c = get_space (f, c);
683 /* Read blank characters from input file F, starting with C, and keeping
684 in_column up-to-date. Return first non-blank character. */
687 get_space (FILE *f, register int c)
696 in_column = (in_column / TABWIDTH + 1) * TABWIDTH;
704 /* Set extra fields in word W describing any attached punctuation. */
707 check_punctuation (register WORD *w)
709 register const char *start, *finish;
712 finish = start + (w->length - 1);
713 w->paren = isopen (*start);
714 w->punct = ISPUNCT (*finish);
715 while (isclose (*finish) && finish > start)
717 w->period = isperiod (*finish);
720 /* Flush part of the paragraph to make room. This function is called on
721 hitting the limit on the number of words or characters. */
724 flush_paragraph (void)
731 /* In the special case where it's all one word, just flush it. */
733 if (word_limit == word)
735 printf ("%*s", wptr - parabuf, parabuf);
741 - format what you have so far as a paragraph,
742 - find a low-cost line break near the end,
744 - make that the start of the paragraph. */
748 /* Choose a good split point. */
750 split_point = word_limit;
751 best_break = MAXCOST;
752 for (w = word->next_break; w != word_limit; w = w->next_break)
754 if (w->best_cost - w->next_break->best_cost < best_break)
757 best_break = w->best_cost - w->next_break->best_cost;
759 if (best_break <= MAXCOST - LINE_CREDIT)
760 best_break += LINE_CREDIT;
762 put_paragraph (split_point);
764 /* Copy text of words down to start of parabuf -- we use memmove because
765 the source and target may overlap. */
767 memmove (parabuf, split_point->text, (size_t) (wptr - split_point->text));
768 shift = split_point->text - parabuf;
771 /* Adjust text pointers. */
773 for (w = split_point; w <= word_limit; w++)
776 /* Copy words from split_point down to word -- we use memmove because
777 the source and target may overlap. */
779 memmove ((char *) word, (char *) split_point,
780 (word_limit - split_point + 1) * sizeof (WORD));
781 word_limit -= split_point - word;
784 /* Compute the optimal formatting for the whole paragraph by computing
785 and remembering the optimal formatting for each suffix from the empty
786 one to the whole paragraph. */
791 register WORD *start, *w;
793 register COST wcost, best;
796 word_limit->best_cost = 0;
797 saved_length = word_limit->length;
798 word_limit->length = max_width; /* sentinel */
800 for (start = word_limit - 1; start >= word; start--)
803 len = start == word ? first_indent : other_indent;
805 /* At least one word, however long, in the line. */
813 /* Consider breaking before w. */
815 wcost = line_cost (w, len) + w->best_cost;
816 if (start == word && last_line_length > 0)
817 wcost += RAGGED_COST (len - last_line_length);
821 start->next_break = w;
822 start->line_length = len;
824 len += (w - 1)->space + w->length; /* w > start >= word */
826 while (len < max_width);
827 start->best_cost = best + base_cost (start);
830 word_limit->length = saved_length;
833 /* Return the constant component of the cost of breaking before the
837 base_cost (register WORD *this)
845 if ((this - 1)->period)
847 if ((this - 1)->final)
848 cost -= SENTENCE_BONUS;
850 cost += NOBREAK_COST;
852 else if ((this - 1)->punct)
854 else if (this > word + 1 && (this - 2)->final)
855 cost += WIDOW_COST ((this - 1)->length);
860 else if (this->final)
861 cost += ORPHAN_COST (this->length);
866 /* Return the component of the cost of breaking before word NEXT that
867 depends on LEN, the length of the line beginning there. */
870 line_cost (register WORD *next, register int len)
875 if (next == word_limit)
877 n = best_width - len;
878 cost = SHORT_COST (n);
879 if (next->next_break != word_limit)
881 n = len - next->line_length;
882 cost += RAGGED_COST (n);
887 /* Output to stdout a paragraph from word up to (but not including)
888 FINISH, which must be in the next_break chain from word. */
891 put_paragraph (register WORD *finish)
895 put_line (word, first_indent);
896 for (w = word->next_break; w != finish; w = w->next_break)
897 put_line (w, other_indent);
900 /* Output to stdout the line beginning with word W, beginning in column
901 INDENT, including the prefix (if any). */
904 put_line (register WORD *w, int indent)
906 register WORD *endline;
909 put_space (prefix_indent);
910 fputs (prefix, stdout);
911 out_column += prefix_length;
912 put_space (indent - out_column);
914 endline = w->next_break - 1;
915 for (; w != endline; w++)
918 put_space (w->space);
921 last_line_length = out_column;
925 /* Output to stdout the word W. */
928 put_word (register WORD *w)
930 register const char *s;
934 for (n = w->length; n != 0; n--)
936 out_column += w->length;
939 /* Output to stdout SPACE spaces, or equivalent tabs. */
942 put_space (int space)
944 register int space_target, tab_target;
946 space_target = out_column + space;
949 tab_target = space_target / TABWIDTH * TABWIDTH;
950 if (out_column + 1 < tab_target)
951 while (out_column < tab_target)
954 out_column = (out_column / TABWIDTH + 1) * TABWIDTH;
957 while (out_column < space_target)