1 /* GNU fmt -- simple text formatter.
2 Copyright (C) 94, 95, 1996 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
16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 /* Written by Ross Paterson <rap@doc.ic.ac.uk>. */
23 #include <sys/types.h>
31 # define UINT_MAX ((unsigned int) ~(unsigned int) 0)
35 # define INT_MAX ((int) (UINT_MAX >> 1))
38 /* Redefine. Otherwise, systems (Unicos for one) with headers that define
39 it to be a type get syntax errors for the variable declaration below. */
40 #define word unused_word_type
46 /* The following parameters represent the program's idea of what is
47 "best". Adjust to taste, subject to the caveats given. */
49 /* Default longest permitted line length (max_width). */
52 /* Prefer lines to be LEEWAY % shorter than the maximum width, giving
53 room for optimization. */
56 /* The default secondary indent of tagged paragraph used for unindented
57 one-line paragraphs not preceded by any multi-line paragraphs. */
60 /* Costs and bonuses are expressed as the equivalent departure from the
61 optimal line length, multiplied by 10. e.g. assigning something a
62 cost of 50 means that it is as bad as a line 5 characters too short
63 or too long. The definition of SHORT_COST(n) should not be changed.
64 However, EQUIV(n) may need tuning. */
68 #define MAXCOST (~(((COST) 1) << (8 * sizeof (COST) -1)))
70 #define SQR(n) ((n) * (n))
71 #define EQUIV(n) SQR ((COST) (n))
73 /* Cost of a filled line n chars longer or shorter than best_width. */
74 #define SHORT_COST(n) EQUIV ((n) * 10)
76 /* Cost of the difference between adjacent filled lines. */
77 #define RAGGED_COST(n) (SHORT_COST (n) / 2)
79 /* Basic cost per line. */
80 #define LINE_COST EQUIV (70)
82 /* Cost of breaking a line after the first word of a sentence, where
83 the length of the word is N. */
84 #define WIDOW_COST(n) (EQUIV (200) / ((n) + 2))
86 /* Cost of breaking a line before the last word of a sentence, where
87 the length of the word is N. */
88 #define ORPHAN_COST(n) (EQUIV (150) / ((n) + 2))
90 /* Bonus for breaking a line at the end of a sentence. */
91 #define SENTENCE_BONUS EQUIV (50)
93 /* Cost of breaking a line after a period not marking end of a sentence.
94 With the definition of sentence we are using (borrowed from emacs, see
95 get_line()) such a break would then look like a sentence break. Hence
96 we assign a very high cost -- it should be avoided unless things are
98 #define NOBREAK_COST EQUIV (600)
100 /* Bonus for breaking a line before open parenthesis. */
101 #define PAREN_BONUS EQUIV (40)
103 /* Bonus for breaking a line after other punctuation. */
104 #define PUNCT_BONUS EQUIV(40)
106 /* Credit for breaking a long paragraph one line later. */
107 #define LINE_CREDIT EQUIV(3)
109 /* Size of paragraph buffer, in words and characters. Longer paragraphs
110 are handled neatly (cf. flush_paragraph()), so there's little to gain
111 by making these larger. */
112 #define MAXWORDS 1000
113 #define MAXCHARS 5000
115 /* Extra ctype(3)-style macros. */
117 #define isopen(c) (strchr ("([`'\"", c) != NULL)
118 #define isclose(c) (strchr (")]'\"", c) != NULL)
119 #define isperiod(c) (strchr (".?!", c) != NULL)
121 /* Size of a tab stop, for expansion on input and re-introduction on
125 /* Miscellaneous definitions. */
127 typedef unsigned int bool;
133 /* Word descriptor structure. */
135 typedef struct Word WORD
;
140 /* Static attributes determined during input. */
142 const char *text
; /* the text of the word */
143 short length
; /* length of this word */
144 short space
; /* the size of the following space */
145 bool paren
:1; /* starts with open paren */
146 bool period
:1; /* ends in [.?!])* */
147 bool punct
:1; /* ends in punctuation */
148 bool final
:1; /* end of sentence */
150 /* The remaining fields are computed during the optimization. */
152 short line_length
; /* length of the best line starting here */
153 COST best_cost
; /* cost of best paragraph starting here */
154 WORD
*next_break
; /* break which achieves best_cost */
157 /* Forward declarations. */
159 static void set_prefix
__P ((char *p
));
160 static void fmt
__P ((FILE *f
));
161 static bool get_paragraph
__P ((FILE *f
));
162 static int get_line
__P ((FILE *f
, int c
));
163 static int get_prefix
__P ((FILE *f
));
164 static int get_space
__P ((FILE *f
, int c
));
165 static int copy_rest
__P ((FILE *f
, int c
));
166 static bool same_para
__P ((int c
));
167 static void flush_paragraph
__P ((void));
168 static void fmt_paragraph
__P ((void));
169 static void check_punctuation
__P ((WORD
*w
));
170 static COST base_cost
__P ((WORD
*this));
171 static COST line_cost
__P ((WORD
*next
, int len
));
172 static void put_paragraph
__P ((WORD
*finish
));
173 static void put_line
__P ((WORD
*w
, int indent
));
174 static void put_word
__P ((WORD
*w
));
175 static void put_space
__P ((int space
));
177 /* The name this program was run with. */
178 const char *program_name
;
180 /* If nonzero, display usage information and exit. */
181 static int show_help
= 0;
183 /* If nonzero, print the version on standard output and exit. */
184 static int show_version
= 0;
188 /* If TRUE, first 2 lines may have different indent (default FALSE). */
191 /* If TRUE, first 2 lines _must_ have different indent (default FALSE). */
194 /* If TRUE, each line is a paragraph on its own (default FALSE). */
197 /* If TRUE, don't preserve inter-word spacing (default FALSE). */
200 /* Prefix minus leading and trailing spaces (default ""). */
201 static const char *prefix
;
203 /* User-supplied maximum line width (default WIDTH). The only output
205 longer than this will each comprise a single word. */
206 static int max_width
;
208 /* Values derived from the option values. */
210 /* The length of prefix minus leading space. */
211 static int prefix_full_length
;
213 /* The length of the leading space trimmed from the prefix. */
214 static int prefix_lead_space
;
216 /* The length of prefix minus leading and trailing space. */
217 static int prefix_length
;
219 /* The preferred width of text lines, set to LEEWAY % less than max_width. */
220 static int best_width
;
222 /* Dynamic variables. */
224 /* Start column of the character most recently read from the input file. */
225 static int in_column
;
227 /* Start column of the next character to be written to stdout. */
228 static int out_column
;
230 /* Space for the paragraph text -- longer paragraphs are handled neatly
231 (cf. flush_paragraph()). */
232 static char parabuf
[MAXCHARS
];
234 /* A pointer into parabuf, indicating the first unused character position. */
237 /* The words of a paragraph -- longer paragraphs are handled neatly
238 (cf. flush_paragraph()). */
239 static WORD word
[MAXWORDS
];
241 /* A pointer into the above word array, indicating the first position
242 after the last complete word. Sometimes it will point at an incomplete
244 static WORD
*word_limit
;
246 /* If TRUE, current input file contains tab characters, and so tabs can be
247 used for white space on output. */
250 /* Space before trimmed prefix on each line of the current paragraph. */
251 static int prefix_indent
;
253 /* Indentation of the first line of the current paragraph. */
254 static int first_indent
;
256 /* Indentation of other lines of the current paragraph */
257 static int other_indent
;
259 /* To detect the end of a paragraph, we need to look ahead to the first
260 non-blank character after the prefix on the next line, or the first
261 character on the following line that failed to match the prefix.
262 We can reconstruct the lookahead from that character (next_char), its
263 position on the line (in_column) and the amount of space before the
264 prefix (next_prefix_indent). See get_paragraph() and copy_rest(). */
266 /* The last character read from the input file. */
267 static int next_char
;
269 /* The space before the trimmed prefix (or part of it) on the next line
270 after the current paragraph. */
271 static int next_prefix_indent
;
273 /* If nonzero, the length of the last line output in the current
274 paragraph, used to charge for raggedness at the split point for long
275 paragraphs chosen by fmt_paragraph(). */
276 static int last_line_length
;
282 fprintf (stderr
, _("Try `%s --help' for more information.\n"),
286 printf (_("Usage: %s [-DIGITS] [OPTION]... [FILE]...\n"), program_name
);
288 Reformat each paragraph in the FILE(s), writing to standard output.\n\
289 If no FILE or if FILE is `-', read standard input.\n\
291 Mandatory arguments to long options are mandatory for short options too.\n\
292 -c, --crown-margin preserve indentation of first two lines\n\
293 -s, --split-only split long lines, but do not refill\n\
294 -t, --tagged-paragraph indentation of first line different from second\n\
295 -u, --uniform-spacing one space between words, two after sentences\n\
296 -w, --width=NUMBER maximum line width (default of 75 columns)\n\
297 -p, --prefix=STRING combine only lines having STRING as prefix\n\
298 --help display this help and exit\n\
299 --version output version information and exit\n\
301 In -wNUMBER, the letter `w' may be omitted.\n"),
304 exit (status
== 0 ? EXIT_SUCCESS
: EXIT_FAILURE
);
307 /* Decode options and launch execution. */
309 static const struct option long_options
[] =
311 {"crown-margin", no_argument
, NULL
, 'c'},
312 {"help", no_argument
, &show_help
, 1},
313 {"prefix", required_argument
, NULL
, 'p'},
314 {"split-only", no_argument
, NULL
, 's'},
315 {"tagged-paragraph", no_argument
, NULL
, 't'},
316 {"uniform-spacing", no_argument
, NULL
, 'u'},
317 {"version", no_argument
, &show_version
, 1},
318 {"width", required_argument
, NULL
, 'w'},
323 main (register int argc
, register char **argv
)
328 program_name
= argv
[0];
329 setlocale (LC_ALL
, "");
330 bindtextdomain (PACKAGE
, LOCALEDIR
);
331 textdomain (PACKAGE
);
333 crown
= tagged
= split
= uniform
= FALSE
;
336 prefix_length
= prefix_lead_space
= prefix_full_length
= 0;
338 if (argc
> 1 && argv
[1][0] == '-' && ISDIGIT (argv
[1][1]))
341 /* Old option syntax; a dash followed by one or more digits.
342 Move past the number. */
343 for (++argv
[1]; ISDIGIT (*argv
[1]); ++argv
[1])
345 /* FIXME: use strtol to detect overflow. */
346 max_width
= max_width
* 10 + *argv
[1] - '0';
348 /* Make the options we just parsed invisible to getopt. */
354 while ((optchar
= getopt_long (argc
, argv
, "0123456789cstuw:p:",
384 if (xstrtol (optarg
, NULL
, 10, &tmp_long
, NULL
) != LONGINT_OK
385 || tmp_long
<= 0 || tmp_long
> INT_MAX
)
386 error (EXIT_FAILURE
, 0, _("invalid line number increment: `%s'"),
388 max_width
= (int) tmp_long
;
400 printf ("fmt - %s\n", PACKAGE_VERSION
);
407 best_width
= max_width
* (2 * (100 - LEEWAY
) + 1) / 200;
412 for (; optind
< argc
; optind
++)
413 if (strcmp (argv
[optind
], "-") == 0)
417 infile
= fopen (argv
[optind
], "r");
424 error (0, errno
, argv
[optind
]);
430 /* Trim space from the front and back of the string P, yielding the prefix,
431 and record the lengths of the prefix and the space trimmed. */
434 set_prefix (register char *p
)
438 prefix_lead_space
= 0;
445 prefix_full_length
= strlen (p
);
446 s
= p
+ prefix_full_length
;
447 while (s
> p
&& s
[-1] == ' ')
450 prefix_length
= s
- p
;
453 /* read file F and send formatted output to stdout. */
460 next_char
= get_prefix (f
);
461 while (get_paragraph (f
))
464 put_paragraph (word_limit
);
468 /* Read a paragraph from input file F. A paragraph consists of a
469 maximal number of non-blank (excluding any prefix) lines subject to:
470 * In split mode, a paragraph is a single non-blank line.
471 * In crown mode, the second and subsequent lines must have the
472 same indentation, but possibly different from the indent of the
474 * Tagged mode is similar, but the first and second lines must have
475 different indentations.
476 * Otherwise, all lines of a paragraph must have the same indent.
477 If a prefix is in effect, it must be present at the same indent for
478 each line in the paragraph.
480 Return FALSE if end-of-file was encountered before the start of a
481 paragraph, else TRUE. */
484 get_paragraph (FILE *f
)
488 last_line_length
= 0;
491 /* Scan (and copy) blank lines, and lines not introduced by the prefix. */
493 while (c
== '\n' || c
== EOF
494 || next_prefix_indent
< prefix_lead_space
495 || in_column
< next_prefix_indent
+ prefix_full_length
)
497 c
= copy_rest (f
, c
);
507 /* Got a suitable first line for a paragraph. */
509 prefix_indent
= next_prefix_indent
;
510 first_indent
= in_column
;
515 /* Read rest of paragraph (unless split is specified). */
518 other_indent
= first_indent
;
523 other_indent
= in_column
;
525 { /* for each line till the end of the para */
528 while (same_para (c
) && in_column
== other_indent
);
531 other_indent
= first_indent
;
535 if (same_para (c
) && in_column
!= first_indent
)
537 other_indent
= in_column
;
539 { /* for each line till the end of the para */
542 while (same_para (c
) && in_column
== other_indent
);
545 /* Only one line: use the secondary indent from last time if it
546 splits, or 0 if there have been no multi-line paragraphs in the
547 input so far. But if these rules make the two indents the same,
548 pick a new secondary indent. */
550 else if (other_indent
== first_indent
)
551 other_indent
= first_indent
== 0 ? DEF_INDENT
: 0;
555 other_indent
= first_indent
;
556 while (same_para (c
) && in_column
== other_indent
)
559 (word_limit
- 1)->period
= (word_limit
- 1)->final
= TRUE
;
564 /* Copy to the output a line that failed to match the prefix, or that
565 was blank after the prefix. In the former case, C is the character
566 that failed to match the prefix. In the latter, C is \n or EOF.
567 Return the character (\n or EOF) ending the line. */
570 copy_rest (FILE *f
, register int c
)
572 register const char *s
;
575 if (in_column
> next_prefix_indent
&& c
!= '\n' && c
!= EOF
)
577 put_space (next_prefix_indent
);
578 for (s
= prefix
; out_column
!= in_column
; out_column
++)
581 while (c
!= '\n' && c
!= EOF
)
589 /* Return TRUE if a line whose first non-blank character after the
590 prefix (if any) is C could belong to the current paragraph,
594 same_para (register int c
)
596 return (next_prefix_indent
== prefix_indent
597 && in_column
>= next_prefix_indent
+ prefix_full_length
598 && c
!= '\n' && c
!= EOF
);
601 /* Read a line from input file F, given first non-blank character C
602 after the prefix, and the following indent, and break it into words.
603 A word is a maximal non-empty string of non-white characters. A word
604 ending in [.?!]["')\]]* and followed by end-of-line or at least two
605 spaces ends a sentence, as in emacs.
607 Return the first non-blank character of the next line. */
610 get_line (FILE *f
, register int c
)
613 register char *end_of_parabuf
;
614 register WORD
*end_of_word
;
616 end_of_parabuf
= ¶buf
[MAXCHARS
];
617 end_of_word
= &word
[MAXWORDS
- 2];
620 { /* for each word in a line */
624 word_limit
->text
= wptr
;
627 if (wptr
== end_of_parabuf
)
632 while (c
!= EOF
&& !isspace (c
));
633 in_column
+= word_limit
->length
= wptr
- word_limit
->text
;
634 check_punctuation (word_limit
);
636 /* Scan inter-word space. */
639 c
= get_space (f
, c
);
640 word_limit
->space
= in_column
- start
;
641 word_limit
->final
= (c
== EOF
642 || (word_limit
->period
643 && (c
== '\n' || word_limit
->space
> 1)));
644 if (c
== '\n' || c
== EOF
|| uniform
)
645 word_limit
->space
= word_limit
->final
? 2 : 1;
646 if (word_limit
== end_of_word
)
653 return get_prefix (f
);
656 /* Read a prefix from input file F. Return either first non-matching
657 character, or first non-blank character after the prefix. */
663 register const char *p
;
666 c
= get_space (f
, getc (f
));
667 if (prefix_length
== 0)
668 next_prefix_indent
= prefix_lead_space
< in_column
?
669 prefix_lead_space
: in_column
;
672 next_prefix_indent
= in_column
;
673 for (p
= prefix
; *p
!= '\0'; p
++)
680 c
= get_space (f
, c
);
685 /* Read blank characters from input file F, starting with C, and keeping
686 in_column up-to-date. Return first non-blank character. */
689 get_space (FILE *f
, register int c
)
698 in_column
= (in_column
/ TABWIDTH
+ 1) * TABWIDTH
;
706 /* Set extra fields in word W describing any attached punctuation. */
709 check_punctuation (register WORD
*w
)
711 register const char *start
, *finish
;
714 finish
= start
+ (w
->length
- 1);
715 w
->paren
= isopen (*start
);
716 w
->punct
= ispunct (*finish
);
717 while (isclose (*finish
) && finish
> start
)
719 w
->period
= isperiod (*finish
);
722 /* Flush part of the paragraph to make room. This function is called on
723 hitting the limit on the number of words or characters. */
726 flush_paragraph (void)
733 /* In the special case where it's all one word, just flush it. */
735 if (word_limit
== word
)
737 printf ("%*s", wptr
- parabuf
, parabuf
);
743 - format what you have so far as a paragraph,
744 - find a low-cost line break near the end,
746 - make that the start of the paragraph. */
750 /* Choose a good split point. */
752 split_point
= word_limit
;
753 best_break
= MAXCOST
;
754 for (w
= word
->next_break
; w
!= word_limit
; w
= w
->next_break
)
756 if (w
->best_cost
- w
->next_break
->best_cost
< best_break
)
759 best_break
= w
->best_cost
- w
->next_break
->best_cost
;
761 if (best_break
<= MAXCOST
- LINE_CREDIT
)
762 best_break
+= LINE_CREDIT
;
764 put_paragraph (split_point
);
766 /* Copy text of words down to start of parabuf -- we use memmove because
767 the source and target may overlap. */
769 memmove (parabuf
, split_point
->text
, (size_t) (wptr
- split_point
->text
));
770 shift
= split_point
->text
- parabuf
;
773 /* Adjust text pointers. */
775 for (w
= split_point
; w
<= word_limit
; w
++)
778 /* Copy words from split_point down to word -- we use memmove because
779 the source and target may overlap. */
781 memmove ((char *) word
, (char *) split_point
,
782 (word_limit
- split_point
+ 1) * sizeof (WORD
));
783 word_limit
-= split_point
- word
;
786 /* Compute the optimal formatting for the whole paragraph by computing
787 and remembering the optimal formatting for each suffix from the empty
788 one to the whole paragraph. */
793 register WORD
*start
, *w
;
795 register COST wcost
, best
;
798 word_limit
->best_cost
= 0;
799 saved_length
= word_limit
->length
;
800 word_limit
->length
= max_width
; /* sentinel */
802 for (start
= word_limit
- 1; start
>= word
; start
--)
805 len
= start
== word
? first_indent
: other_indent
;
807 /* At least one word, however long, in the line. */
815 /* Consider breaking before w. */
817 wcost
= line_cost (w
, len
) + w
->best_cost
;
818 if (start
== word
&& last_line_length
> 0)
819 wcost
+= RAGGED_COST (len
- last_line_length
);
823 start
->next_break
= w
;
824 start
->line_length
= len
;
826 len
+= (w
- 1)->space
+ w
->length
; /* w > start >= word */
828 while (len
< max_width
);
829 start
->best_cost
= best
+ base_cost (start
);
832 word_limit
->length
= saved_length
;
835 /* Return the constant component of the cost of breaking before the
839 base_cost (register WORD
*this)
847 if ((this - 1)->period
)
849 if ((this - 1)->final
)
850 cost
-= SENTENCE_BONUS
;
852 cost
+= NOBREAK_COST
;
854 else if ((this - 1)->punct
)
856 else if (this > word
+ 1 && (this - 2)->final
)
857 cost
+= WIDOW_COST ((this - 1)->length
);
862 else if (this->final
)
863 cost
+= ORPHAN_COST (this->length
);
868 /* Return the component of the cost of breaking before word NEXT that
869 depends on LEN, the length of the line beginning there. */
872 line_cost (register WORD
*next
, register int len
)
877 if (next
== word_limit
)
879 n
= best_width
- len
;
880 cost
= SHORT_COST (n
);
881 if (next
->next_break
!= word_limit
)
883 n
= len
- next
->line_length
;
884 cost
+= RAGGED_COST (n
);
889 /* Output to stdout a paragraph from word up to (but not including)
890 FINISH, which must be in the next_break chain from word. */
893 put_paragraph (register WORD
*finish
)
897 put_line (word
, first_indent
);
898 for (w
= word
->next_break
; w
!= finish
; w
= w
->next_break
)
899 put_line (w
, other_indent
);
902 /* Output to stdout the line beginning with word W, beginning in column
903 INDENT, including the prefix (if any). */
906 put_line (register WORD
*w
, int indent
)
908 register WORD
*endline
;
911 put_space (prefix_indent
);
912 fputs (prefix
, stdout
);
913 out_column
+= prefix_length
;
914 put_space (indent
- out_column
);
916 endline
= w
->next_break
- 1;
917 for (; w
!= endline
; w
++)
920 put_space (w
->space
);
923 last_line_length
= out_column
;
927 /* Output to stdout the word W. */
930 put_word (register WORD
*w
)
932 register const char *s
;
936 for (n
= w
->length
; n
!= 0; n
--)
938 out_column
+= w
->length
;
941 /* Output to stdout SPACE spaces, or equivalent tabs. */
944 put_space (int space
)
946 register int space_target
, tab_target
;
948 space_target
= out_column
+ space
;
951 tab_target
= space_target
/ TABWIDTH
* TABWIDTH
;
952 if (out_column
+ 1 < tab_target
)
953 while (out_column
< tab_target
)
956 out_column
= (out_column
/ TABWIDTH
+ 1) * TABWIDTH
;
959 while (out_column
< space_target
)