1 /* diff - compare files line by line
3 Copyright (C) 1988, 1989, 1992, 1993, 1994, 1996, 1998, 2001, 2002,
4 2004 Free Software Foundation, Inc.
6 This file is part of GNU DIFF.
8 GNU DIFF is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GNU DIFF is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16 See the GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU DIFF; see the file COPYING.
20 If not, write to the Free Software Foundation,
21 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
32 #include <file-type.h>
35 #include <hard-locale.h>
40 #include <version-etc.h>
43 #ifndef GUTTER_WIDTH_MINIMUM
44 # define GUTTER_WIDTH_MINIMUM 3
49 char *regexps; /* chars representing disjunction of the regexps */
50 size_t len; /* chars used in `regexps' */
51 size_t size; /* size malloc'ed for `regexps'; 0 if not malloc'ed */
52 bool multiple_regexps;/* Does `regexps' represent a disjunction? */
53 struct re_pattern_buffer *buf;
56 static int compare_files (struct comparison const *, char const *, char const *);
57 static void add_regexp (struct regexp_list *, char const *);
58 static void summarize_regexp_list (struct regexp_list *);
59 static void specify_style (enum output_style);
60 static void specify_value (char const **, char const *, char const *);
61 static void try_help (char const *, char const *) __attribute__((noreturn));
62 static void check_stdout (void);
63 static void usage (void);
65 /* If comparing directories, compare their common subdirectories
67 static bool recursive;
69 /* In context diffs, show previous lines that match these regexps. */
70 static struct regexp_list function_regexp_list;
72 /* Ignore changes affecting only lines that match these regexps. */
73 static struct regexp_list ignore_regexp_list;
76 /* Use binary I/O when reading and writing data (--binary).
77 On POSIX hosts, this has no effect. */
80 enum { binary = true };
83 /* When comparing directories, if a file appears only in one
84 directory, treat it as present but empty in the other (-N).
85 Then `patch' would create the file with appropriate contents. */
88 /* When comparing directories, if a file appears only in the second
89 directory of the two, treat it as present but empty in the other
90 (--unidirectional-new-file).
91 Then `patch' would create the file with appropriate contents. */
92 static bool unidirectional_new_file;
94 /* Report files compared that are the same (-s).
95 Normally nothing is output when that happens. */
96 static bool report_identical_files;
99 /* Return a string containing the command options with which diff was invoked.
100 Spaces appear between what were separate ARGV-elements.
101 There is a space at the beginning but none at the end.
102 If there were no options, the result is an empty string.
104 Arguments: OPTIONVEC, a vector containing separate ARGV-elements, and COUNT,
105 the length of that vector. */
108 option_list (char **optionvec, int count)
115 for (i = 0; i < count; i++)
116 size += 1 + quote_system_arg ((char *) 0, optionvec[i]);
118 p = result = xmalloc (size);
120 for (i = 0; i < count; i++)
123 p += quote_system_arg (p, optionvec[i]);
131 /* Return an option value suitable for add_exclude. */
134 exclude_options (void)
136 return EXCLUDE_WILDCARDS | (ignore_file_name_case ? FNM_CASEFOLD : 0);
139 static char const shortopts[] =
140 "0123456789abBcC:dD:eEfF:hHiI:lL:nNpPqrsS:tTuU:vwW:x:X:y";
142 /* Values for long options that do not have single-letter equivalents. */
145 BINARY_OPTION = CHAR_MAX + 1,
148 HORIZON_LINES_OPTION,
149 IGNORE_FILE_NAME_CASE_OPTION,
150 INHIBIT_HUNK_MERGE_OPTION,
153 NO_IGNORE_FILE_NAME_CASE_OPTION,
155 SDIFF_MERGE_ASSIST_OPTION,
156 STRIP_TRAILING_CR_OPTION,
157 SUPPRESS_COMMON_LINES_OPTION,
161 /* These options must be in sequence. */
162 UNCHANGED_LINE_FORMAT_OPTION,
163 OLD_LINE_FORMAT_OPTION,
164 NEW_LINE_FORMAT_OPTION,
166 /* These options must be in sequence. */
167 UNCHANGED_GROUP_FORMAT_OPTION,
168 OLD_GROUP_FORMAT_OPTION,
169 NEW_GROUP_FORMAT_OPTION,
170 CHANGED_GROUP_FORMAT_OPTION
173 static char const group_format_option[][sizeof "--unchanged-group-format"] =
175 "--unchanged-group-format",
176 "--old-group-format",
177 "--new-group-format",
178 "--changed-group-format"
181 static char const line_format_option[][sizeof "--unchanged-line-format"] =
183 "--unchanged-line-format",
188 static struct option const longopts[] =
190 {"binary", 0, 0, BINARY_OPTION},
191 {"brief", 0, 0, 'q'},
192 {"changed-group-format", 1, 0, CHANGED_GROUP_FORMAT_OPTION},
193 {"context", 2, 0, 'C'},
195 {"exclude", 1, 0, 'x'},
196 {"exclude-from", 1, 0, 'X'},
197 {"expand-tabs", 0, 0, 't'},
198 {"forward-ed", 0, 0, 'f'},
199 {"from-file", 1, 0, FROM_FILE_OPTION},
200 {"help", 0, 0, HELP_OPTION},
201 {"horizon-lines", 1, 0, HORIZON_LINES_OPTION},
202 {"ifdef", 1, 0, 'D'},
203 {"ignore-all-space", 0, 0, 'w'},
204 {"ignore-blank-lines", 0, 0, 'B'},
205 {"ignore-case", 0, 0, 'i'},
206 {"ignore-file-name-case", 0, 0, IGNORE_FILE_NAME_CASE_OPTION},
207 {"ignore-matching-lines", 1, 0, 'I'},
208 {"ignore-space-change", 0, 0, 'b'},
209 {"ignore-tab-expansion", 0, 0, 'E'},
210 {"inhibit-hunk-merge", 0, 0, INHIBIT_HUNK_MERGE_OPTION},
211 {"initial-tab", 0, 0, 'T'},
212 {"label", 1, 0, 'L'},
213 {"left-column", 0, 0, LEFT_COLUMN_OPTION},
214 {"line-format", 1, 0, LINE_FORMAT_OPTION},
215 {"minimal", 0, 0, 'd'},
216 {"new-file", 0, 0, 'N'},
217 {"new-group-format", 1, 0, NEW_GROUP_FORMAT_OPTION},
218 {"new-line-format", 1, 0, NEW_LINE_FORMAT_OPTION},
219 {"no-ignore-file-name-case", 0, 0, NO_IGNORE_FILE_NAME_CASE_OPTION},
220 {"normal", 0, 0, NORMAL_OPTION},
221 {"old-group-format", 1, 0, OLD_GROUP_FORMAT_OPTION},
222 {"old-line-format", 1, 0, OLD_LINE_FORMAT_OPTION},
223 {"paginate", 0, 0, 'l'},
225 {"recursive", 0, 0, 'r'},
226 {"report-identical-files", 0, 0, 's'},
227 {"sdiff-merge-assist", 0, 0, SDIFF_MERGE_ASSIST_OPTION},
228 {"show-c-function", 0, 0, 'p'},
229 {"show-function-line", 1, 0, 'F'},
230 {"side-by-side", 0, 0, 'y'},
231 {"speed-large-files", 0, 0, 'H'},
232 {"starting-file", 1, 0, 'S'},
233 {"strip-trailing-cr", 0, 0, STRIP_TRAILING_CR_OPTION},
234 {"suppress-common-lines", 0, 0, SUPPRESS_COMMON_LINES_OPTION},
235 {"tabsize", 1, 0, TABSIZE_OPTION},
237 {"to-file", 1, 0, TO_FILE_OPTION},
238 {"unchanged-group-format", 1, 0, UNCHANGED_GROUP_FORMAT_OPTION},
239 {"unchanged-line-format", 1, 0, UNCHANGED_LINE_FORMAT_OPTION},
240 {"unidirectional-new-file", 0, 0, 'P'},
241 {"unified", 2, 0, 'U'},
242 {"version", 0, 0, 'v'},
243 {"width", 1, 0, 'W'},
248 main (int argc, char **argv)
250 int exit_status = EXIT_SUCCESS;
255 bool explicit_context = false;
257 bool show_c_function = false;
258 char const *from_file = 0;
259 char const *to_file = 0;
263 /* Do our initializations. */
265 initialize_main (&argc, &argv);
266 program_name = argv[0];
267 setlocale (LC_ALL, "");
268 bindtextdomain (PACKAGE, LOCALEDIR);
269 textdomain (PACKAGE);
271 function_regexp_list.buf = &function_regexp;
272 ignore_regexp_list.buf = &ignore_regexp;
273 re_set_syntax (RE_SYNTAX_GREP | RE_NO_POSIX_BACKTRACKING);
274 excluded = new_exclude ();
276 /* Decode the options. */
278 while ((c = getopt_long (argc, argv, shortopts, longopts, 0)) != -1)
295 if (! ISDIGIT (prev))
297 else if (LIN_MAX / 10 < ocontext
298 || ((ocontext = 10 * ocontext + c - '0') < 0))
307 if (ignore_white_space < IGNORE_SPACE_CHANGE)
308 ignore_white_space = IGNORE_SPACE_CHANGE;
312 ignore_blank_lines = true;
320 numval = strtoumax (optarg, &numend, 10);
322 try_help ("invalid context length `%s'", optarg);
323 if (LIN_MAX < numval)
329 specify_style (c == 'U' ? OUTPUT_UNIFIED : OUTPUT_CONTEXT);
330 if (context < numval)
332 explicit_context = true;
337 specify_style (OUTPUT_CONTEXT);
347 specify_style (OUTPUT_IFDEF);
349 static char const C_ifdef_group_formats[] =
350 "%%=%c#ifndef %s\n%%<#endif /* ! %s */\n%c#ifdef %s\n%%>#endif /* %s */\n%c#ifndef %s\n%%<#else /* %s */\n%%>#endif /* %s */\n";
351 char *b = xmalloc (sizeof C_ifdef_group_formats
352 + 7 * strlen (optarg) - 14 /* 7*"%s" */
353 - 8 /* 5*"%%" + 3*"%c" */);
354 sprintf (b, C_ifdef_group_formats,
358 optarg, optarg, optarg);
359 for (i = 0; i < sizeof group_format / sizeof *group_format; i++)
361 specify_value (&group_format[i], b, "-D");
368 specify_style (OUTPUT_ED);
372 if (ignore_white_space < IGNORE_TAB_EXPANSION)
373 ignore_white_space = IGNORE_TAB_EXPANSION;
377 specify_style (OUTPUT_FORWARD_ED);
381 add_regexp (&function_regexp_list, optarg);
385 /* Split the files into chunks for faster processing.
386 Usually does not change the result.
388 This currently has no effect. */
392 speed_large_files = true;
400 add_regexp (&ignore_regexp_list, optarg);
405 try_help ("pagination not supported on this host", 0);
408 /* Pagination requires forking and waiting, and
409 System V fork+wait does not work if SIGCHLD is ignored. */
410 signal (SIGCHLD, SIG_DFL);
416 file_label[0] = optarg;
417 else if (!file_label[1])
418 file_label[1] = optarg;
420 fatal ("too many file label options");
424 specify_style (OUTPUT_RCS);
432 show_c_function = true;
433 add_regexp (&function_regexp_list, "^[[:alpha:]$_]");
437 unidirectional_new_file = true;
449 report_identical_files = true;
453 specify_value (&starting_file, optarg, "-S");
465 specify_style (OUTPUT_UNIFIED);
471 version_etc (stdout, "diff", PACKAGE_NAME, PACKAGE_VERSION,
472 "Paul Eggert", "Mike Haertel", "David Hayes",
473 "Richard Stallman", "Len Tower", (char *) 0);
478 ignore_white_space = IGNORE_ALL_SPACE;
482 add_exclude (excluded, optarg, exclude_options ());
486 if (add_exclude_file (add_exclude, excluded, optarg,
487 exclude_options (), '\n'))
488 pfatal_with_name (optarg);
492 specify_style (OUTPUT_SDIFF);
496 numval = strtoumax (optarg, &numend, 10);
497 if (! (0 < numval && numval <= SIZE_MAX) || *numend)
498 try_help ("invalid width `%s'", optarg);
502 fatal ("conflicting width options");
510 set_binary_mode (STDOUT_FILENO, true);
514 case FROM_FILE_OPTION:
515 specify_value (&from_file, optarg, "--from-file");
523 case HORIZON_LINES_OPTION:
524 numval = strtoumax (optarg, &numend, 10);
526 try_help ("invalid horizon length `%s'", optarg);
527 horizon_lines = MAX (horizon_lines, MIN (numval, LIN_MAX));
530 case IGNORE_FILE_NAME_CASE_OPTION:
531 ignore_file_name_case = true;
534 case INHIBIT_HUNK_MERGE_OPTION:
535 /* This option is obsolete, but accept it for backward
539 case LEFT_COLUMN_OPTION:
543 case LINE_FORMAT_OPTION:
544 specify_style (OUTPUT_IFDEF);
545 for (i = 0; i < sizeof line_format / sizeof *line_format; i++)
546 specify_value (&line_format[i], optarg, "--line-format");
549 case NO_IGNORE_FILE_NAME_CASE_OPTION:
550 ignore_file_name_case = false;
554 specify_style (OUTPUT_NORMAL);
557 case SDIFF_MERGE_ASSIST_OPTION:
558 specify_style (OUTPUT_SDIFF);
559 sdiff_merge_assist = true;
562 case STRIP_TRAILING_CR_OPTION:
563 strip_trailing_cr = true;
566 case SUPPRESS_COMMON_LINES_OPTION:
567 suppress_common_lines = true;
571 numval = strtoumax (optarg, &numend, 10);
572 if (! (0 < numval && numval <= SIZE_MAX) || *numend)
573 try_help ("invalid tabsize `%s'", optarg);
574 if (tabsize != numval)
577 fatal ("conflicting tabsize options");
583 specify_value (&to_file, optarg, "--to-file");
586 case UNCHANGED_LINE_FORMAT_OPTION:
587 case OLD_LINE_FORMAT_OPTION:
588 case NEW_LINE_FORMAT_OPTION:
589 specify_style (OUTPUT_IFDEF);
590 c -= UNCHANGED_LINE_FORMAT_OPTION;
591 specify_value (&line_format[c], optarg, line_format_option[c]);
594 case UNCHANGED_GROUP_FORMAT_OPTION:
595 case OLD_GROUP_FORMAT_OPTION:
596 case NEW_GROUP_FORMAT_OPTION:
597 case CHANGED_GROUP_FORMAT_OPTION:
598 specify_style (OUTPUT_IFDEF);
599 c -= UNCHANGED_GROUP_FORMAT_OPTION;
600 specify_value (&group_format[c], optarg, group_format_option[c]);
609 if (output_style == OUTPUT_UNSPECIFIED)
613 specify_style (OUTPUT_CONTEXT);
618 specify_style (OUTPUT_NORMAL);
621 if (output_style != OUTPUT_CONTEXT || hard_locale (LC_TIME))
624 time_format = "%Y-%m-%d %H:%M:%S.%N %z";
626 time_format = "%Y-%m-%d %H:%M:%S %z";
631 /* See POSIX 1003.1-2001 for this format. */
632 time_format = "%a %b %e %T %Y";
637 bool modern_usage = 200112 <= posix2_version ();
639 if ((output_style == OUTPUT_CONTEXT
640 || output_style == OUTPUT_UNIFIED)
641 && (context < ocontext
642 || (ocontext < context && ! explicit_context)))
647 _("`-%ld' option is obsolete; use `-%c %ld'"),
649 output_style == OUTPUT_CONTEXT ? 'C' : 'U',
650 (long int) ocontext);
659 error (0, 0, _("`-%ld' option is obsolete; omit it"),
660 (long int) ocontext);
672 /* Maximize first the half line width, and then the gutter width,
673 according to the following constraints:
675 1. Two half lines plus a gutter must fit in a line.
676 2. If the half line width is nonzero:
677 a. The gutter width is at least GUTTER_WIDTH_MINIMUM.
678 b. If tabs are not expanded to spaces,
679 a half line plus a gutter is an integral number of tabs,
680 so that tabs in the right column line up. */
682 intmax_t t = expand_tabs ? 1 : tabsize;
684 intmax_t off = (w + t + GUTTER_WIDTH_MINIMUM) / (2 * t) * t;
685 sdiff_half_width = MAX (0, MIN (off - GUTTER_WIDTH_MINIMUM, w - off)),
686 sdiff_column2_offset = sdiff_half_width ? off : w;
689 /* Make the horizon at least as large as the context, so that
690 shift_boundaries has more freedom to shift the first and last hunks. */
691 if (horizon_lines < context)
692 horizon_lines = context;
694 summarize_regexp_list (&function_regexp_list);
695 summarize_regexp_list (&ignore_regexp_list);
697 if (output_style == OUTPUT_IFDEF)
699 for (i = 0; i < sizeof line_format / sizeof *line_format; i++)
701 line_format[i] = "%l\n";
702 if (!group_format[OLD])
704 = group_format[CHANGED] ? group_format[CHANGED] : "%<";
705 if (!group_format[NEW])
707 = group_format[CHANGED] ? group_format[CHANGED] : "%>";
708 if (!group_format[UNCHANGED])
709 group_format[UNCHANGED] = "%=";
710 if (!group_format[CHANGED])
711 group_format[CHANGED] = concat (group_format[OLD],
712 group_format[NEW], "");
715 no_diff_means_no_output =
716 (output_style == OUTPUT_IFDEF ?
717 (!*group_format[UNCHANGED]
718 || (strcmp (group_format[UNCHANGED], "%=") == 0
719 && !*line_format[UNCHANGED]))
720 : (output_style != OUTPUT_SDIFF) | suppress_common_lines);
722 files_can_be_treated_as_binary =
724 & ~ (ignore_blank_lines | ignore_case | strip_trailing_cr
725 | (ignore_regexp_list.regexps || ignore_white_space)));
727 switch_string = option_list (argv + 1, optind - 1);
732 fatal ("--from-file and --to-file both specified");
734 for (; optind < argc; optind++)
736 int status = compare_files ((struct comparison *) 0,
737 from_file, argv[optind]);
738 if (exit_status < status)
739 exit_status = status;
745 for (; optind < argc; optind++)
747 int status = compare_files ((struct comparison *) 0,
748 argv[optind], to_file);
749 if (exit_status < status)
750 exit_status = status;
754 if (argc - optind != 2)
756 if (argc - optind < 2)
757 try_help ("missing operand after `%s'", argv[argc - 1]);
759 try_help ("extra operand `%s'", argv[optind + 2]);
762 exit_status = compare_files ((struct comparison *) 0,
763 argv[optind], argv[optind + 1]);
767 /* Print any messages that were saved up for last. */
768 print_message_queue ();
775 /* Append to REGLIST the regexp PATTERN. */
778 add_regexp (struct regexp_list *reglist, char const *pattern)
780 size_t patlen = strlen (pattern);
781 char const *m = re_compile_pattern (pattern, patlen, reglist->buf);
784 error (0, 0, "%s: %s", pattern, m);
787 char *regexps = reglist->regexps;
788 size_t len = reglist->len;
789 bool multiple_regexps = reglist->multiple_regexps = regexps != 0;
790 size_t newlen = reglist->len = len + 2 * multiple_regexps + patlen;
791 size_t size = reglist->size;
799 while (size <= newlen);
801 reglist->size = size;
802 reglist->regexps = regexps = xrealloc (regexps, size);
804 if (multiple_regexps)
806 regexps[len++] = '\\';
807 regexps[len++] = '|';
809 memcpy (regexps + len, pattern, patlen + 1);
813 /* Ensure that REGLIST represents the disjunction of its regexps.
814 This is done here, rather than earlier, to avoid O(N^2) behavior. */
817 summarize_regexp_list (struct regexp_list *reglist)
819 if (reglist->regexps)
821 /* At least one regexp was specified. Allocate a fastmap for it. */
822 reglist->buf->fastmap = xmalloc (1 << CHAR_BIT);
823 if (reglist->multiple_regexps)
825 /* Compile the disjunction of the regexps.
826 (If just one regexp was specified, it is already compiled.) */
827 char const *m = re_compile_pattern (reglist->regexps, reglist->len,
830 error (EXIT_TROUBLE, 0, "%s: %s", reglist->regexps, m);
836 try_help (char const *reason_msgid, char const *operand)
839 error (0, 0, _(reason_msgid), operand);
840 error (EXIT_TROUBLE, 0, _("Try `%s --help' for more information."),
849 fatal ("write failed");
850 else if (fclose (stdout) != 0)
851 pfatal_with_name (_("standard output"));
854 static char const * const option_help_msgid[] = {
855 N_("Compare files line by line."),
857 N_("-i --ignore-case Ignore case differences in file contents."),
858 N_("--ignore-file-name-case Ignore case when comparing file names."),
859 N_("--no-ignore-file-name-case Consider case when comparing file names."),
860 N_("-E --ignore-tab-expansion Ignore changes due to tab expansion."),
861 N_("-b --ignore-space-change Ignore changes in the amount of white space."),
862 N_("-w --ignore-all-space Ignore all white space."),
863 N_("-B --ignore-blank-lines Ignore changes whose lines are all blank."),
864 N_("-I RE --ignore-matching-lines=RE Ignore changes whose lines all match RE."),
865 N_("--strip-trailing-cr Strip trailing carriage return on input."),
867 N_("--binary Read and write data in binary mode."),
869 N_("-a --text Treat all files as text."),
871 N_("-c -C NUM --context[=NUM] Output NUM (default 3) lines of copied context.\n\
872 -u -U NUM --unified[=NUM] Output NUM (default 3) lines of unified context.\n\
873 --label LABEL Use LABEL instead of file name.\n\
874 -p --show-c-function Show which C function each change is in.\n\
875 -F RE --show-function-line=RE Show the most recent line matching RE."),
876 N_("-q --brief Output only whether files differ."),
877 N_("-e --ed Output an ed script."),
878 N_("--normal Output a normal diff."),
879 N_("-n --rcs Output an RCS format diff."),
880 N_("-y --side-by-side Output in two columns.\n\
881 -W NUM --width=NUM Output at most NUM (default 130) print columns.\n\
882 --left-column Output only the left column of common lines.\n\
883 --suppress-common-lines Do not output common lines."),
884 N_("-D NAME --ifdef=NAME Output merged file to show `#ifdef NAME' diffs."),
885 N_("--GTYPE-group-format=GFMT Similar, but format GTYPE input groups with GFMT."),
886 N_("--line-format=LFMT Similar, but format all input lines with LFMT."),
887 N_("--LTYPE-line-format=LFMT Similar, but format LTYPE input lines with LFMT."),
888 N_(" LTYPE is `old', `new', or `unchanged'. GTYPE is LTYPE or `changed'."),
889 N_(" GFMT may contain:\n\
890 %< lines from FILE1\n\
891 %> lines from FILE2\n\
892 %= lines common to FILE1 and FILE2\n\
893 %[-][WIDTH][.[PREC]]{doxX}LETTER printf-style spec for LETTER\n\
894 LETTERs are as follows for new group, lower case for old group:\n\
895 F first line number\n\
896 L last line number\n\
897 N number of lines = L-F+1\n\
900 N_(" LFMT may contain:\n\
901 %L contents of line\n\
902 %l contents of line, excluding any trailing newline\n\
903 %[-][WIDTH][.[PREC]]{doxX}n printf-style spec for input line number"),
904 N_(" Either GFMT or LFMT may contain:\n\
906 %c'C' the single character C\n\
907 %c'\\OOO' the character with octal code OOO"),
909 N_("-l --paginate Pass the output through `pr' to paginate it."),
910 N_("-t --expand-tabs Expand tabs to spaces in output."),
911 N_("-T --initial-tab Make tabs line up by prepending a tab."),
912 N_("--tabsize=NUM Tab stops are every NUM (default 8) print columns."),
914 N_("-r --recursive Recursively compare any subdirectories found."),
915 N_("-N --new-file Treat absent files as empty."),
916 N_("--unidirectional-new-file Treat absent first files as empty."),
917 N_("-s --report-identical-files Report when two files are the same."),
918 N_("-x PAT --exclude=PAT Exclude files that match PAT."),
919 N_("-X FILE --exclude-from=FILE Exclude files that match any pattern in FILE."),
920 N_("-S FILE --starting-file=FILE Start with FILE when comparing directories."),
921 N_("--from-file=FILE1 Compare FILE1 to all operands. FILE1 can be a directory."),
922 N_("--to-file=FILE2 Compare all operands to FILE2. FILE2 can be a directory."),
924 N_("--horizon-lines=NUM Keep NUM lines of the common prefix and suffix."),
925 N_("-d --minimal Try hard to find a smaller set of changes."),
926 N_("--speed-large-files Assume large files and many scattered small changes."),
928 N_("-v --version Output version info."),
929 N_("--help Output this help."),
931 N_("FILES are `FILE1 FILE2' or `DIR1 DIR2' or `DIR FILE...' or `FILE... DIR'."),
932 N_("If --from-file or --to-file is given, there are no restrictions on FILES."),
933 N_("If a FILE is `-', read standard input."),
934 N_("Exit status is 0 if inputs are the same, 1 if different, 2 if trouble."),
936 N_("Report bugs to <bug-gnu-utils@gnu.org>."),
943 char const * const *p;
945 printf (_("Usage: %s [OPTION]... FILES\n"), program_name);
947 for (p = option_help_msgid; *p; p++)
953 char const *msg = _(*p);
955 while ((nl = strchr (msg, '\n')))
957 int msglen = nl + 1 - msg;
958 printf (" %.*s", msglen, msg);
962 printf (" %s\n" + 2 * (*msg != ' ' && *msg != '-'), msg);
967 /* Set VAR to VALUE, reporting an OPTION error if this is a
970 specify_value (char const **var, char const *value, char const *option)
972 if (*var && strcmp (*var, value) != 0)
974 error (0, 0, _("conflicting %s option value `%s'"), option, value);
980 /* Set the output style to STYLE, diagnosing conflicts. */
982 specify_style (enum output_style style)
984 if (output_style != style)
986 if (output_style != OUTPUT_UNSPECIFIED)
987 try_help ("conflicting output style options", 0);
988 output_style = style;
992 /* Set the last-modified time of *ST to be the current time. */
995 set_mtime_to_now (struct stat *st)
999 # if HAVE_CLOCK_GETTIME && defined CLOCK_REALTIME
1000 if (clock_gettime (CLOCK_REALTIME, &st->st_mtim) == 0)
1004 # if HAVE_GETTIMEOFDAY
1006 struct timeval timeval;
1007 if (gettimeofday (&timeval, 0) == 0)
1009 st->st_mtime = timeval.tv_sec;
1010 st->st_mtim.ST_MTIM_NSEC = timeval.tv_usec * 1000;
1016 #endif /* ST_MTIM_NSEC */
1018 time (&st->st_mtime);
1021 /* Compare two files (or dirs) with parent comparison PARENT
1022 and names NAME0 and NAME1.
1023 (If PARENT is 0, then the first name is just NAME0, etc.)
1024 This is self-contained; it opens the files and closes them.
1026 Value is EXIT_SUCCESS if files are the same, EXIT_FAILURE if
1027 different, EXIT_TROUBLE if there is a problem opening them. */
1030 compare_files (struct comparison const *parent,
1034 struct comparison cmp;
1035 #define DIR_P(f) (S_ISDIR (cmp.file[f].stat.st_mode) != 0)
1037 int status = EXIT_SUCCESS;
1039 char *free0, *free1;
1041 /* If this is directory comparison, perhaps we have a file
1042 that exists only in one of the directories.
1043 If so, just print a message to that effect. */
1045 if (! ((name0 && name1)
1046 || (unidirectional_new_file && name1)
1049 char const *name = name0 == 0 ? name1 : name0;
1050 char const *dir = parent->file[name0 == 0].name;
1052 /* See POSIX 1003.1-2001 for this format. */
1053 message ("Only in %s: %s\n", dir, name);
1055 /* Return EXIT_FAILURE so that diff_dirs will return
1056 EXIT_FAILURE ("some files differ"). */
1057 return EXIT_FAILURE;
1060 memset (cmp.file, 0, sizeof cmp.file);
1061 cmp.parent = parent;
1063 /* cmp.file[f].desc markers */
1064 #define NONEXISTENT (-1) /* nonexistent file */
1065 #define UNOPENED (-2) /* unopened file (e.g. directory) */
1066 #define ERRNO_ENCODE(errno) (-3 - (errno)) /* encoded errno value */
1068 #define ERRNO_DECODE(desc) (-3 - (desc)) /* inverse of ERRNO_ENCODE */
1070 cmp.file[0].desc = name0 == 0 ? NONEXISTENT : UNOPENED;
1071 cmp.file[1].desc = name1 == 0 ? NONEXISTENT : UNOPENED;
1073 /* Now record the full name of each file, including nonexistent ones. */
1084 cmp.file[0].name = name0;
1085 cmp.file[1].name = name1;
1089 cmp.file[0].name = free0
1090 = dir_file_pathname (parent->file[0].name, name0);
1091 cmp.file[1].name = free1
1092 = dir_file_pathname (parent->file[1].name, name1);
1095 /* Stat the files. */
1097 for (f = 0; f < 2; f++)
1099 if (cmp.file[f].desc != NONEXISTENT)
1101 if (f && file_name_cmp (cmp.file[f].name, cmp.file[0].name) == 0)
1103 cmp.file[f].desc = cmp.file[0].desc;
1104 cmp.file[f].stat = cmp.file[0].stat;
1106 else if (strcmp (cmp.file[f].name, "-") == 0)
1108 cmp.file[f].desc = STDIN_FILENO;
1109 if (fstat (STDIN_FILENO, &cmp.file[f].stat) != 0)
1110 cmp.file[f].desc = ERRNO_ENCODE (errno);
1113 if (S_ISREG (cmp.file[f].stat.st_mode))
1115 off_t pos = lseek (STDIN_FILENO, (off_t) 0, SEEK_CUR);
1117 cmp.file[f].desc = ERRNO_ENCODE (errno);
1119 cmp.file[f].stat.st_size =
1120 MAX (0, cmp.file[f].stat.st_size - pos);
1123 /* POSIX 1003.1-2001 requires current time for
1125 set_mtime_to_now (&cmp.file[f].stat);
1128 else if (stat (cmp.file[f].name, &cmp.file[f].stat) != 0)
1129 cmp.file[f].desc = ERRNO_ENCODE (errno);
1133 /* Mark files as nonexistent as needed for -N and -P, if they are
1134 inaccessible empty regular files (the kind of files that 'patch'
1135 creates to indicate nonexistent backups), or if they are
1136 top-level files that do not exist but their counterparts do
1138 for (f = 0; f < 2; f++)
1139 if ((new_file || (f == 0 && unidirectional_new_file))
1140 && (cmp.file[f].desc == UNOPENED
1141 ? (S_ISREG (cmp.file[f].stat.st_mode)
1142 && ! (cmp.file[f].stat.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO))
1143 && cmp.file[f].stat.st_size == 0)
1144 : (cmp.file[f].desc == ERRNO_ENCODE (ENOENT)
1146 && cmp.file[1 - f].desc == UNOPENED)))
1147 cmp.file[f].desc = NONEXISTENT;
1149 for (f = 0; f < 2; f++)
1150 if (cmp.file[f].desc == NONEXISTENT)
1152 memset (&cmp.file[f].stat, 0, sizeof cmp.file[f].stat);
1153 cmp.file[f].stat.st_mode = cmp.file[1 - f].stat.st_mode;
1156 for (f = 0; f < 2; f++)
1158 int e = ERRNO_DECODE (cmp.file[f].desc);
1162 perror_with_name (cmp.file[f].name);
1163 status = EXIT_TROUBLE;
1167 if (status == EXIT_SUCCESS && ! parent && DIR_P (0) != DIR_P (1))
1169 /* If one is a directory, and it was specified in the command line,
1170 use the file in that dir with the other file's basename. */
1172 int fnm_arg = DIR_P (0);
1173 int dir_arg = 1 - fnm_arg;
1174 char const *fnm = cmp.file[fnm_arg].name;
1175 char const *dir = cmp.file[dir_arg].name;
1176 char const *filename = cmp.file[dir_arg].name = free0
1177 = dir_file_pathname (dir, base_name (fnm));
1179 if (strcmp (fnm, "-") == 0)
1180 fatal ("cannot compare `-' to a directory");
1182 if (stat (filename, &cmp.file[dir_arg].stat) != 0)
1184 perror_with_name (filename);
1185 status = EXIT_TROUBLE;
1189 if (status != EXIT_SUCCESS)
1191 /* One of the files should exist but does not. */
1193 else if (cmp.file[0].desc == NONEXISTENT
1194 && cmp.file[1].desc == NONEXISTENT)
1196 /* Neither file "exists", so there's nothing to compare. */
1198 else if ((same_files
1199 = (cmp.file[0].desc != NONEXISTENT
1200 && cmp.file[1].desc != NONEXISTENT
1201 && 0 < same_file (&cmp.file[0].stat, &cmp.file[1].stat)
1202 && same_file_attributes (&cmp.file[0].stat,
1203 &cmp.file[1].stat)))
1204 && no_diff_means_no_output)
1206 /* The two named files are actually the same physical file.
1207 We know they are identical without actually reading them. */
1209 else if (DIR_P (0) & DIR_P (1))
1211 if (output_style == OUTPUT_IFDEF)
1212 fatal ("-D option not supported with directories");
1214 /* If both are directories, compare the files in them. */
1216 if (parent && !recursive)
1218 /* But don't compare dir contents one level down
1219 unless -r was specified.
1220 See POSIX 1003.1-2001 for this format. */
1221 message ("Common subdirectories: %s and %s\n",
1222 cmp.file[0].name, cmp.file[1].name);
1225 status = diff_dirs (&cmp, compare_files);
1227 else if ((DIR_P (0) | DIR_P (1))
1229 && (! S_ISREG (cmp.file[0].stat.st_mode)
1230 || ! S_ISREG (cmp.file[1].stat.st_mode))))
1232 if (cmp.file[0].desc == NONEXISTENT || cmp.file[1].desc == NONEXISTENT)
1234 /* We have a subdirectory that exists only in one directory. */
1236 if ((DIR_P (0) | DIR_P (1))
1239 || (unidirectional_new_file
1240 && cmp.file[0].desc == NONEXISTENT)))
1241 status = diff_dirs (&cmp, compare_files);
1245 = parent->file[cmp.file[0].desc == NONEXISTENT].name;
1247 /* See POSIX 1003.1-2001 for this format. */
1248 message ("Only in %s: %s\n", dir, name0);
1250 status = EXIT_FAILURE;
1255 /* We have two files that are not to be compared. */
1257 /* See POSIX 1003.1-2001 for this format. */
1258 message5 ("File %s is a %s while file %s is a %s\n",
1259 file_label[0] ? file_label[0] : cmp.file[0].name,
1260 file_type (&cmp.file[0].stat),
1261 file_label[1] ? file_label[1] : cmp.file[1].name,
1262 file_type (&cmp.file[1].stat));
1264 /* This is a difference. */
1265 status = EXIT_FAILURE;
1268 else if (files_can_be_treated_as_binary
1269 && S_ISREG (cmp.file[0].stat.st_mode)
1270 && S_ISREG (cmp.file[1].stat.st_mode)
1271 && cmp.file[0].stat.st_size != cmp.file[1].stat.st_size)
1273 message ("Files %s and %s differ\n",
1274 file_label[0] ? file_label[0] : cmp.file[0].name,
1275 file_label[1] ? file_label[1] : cmp.file[1].name);
1276 status = EXIT_FAILURE;
1280 /* Both exist and neither is a directory. */
1282 /* Open the files and record their descriptors. */
1284 if (cmp.file[0].desc == UNOPENED)
1285 if ((cmp.file[0].desc = open (cmp.file[0].name, O_RDONLY, 0)) < 0)
1287 perror_with_name (cmp.file[0].name);
1288 status = EXIT_TROUBLE;
1290 if (cmp.file[1].desc == UNOPENED)
1293 cmp.file[1].desc = cmp.file[0].desc;
1294 else if ((cmp.file[1].desc = open (cmp.file[1].name, O_RDONLY, 0))
1297 perror_with_name (cmp.file[1].name);
1298 status = EXIT_TROUBLE;
1302 #if HAVE_SETMODE_DOS
1304 for (f = 0; f < 2; f++)
1305 if (0 <= cmp.file[f].desc)
1306 set_binary_mode (cmp.file[f].desc, true);
1309 /* Compare the files, if no error was found. */
1311 if (status == EXIT_SUCCESS)
1312 status = diff_2_files (&cmp);
1314 /* Close the file descriptors. */
1316 if (0 <= cmp.file[0].desc && close (cmp.file[0].desc) != 0)
1318 perror_with_name (cmp.file[0].name);
1319 status = EXIT_TROUBLE;
1321 if (0 <= cmp.file[1].desc && cmp.file[0].desc != cmp.file[1].desc
1322 && close (cmp.file[1].desc) != 0)
1324 perror_with_name (cmp.file[1].name);
1325 status = EXIT_TROUBLE;
1329 /* Now the comparison has been done, if no error prevented it,
1330 and STATUS is the value this function will return. */
1332 if (status == EXIT_SUCCESS)
1334 if (report_identical_files && !DIR_P (0))
1335 message ("Files %s and %s are identical\n",
1336 file_label[0] ? file_label[0] : cmp.file[0].name,
1337 file_label[1] ? file_label[1] : cmp.file[1].name);
1341 /* Flush stdout so that the user sees differences immediately.
1342 This can hurt performance, unfortunately. */
1343 if (fflush (stdout) != 0)
1344 pfatal_with_name (_("standard output"));