-/* GNU DIFF main routine.

- Copyright (C) 1988, 1989, 1992, 1993, 1994 Free Software Foundation, Inc.

-

-This file is part of GNU DIFF.

-

-GNU DIFF is free software; you can redistribute it and/or modify

-it under the terms of the GNU General Public License as published by

-the Free Software Foundation; either version 2, or (at your option)

-any later version.

-

-GNU DIFF is distributed in the hope that it will be useful,

-but WITHOUT ANY WARRANTY; without even the implied warranty of

-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

-GNU General Public License for more details.

-

-You should have received a copy of the GNU General Public License

-along with GNU DIFF; see the file COPYING. If not, write to

-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */

-

-/* GNU DIFF was written by Mike Haertel, David Hayes,

- Richard Stallman, Len Tower, and Paul Eggert. */

-

-/* $FreeBSD$ */

-

-#define GDIFF_MAIN

-#include "diff.h"

-#include <signal.h>

-#include "getopt.h"

-#ifdef __FreeBSD__

-#include <locale.h>

-#include <fnmatch.h>

-#else

-#include "fnmatch.h"

-#endif

-#include "prepend_args.h"

-

-#ifndef DEFAULT_WIDTH

-#define DEFAULT_WIDTH 130

-#endif

-

-#ifndef GUTTER_WIDTH_MINIMUM

-#define GUTTER_WIDTH_MINIMUM 3

-#endif

-

-static char const *filetype PARAMS((struct stat const *));

-static char *option_list PARAMS((char **, int));

-static int add_exclude_file PARAMS((char const *));

-static int ck_atoi PARAMS((char const *, int *));

-static int compare_files PARAMS((char const *, char const *, char const *, char const *, int));

-static int specify_format PARAMS((char **, char *));

-static void add_exclude PARAMS((char const *));

-static void add_regexp PARAMS((struct regexp_list **, char const *));

-static void specify_style PARAMS((enum output_style));

-static void try_help PARAMS((char const *));

-static void check_stdout PARAMS((void));

-static void usage PARAMS((void));

-

-/* Nonzero for -r: if comparing two directories,

- compare their common subdirectories recursively. */

-

-static int recursive;

-

-/* For debugging: don't do discard_confusing_lines. */

-

-int no_discards;

-

-#if HAVE_SETMODE

-/* I/O mode: nonzero only if using binary input/output. */

-static int binary_I_O;

-#endif

-

-/* Return a string containing the command options with which diff was invoked.

- Spaces appear between what were separate ARGV-elements.

- There is a space at the beginning but none at the end.

- If there were no options, the result is an empty string.

-

- Arguments: OPTIONVEC, a vector containing separate ARGV-elements, and COUNT,

- the length of that vector. */

-

-static char *

-option_list (optionvec, count)

- char **optionvec; /* Was `vector', but that collides on Alliant. */

- int count;

-{

- int i;

- size_t length = 0;

- char *result;

-

- for (i = 0; i < count; i++)

- length += strlen (optionvec[i]) + 1;

-

- result = xmalloc (length + 1);

- result[0] = 0;

-

- for (i = 0; i < count; i++)

- {

- strcat (result, " ");

- strcat (result, optionvec[i]);

- }

-

- return result;

-}

-

-/* Convert STR to a positive integer, storing the result in *OUT.

- If STR is not a valid integer, return -1 (otherwise 0). */

-static int

-ck_atoi (str, out)

- char const *str;

- int *out;

-{

- char const *p;

- for (p = str; *p; p++)

- if (*p < '0' || *p > '9')

- return -1;

-

- *out = atoi (optarg);

- return 0;

-}

-

-/* Keep track of excluded file name patterns. */

-

-static char const **exclude;

-static int exclude_alloc, exclude_count;

-

-int

-excluded_filename (f)

- char const *f;

-{

- int i;

- for (i = 0; i < exclude_count; i++)

- if (fnmatch (exclude[i], f, 0) == 0)

- return 1;

- return 0;

-}

-

-static void

-add_exclude (pattern)

- char const *pattern;

-{

- if (exclude_alloc <= exclude_count)

- exclude = (char const **)

- (exclude_alloc == 0

- ? xmalloc ((exclude_alloc = 64) * sizeof (*exclude))

- : xrealloc (exclude, (exclude_alloc *= 2) * sizeof (*exclude)));

-

- exclude[exclude_count++] = pattern;

-}

-

-static int

-add_exclude_file (name)

- char const *name;

-{

- struct file_data f;

- char *p, *q, *lim;

-

- f.name = optarg;

- f.desc = (strcmp (optarg, "-") == 0

- ? STDIN_FILENO

- : open (optarg, O_RDONLY, 0));

- if (f.desc < 0 || fstat (f.desc, &f.stat) != 0)

- return -1;

-

- sip (&f, 1);

- slurp (&f);

-

- for (p = f.buffer, lim = p + f.buffered_chars; p < lim; p = q)

- {

- q = (char *) memchr (p, '\n', lim - p);

- if (!q)

- q = lim;

- *q++ = 0;

- add_exclude (p);

- }

-

- return close (f.desc);

-}

-

-/* The numbers 129- that appear in the fourth element of some entries

- tell the big switch in `main' how to process those options. */

-

-static struct option const longopts[] =

-{

- {"ignore-blank-lines", 0, 0, 'B'},

- {"context", 2, 0, 'C'},

- {"ifdef", 1, 0, 'D'},

- {"show-function-line", 1, 0, 'F'},

- {"speed-large-files", 0, 0, 'H'},

- {"ignore-matching-lines", 1, 0, 'I'},

- {"label", 1, 0, 'L'},

- {"file-label", 1, 0, 'L'}, /* An alias, no longer recommended */

- {"new-file", 0, 0, 'N'},

- {"entire-new-file", 0, 0, 'N'}, /* An alias, no longer recommended */

- {"unidirectional-new-file", 0, 0, 'P'},

- {"starting-file", 1, 0, 'S'},

- {"initial-tab", 0, 0, 'T'},

- {"width", 1, 0, 'W'},

- {"text", 0, 0, 'a'},

- {"ascii", 0, 0, 'a'}, /* An alias, no longer recommended */

- {"ignore-space-change", 0, 0, 'b'},

- {"minimal", 0, 0, 'd'},

- {"ed", 0, 0, 'e'},

- {"forward-ed", 0, 0, 'f'},

- {"ignore-case", 0, 0, 'i'},

- {"paginate", 0, 0, 'l'},

- {"print", 0, 0, 'l'}, /* An alias, no longer recommended */

- {"rcs", 0, 0, 'n'},

- {"show-c-function", 0, 0, 'p'},

- {"brief", 0, 0, 'q'},

- {"recursive", 0, 0, 'r'},

- {"report-identical-files", 0, 0, 's'},

- {"expand-tabs", 0, 0, 't'},

- {"version", 0, 0, 'v'},

- {"ignore-all-space", 0, 0, 'w'},

- {"exclude", 1, 0, 'x'},

- {"exclude-from", 1, 0, 'X'},

- {"side-by-side", 0, 0, 'y'},

- {"unified", 2, 0, 'U'},

- {"left-column", 0, 0, 129},

- {"suppress-common-lines", 0, 0, 130},

- {"sdiff-merge-assist", 0, 0, 131},

- {"old-line-format", 1, 0, 132},

- {"new-line-format", 1, 0, 133},

- {"unchanged-line-format", 1, 0, 134},

- {"line-format", 1, 0, 135},

- {"old-group-format", 1, 0, 136},

- {"new-group-format", 1, 0, 137},

- {"unchanged-group-format", 1, 0, 138},

- {"changed-group-format", 1, 0, 139},

- {"horizon-lines", 1, 0, 140},

- {"help", 0, 0, 141},

- {"binary", 0, 0, 142},

- {0, 0, 0, 0}

-};

-

-int

-main (argc, argv)

- int argc;

- char *argv[];

-{

- int val;

- int c;

- int prev = -1;

- int width = DEFAULT_WIDTH;

- int show_c_function = 0;

-

-#ifdef __FreeBSD__

- setlocale(LC_ALL, "");

-#endif

- /* Do our initializations. */

- initialize_main (&argc, &argv);

- program_name = argv[0];

- output_style = OUTPUT_NORMAL;

- context = -1;

-

- prepend_default_options (getenv ("DIFF_OPTIONS"), &argc, &argv);

-

- /* Decode the options. */

-

- while ((c = getopt_long (argc, argv,

- "0123456789abBcC:dD:efF:hHiI:lL:nNopPqrsS:tTuU:vwW:x:X:y",

- longopts, 0)) != EOF)

- {

- switch (c)

- {

- /* All digits combine in decimal to specify the context-size. */

- case '1':

- case '2':

- case '3':

- case '4':

- case '5':

- case '6':

- case '7':

- case '8':

- case '9':

- case '0':

- if (context == -1)

- context = 0;

- /* If a context length has already been specified,

- more digits allowed only if they follow right after the others.

- Reject two separate runs of digits, or digits after -C. */

- else if (prev < '0' || prev > '9')

- fatal ("context length specified twice");

-

- context = context * 10 + c - '0';

- break;

-

- case 'a':

- /* Treat all files as text files; never treat as binary. */

- always_text_flag = 1;

- break;

-

- case 'b':

- /* Ignore changes in amount of white space. */

- ignore_space_change_flag = 1;

- ignore_some_changes = 1;

- ignore_some_line_changes = 1;

- break;

-

- case 'B':

- /* Ignore changes affecting only blank lines. */

- ignore_blank_lines_flag = 1;

- ignore_some_changes = 1;

- break;

-

- case 'C': /* +context[=lines] */

- case 'U': /* +unified[=lines] */

- if (optarg)

- {

- if (context >= 0)

- fatal ("context length specified twice");

-

- if (ck_atoi (optarg, &context))

- fatal ("invalid context length argument");

- }

-

- /* Falls through. */

- case 'c':

- /* Make context-style output. */

- specify_style (c == 'U' ? OUTPUT_UNIFIED : OUTPUT_CONTEXT);

- break;

-

- case 'd':

- /* Don't discard lines. This makes things slower (sometimes much

- slower) but will find a guaranteed minimal set of changes. */

- no_discards = 1;

- break;

-

- case 'D':

- /* Make merged #ifdef output. */

- specify_style (OUTPUT_IFDEF);

- {

- int i, err = 0;

- static char const C_ifdef_group_formats[] =

- "#ifndef %s\n%%<#endif /* not %s */\n%c#ifdef %s\n%%>#endif /* %s */\n%c%%=%c#ifndef %s\n%%<#else /* %s */\n%%>#endif /* %s */\n";

- char *b = xmalloc (sizeof (C_ifdef_group_formats)

- + 7 * strlen(optarg) - 14 /* 7*"%s" */

- - 8 /* 5*"%%" + 3*"%c" */);

- sprintf (b, C_ifdef_group_formats,

- optarg, optarg, 0,

- optarg, optarg, 0, 0,

- optarg, optarg, optarg);

- for (i = 0; i < 4; i++)

- {

- err |= specify_format (&group_format[i], b);

- b += strlen (b) + 1;

- }

- if (err)

- error ("conflicting #ifdef formats", 0, 0);

- }

- break;

-

- case 'e':

- /* Make output that is a valid `ed' script. */

- specify_style (OUTPUT_ED);

- break;

-

- case 'f':

- /* Make output that looks vaguely like an `ed' script

- but has changes in the order they appear in the file. */

- specify_style (OUTPUT_FORWARD_ED);

- break;

-

- case 'F':

- /* Show, for each set of changes, the previous line that

- matches the specified regexp. Currently affects only

- context-style output. */

- add_regexp (&function_regexp_list, optarg);

- break;

-

- case 'h':

- /* Split the files into chunks of around 1500 lines

- for faster processing. Usually does not change the result.

-

- This currently has no effect. */

- break;

-

- case 'H':

- /* Turn on heuristics that speed processing of large files

- with a small density of changes. */

- heuristic = 1;

- break;

-

- case 'i':

- /* Ignore changes in case. */

- ignore_case_flag = 1;

- ignore_some_changes = 1;

- ignore_some_line_changes = 1;

- break;

-

- case 'I':

- /* Ignore changes affecting only lines that match the

- specified regexp. */

- add_regexp (&ignore_regexp_list, optarg);

- ignore_some_changes = 1;

- break;

-

- case 'l':

- /* Pass the output through `pr' to paginate it. */

- paginate_flag = 1;

-#if !defined(SIGCHLD) && defined(SIGCLD)

-#define SIGCHLD SIGCLD

-#endif

-#ifdef SIGCHLD

- /* Pagination requires forking and waiting, and

- System V fork+wait does not work if SIGCHLD is ignored. */

- signal (SIGCHLD, SIG_DFL);

-#endif

- break;

-

- case 'L':

- /* Specify file labels for `-c' output headers. */

- if (!file_label[0])

- file_label[0] = optarg;

- else if (!file_label[1])

- file_label[1] = optarg;

- else

- fatal ("too many file label options");

- break;

-

- case 'n':

- /* Output RCS-style diffs, like `-f' except that each command

- specifies the number of lines affected. */

- specify_style (OUTPUT_RCS);

- break;

-

- case 'N':

- /* When comparing directories, if a file appears only in one

- directory, treat it as present but empty in the other. */

- entire_new_file_flag = 1;

- break;

-

- case 'o':

- /* Output in the old tradition style. */

- specify_style (OUTPUT_NORMAL);

- break;

-

- case 'p':

- /* Make context-style output and show name of last C function. */

- show_c_function = 1;

- add_regexp (&function_regexp_list, "^[_a-zA-Z$]");

- break;

-

- case 'P':

- /* When comparing directories, if a file appears only in

- the second directory of the two,

- treat it as present but empty in the other. */

- unidirectional_new_file_flag = 1;

- break;

-

- case 'q':

- no_details_flag = 1;

- break;

-

- case 'r':

- /* When comparing directories,

- recursively compare any subdirectories found. */

- recursive = 1;

- break;

-

- case 's':

- /* Print a message if the files are the same. */

- print_file_same_flag = 1;

- break;

-

- case 'S':

- /* When comparing directories, start with the specified

- file name. This is used for resuming an aborted comparison. */

- dir_start_file = optarg;

- break;

-

- case 't':

- /* Expand tabs to spaces in the output so that it preserves

- the alignment of the input files. */

- tab_expand_flag = 1;

- break;

-

- case 'T':

- /* Use a tab in the output, rather than a space, before the

- text of an input line, so as to keep the proper alignment

- in the input line without changing the characters in it. */

- tab_align_flag = 1;

- break;

-

- case 'u':

- /* Output the context diff in unidiff format. */

- specify_style (OUTPUT_UNIFIED);

- break;

-

- case 'v':

- printf ("diff - GNU diffutils version %s\n", version_string);

- exit (0);

-

- case 'w':

- /* Ignore horizontal white space when comparing lines. */

- ignore_all_space_flag = 1;

- ignore_some_changes = 1;

- ignore_some_line_changes = 1;

- break;

-

- case 'x':

- add_exclude (optarg);

- break;

-

- case 'X':

- if (add_exclude_file (optarg) != 0)

- pfatal_with_name (optarg);

- break;

-

- case 'y':

- /* Use side-by-side (sdiff-style) columnar output. */

- specify_style (OUTPUT_SDIFF);

- break;

-

- case 'W':

- /* Set the line width for OUTPUT_SDIFF. */

- if (ck_atoi (optarg, &width) || width <= 0)

- fatal ("column width must be a positive integer");

- break;

-

- case 129:

- sdiff_left_only = 1;

- break;

-

- case 130:

- sdiff_skip_common_lines = 1;

- break;

-

- case 131:

- /* sdiff-style columns output. */

- specify_style (OUTPUT_SDIFF);

- sdiff_help_sdiff = 1;

- break;

-

- case 132:

- case 133:

- case 134:

- specify_style (OUTPUT_IFDEF);

- if (specify_format (&line_format[c - 132], optarg) != 0)

- error ("conflicting line format", 0, 0);

- break;

-

- case 135:

- specify_style (OUTPUT_IFDEF);

- {

- int i, err = 0;

- for (i = 0; i < sizeof (line_format) / sizeof (*line_format); i++)

- err |= specify_format (&line_format[i], optarg);

- if (err)

- error ("conflicting line format", 0, 0);

- }

- break;

-

- case 136:

- case 137:

- case 138:

- case 139:

- specify_style (OUTPUT_IFDEF);

- if (specify_format (&group_format[c - 136], optarg) != 0)

- error ("conflicting group format", 0, 0);

- break;

-

- case 140:

- if (ck_atoi (optarg, &horizon_lines) || horizon_lines < 0)

- fatal ("horizon must be a nonnegative integer");

- break;

-

- case 141:

- usage ();

- check_stdout ();

- exit (0);

-

- case 142:

- /* Use binary I/O when reading and writing data.

- On Posix hosts, this has no effect. */

-#if HAVE_SETMODE

- binary_I_O = 1;

- setmode (STDOUT_FILENO, O_BINARY);

-#endif

- break;

-

- default:

- try_help (0);

- }

- prev = c;

- }

-

- if (argc - optind != 2)

- try_help (argc - optind < 2 ? "missing operand" : "extra operand");

-

-

- {

- /*

- * We maximize first the half line width, and then the gutter width,

- * according to the following constraints:

- * 1. Two half lines plus a gutter must fit in a line.

- * 2. If the half line width is nonzero:

- * a. The gutter width is at least GUTTER_WIDTH_MINIMUM.

- * b. If tabs are not expanded to spaces,

- * a half line plus a gutter is an integral number of tabs,

- * so that tabs in the right column line up.

- */

- int t = tab_expand_flag ? 1 : TAB_WIDTH;

- int off = (width + t + GUTTER_WIDTH_MINIMUM) / (2*t) * t;

- sdiff_half_width = max (0, min (off - GUTTER_WIDTH_MINIMUM, width - off)),

- sdiff_column2_offset = sdiff_half_width ? off : width;

- }

-

- if (show_c_function && output_style != OUTPUT_UNIFIED)

- specify_style (OUTPUT_CONTEXT);

-

- if (output_style != OUTPUT_CONTEXT && output_style != OUTPUT_UNIFIED)

- context = 0;

- else if (context == -1)

- /* Default amount of context for -c. */

- context = 3;

-

- if (output_style == OUTPUT_IFDEF)

- {

- /* Format arrays are char *, not char const *,

- because integer formats are temporarily modified.

- But it is safe to assign a constant like "%=" to a format array,

- since "%=" does not format any integers. */

- int i;

- for (i = 0; i < sizeof (line_format) / sizeof (*line_format); i++)

- if (!line_format[i])

- line_format[i] = "%l\n";

- if (!group_format[OLD])

- group_format[OLD]

- = group_format[UNCHANGED] ? group_format[UNCHANGED] : "%<";

- if (!group_format[NEW])

- group_format[NEW]

- = group_format[UNCHANGED] ? group_format[UNCHANGED] : "%>";

- if (!group_format[UNCHANGED])

- group_format[UNCHANGED] = "%=";

- if (!group_format[CHANGED])

- group_format[CHANGED] = concat (group_format[OLD],

- group_format[NEW], "");

- }

-

- no_diff_means_no_output =

- (output_style == OUTPUT_IFDEF ?

- (!*group_format[UNCHANGED]

- || (strcmp (group_format[UNCHANGED], "%=") == 0

- && !*line_format[UNCHANGED]))

- : output_style == OUTPUT_SDIFF ? sdiff_skip_common_lines : 1);

-

- switch_string = option_list (argv + 1, optind - 1);

-

- val = compare_files (0, argv[optind], 0, argv[optind + 1], 0);

-

- /* Print any messages that were saved up for last. */

- print_message_queue ();

-

- check_stdout ();

- exit (val);

- return val;

-}

-

-/* Add the compiled form of regexp PATTERN to REGLIST. */

-

-static void

-add_regexp (reglist, pattern)

- struct regexp_list **reglist;

- char const *pattern;

-{

- struct regexp_list *r;

- char const *m;

-

- r = (struct regexp_list *) xmalloc (sizeof (*r));

- bzero (r, sizeof (*r));

- r->buf.fastmap = xmalloc (256);

- m = re_compile_pattern (pattern, strlen (pattern), &r->buf);

- if (m != 0)

- error ("%s: %s", pattern, m);

-

- /* Add to the start of the list, since it's easier than the end. */

- r->next = *reglist;

- *reglist = r;

-}

-

-static void

-try_help (reason)

- char const *reason;

-{

- if (reason)

- error ("%s", reason, 0);

- error ("Try `%s --help' for more information.", program_name, 0);

- exit (2);

-}

-

-static void

-check_stdout ()

-{

- if (ferror (stdout) || fclose (stdout) != 0)

- fatal ("write error");

-}

-

-static char const * const option_help[] = {

-"-i --ignore-case Consider upper- and lower-case to be the same.",

-"-w --ignore-all-space Ignore all white space.",

-"-b --ignore-space-change Ignore changes in the amount of white space.",

-"-B --ignore-blank-lines Ignore changes whose lines are all blank.",

-"-I RE --ignore-matching-lines=RE Ignore changes whose lines all match RE.",

-#if HAVE_SETMODE

-"--binary Read and write data in binary mode.",

-#endif

-"-a --text Treat all files as text.\n",

-"-c -C NUM --context[=NUM] Output NUM (default 2) lines of copied context.",

-"-u -U NUM --unified[=NUM] Output NUM (default 2) lines of unified context.",

-" -NUM Use NUM context lines.",

-" -L LABEL --label LABEL Use LABEL instead of file name.",

-" -p --show-c-function Show which C function each change is in.",

-" -F RE --show-function-line=RE Show the most recent line matching RE.",

-"-q --brief Output only whether files differ.",

-"-e --ed Output an ed script.",

-"-n --rcs Output an RCS format diff.",

-"-y --side-by-side Output in two columns.",

-" -W NUM --width=NUM Output at most NUM (default 130) characters per line.",

-" --left-column Output only the left column of common lines.",

-" --suppress-common-lines Do not output common lines.",

-"-DNAME --ifdef=NAME Output merged file to show `#ifdef NAME' diffs.",

-"--GTYPE-group-format=GFMT Similar, but format GTYPE input groups with GFMT.",

-"--line-format=LFMT Similar, but format all input lines with LFMT.",

-"--LTYPE-line-format=LFMT Similar, but format LTYPE input lines with LFMT.",

-" LTYPE is `old', `new', or `unchanged'. GTYPE is LTYPE or `changed'.",

-" GFMT may contain:",

-" %< lines from FILE1",

-" %> lines from FILE2",

-" %= lines common to FILE1 and FILE2",

-" %[-][WIDTH][.[PREC]]{doxX}LETTER printf-style spec for LETTER",

-" LETTERs are as follows for new group, lower case for old group:",

-" F first line number",

-" L last line number",

-" N number of lines = L-F+1",

-" E F-1",

-" M L+1",

-" LFMT may contain:",

-" %L contents of line",

-" %l contents of line, excluding any trailing newline",

-" %[-][WIDTH][.[PREC]]{doxX}n printf-style spec for input line number",

-" Either GFMT or LFMT may contain:",

-" %% %",

-" %c'C' the single character C",

-" %c'\\OOO' the character with octal code OOO\n",

-"-l --paginate Pass the output through `pr' to paginate it.",

-"-t --expand-tabs Expand tabs to spaces in output.",

-"-T --initial-tab Make tabs line up by prepending a tab.\n",

-"-r --recursive Recursively compare any subdirectories found.",

-"-N --new-file Treat absent files as empty.",

-"-P --unidirectional-new-file Treat absent first files as empty.",

-"-s --report-identical-files Report when two files are the same.",

-"-x PAT --exclude=PAT Exclude files that match PAT.",

-"-X FILE --exclude-from=FILE Exclude files that match any pattern in FILE.",

-"-S FILE --starting-file=FILE Start with FILE when comparing directories.\n",

-"--horizon-lines=NUM Keep NUM lines of the common prefix and suffix.",

-"-d --minimal Try hard to find a smaller set of changes.",

-"-H --speed-large-files Assume large files and many scattered small changes.\n",

-"-v --version Output version info.",

-"--help Output this help.",

-0

-};

-

-static void

-usage ()

-{

- char const * const *p;

-

- printf ("Usage: %s [OPTION]... FILE1 FILE2\n\n", program_name);

- for (p = option_help; *p; p++)

- printf (" %s\n", *p);

- printf ("\nIf FILE1 or FILE2 is `-', read standard input.\n");

-}

-

-static int

-specify_format (var, value)

- char **var;

- char *value;

-{

- int err = *var ? strcmp (*var, value) : 0;

- *var = value;

- return err;

-}

-

-static void

-specify_style (style)

- enum output_style style;

-{

- output_style = style;

-}

-

-static char const *

-filetype (st)

- struct stat const *st;

-{

- /* See Posix.2 section 4.17.6.1.1 and Table 5-1 for these formats.

- To keep diagnostics grammatical, the returned string must start

- with a consonant. */

-

- if (S_ISREG (st->st_mode))

- {

- if (st->st_size == 0)

- return "regular empty file";

- /* Posix.2 section 5.14.2 seems to suggest that we must read the file

- and guess whether it's C, Fortran, etc., but this is somewhat useless

- and doesn't reflect historical practice. We're allowed to guess

- wrong, so we don't bother to read the file. */

- return "regular file";

- }

- if (S_ISDIR (st->st_mode)) return "directory";

-

- /* other Posix.1 file types */

-#ifdef S_ISBLK

- if (S_ISBLK (st->st_mode)) return "block special file";

-#endif

-#ifdef S_ISCHR

- if (S_ISCHR (st->st_mode)) return "character special file";

-#endif

-#ifdef S_ISFIFO

- if (S_ISFIFO (st->st_mode)) return "fifo";

-#endif

-

- /* other Posix.1b file types */

-#ifdef S_TYPEISMQ

- if (S_TYPEISMQ (st)) return "message queue";

-#endif

-#ifdef S_TYPEISSEM

- if (S_TYPEISSEM (st)) return "semaphore";

-#endif

-#ifdef S_TYPEISSHM

- if (S_TYPEISSHM (st)) return "shared memory object";

-#endif

-

- /* other popular file types */

- /* S_ISLNK is impossible with `fstat' and `stat'. */

-#ifdef S_ISSOCK

- if (S_ISSOCK (st->st_mode)) return "socket";

-#endif

-

- return "weird file";

-}

-

-/* Compare two files (or dirs) with specified names

- DIR0/NAME0 and DIR1/NAME1, at level DEPTH in directory recursion.

- (if DIR0 is 0, then the name is just NAME0, etc.)

- This is self-contained; it opens the files and closes them.

-

- Value is 0 if files are the same, 1 if different,

- 2 if there is a problem opening them. */

-

-static int

-compare_files (dir0, name0, dir1, name1, depth)

- char const *dir0, *dir1;

- char const *name0, *name1;

- int depth;

-{

- struct file_data inf[2];

- register int i;

- int val;

- int same_files;

- int failed = 0;

- char *free0 = 0, *free1 = 0;

-

- /* If this is directory comparison, perhaps we have a file

- that exists only in one of the directories.

- If so, just print a message to that effect. */

-

- if (! ((name0 != 0 && name1 != 0)

- || (unidirectional_new_file_flag && name1 != 0)

- || entire_new_file_flag))

- {

- char const *name = name0 == 0 ? name1 : name0;

- char const *dir = name0 == 0 ? dir1 : dir0;

- message ("Only in %s: %s\n", dir, name);

- /* Return 1 so that diff_dirs will return 1 ("some files differ"). */

- return 1;

- }

-

- bzero (inf, sizeof (inf));

-

- /* Mark any nonexistent file with -1 in the desc field. */

- /* Mark unopened files (e.g. directories) with -2. */

-

- inf[0].desc = name0 == 0 ? -1 : -2;

- inf[1].desc = name1 == 0 ? -1 : -2;

-

- /* Now record the full name of each file, including nonexistent ones. */

-

- if (name0 == 0)

- name0 = name1;

- if (name1 == 0)

- name1 = name0;

-

- inf[0].name = dir0 == 0 ? name0 : (free0 = dir_file_pathname (dir0, name0));

- inf[1].name = dir1 == 0 ? name1 : (free1 = dir_file_pathname (dir1, name1));

-

- /* Stat the files. Record whether they are directories. */

-

- for (i = 0; i <= 1; i++)

- {

- if (inf[i].desc != -1)

- {

- int stat_result;

-

- if (i && filename_cmp (inf[i].name, inf[0].name) == 0)

- {

- inf[i].stat = inf[0].stat;

- stat_result = 0;

- }

- else if (strcmp (inf[i].name, "-") == 0)

- {

- inf[i].desc = STDIN_FILENO;

- stat_result = fstat (STDIN_FILENO, &inf[i].stat);

- if (stat_result == 0 && S_ISREG (inf[i].stat.st_mode))

- {

- off_t pos = lseek (STDIN_FILENO, (off_t) 0, SEEK_CUR);

- if (pos == -1)

- stat_result = -1;

- else

- {

- if (pos <= inf[i].stat.st_size)

- inf[i].stat.st_size -= pos;

- else

- inf[i].stat.st_size = 0;

- /* Posix.2 4.17.6.1.4 requires current time for stdin. */

- time (&inf[i].stat.st_mtime);

- }

- }

- }

- else

- stat_result = stat (inf[i].name, &inf[i].stat);

-

- if (stat_result != 0)

- {

- perror_with_name (inf[i].name);

- failed = 1;

- }

- else

- {

- inf[i].dir_p = S_ISDIR (inf[i].stat.st_mode) && inf[i].desc != 0;

- if (inf[1 - i].desc == -1)

- {

- inf[1 - i].dir_p = inf[i].dir_p;

- inf[1 - i].stat.st_mode = inf[i].stat.st_mode;

- }

- }

- }

- }

-

- if (! failed && depth == 0 && inf[0].dir_p != inf[1].dir_p)

- {

- /* If one is a directory, and it was specified in the command line,

- use the file in that dir with the other file's basename. */

-

- int fnm_arg = inf[0].dir_p;

- int dir_arg = 1 - fnm_arg;

- char const *fnm = inf[fnm_arg].name;

- char const *dir = inf[dir_arg].name;

- char const *p = filename_lastdirchar (fnm);

- char const *filename = inf[dir_arg].name

- = dir_file_pathname (dir, p ? p + 1 : fnm);

-

- if (strcmp (fnm, "-") == 0)

- fatal ("can't compare - to a directory");

-

- if (stat (filename, &inf[dir_arg].stat) != 0)

- {

- perror_with_name (filename);

- failed = 1;

- }

- else

- inf[dir_arg].dir_p = S_ISDIR (inf[dir_arg].stat.st_mode);

- }

-

- if (failed)

- {

-

- /* If either file should exist but does not, return 2. */

-

- val = 2;

-

- }

- else if ((same_files = inf[0].desc != -1 && inf[1].desc != -1

- && 0 < same_file (&inf[0].stat, &inf[1].stat))

- && no_diff_means_no_output)

- {

- /* The two named files are actually the same physical file.

- We know they are identical without actually reading them. */

-

- val = 0;

- }

- else if (inf[0].dir_p & inf[1].dir_p)

- {

- if (output_style == OUTPUT_IFDEF)

- fatal ("-D option not supported with directories");

-

- /* If both are directories, compare the files in them. */

-

- if (depth > 0 && !recursive)

- {

- /* But don't compare dir contents one level down

- unless -r was specified. */

- message ("Common subdirectories: %s and %s\n",

- inf[0].name, inf[1].name);

- val = 0;

- }

- else

- {

- val = diff_dirs (inf, compare_files, depth);

- }

-

- }

- else if ((inf[0].dir_p | inf[1].dir_p)

- || (depth > 0

- && (! S_ISREG (inf[0].stat.st_mode)

- || ! S_ISREG (inf[1].stat.st_mode))))

- {

- /* Perhaps we have a subdirectory that exists only in one directory.

- If so, just print a message to that effect. */

-

- if (inf[0].desc == -1 || inf[1].desc == -1)

- {

- if ((inf[0].dir_p | inf[1].dir_p)

- && recursive

- && (entire_new_file_flag

- || (unidirectional_new_file_flag && inf[0].desc == -1)))

- val = diff_dirs (inf, compare_files, depth);

- else

- {

- char const *dir = (inf[0].desc == -1) ? dir1 : dir0;

- /* See Posix.2 section 4.17.6.1.1 for this format. */

- message ("Only in %s: %s\n", dir, name0);

- val = 1;

- }

- }

- else

- {

- /* We have two files that are not to be compared. */

-

- /* See Posix.2 section 4.17.6.1.1 for this format. */

- message5 ("File %s is a %s while file %s is a %s\n",

- inf[0].name, filetype (&inf[0].stat),

- inf[1].name, filetype (&inf[1].stat));

-

- /* This is a difference. */

- val = 1;

- }

- }

- else if ((no_details_flag & ~ignore_some_changes)

- && inf[0].stat.st_size != inf[1].stat.st_size

- && (inf[0].desc == -1 || S_ISREG (inf[0].stat.st_mode))

- && (inf[1].desc == -1 || S_ISREG (inf[1].stat.st_mode)))

- {

- message ("Files %s and %s differ\n", inf[0].name, inf[1].name);

- val = 1;

- }

- else

- {

- /* Both exist and neither is a directory. */

-

- /* Open the files and record their descriptors. */

-

- if (inf[0].desc == -2)

- if ((inf[0].desc = open (inf[0].name, O_RDONLY, 0)) < 0)

- {

- perror_with_name (inf[0].name);

- failed = 1;

- }

- if (inf[1].desc == -2)

- if (same_files)

- inf[1].desc = inf[0].desc;

- else if ((inf[1].desc = open (inf[1].name, O_RDONLY, 0)) < 0)

- {

- perror_with_name (inf[1].name);

- failed = 1;

- }

-

-#if HAVE_SETMODE

- if (binary_I_O)

- for (i = 0; i <= 1; i++)

- if (0 <= inf[i].desc)

- setmode (inf[i].desc, O_BINARY);

-#endif

-

- /* Compare the files, if no error was found. */

-

- val = failed ? 2 : diff_2_files (inf, depth);

-

- /* Close the file descriptors. */

-

- if (inf[0].desc >= 0 && close (inf[0].desc) != 0)

- {

- perror_with_name (inf[0].name);

- val = 2;

- }

- if (inf[1].desc >= 0 && inf[0].desc != inf[1].desc

- && close (inf[1].desc) != 0)

- {

- perror_with_name (inf[1].name);

- val = 2;

- }

- }

-

- /* Now the comparison has been done, if no error prevented it,

- and VAL is the value this function will return. */

-

- if (val == 0 && !inf[0].dir_p)

- {

- if (print_file_same_flag)

- message ("Files %s and %s are identical\n",

- inf[0].name, inf[1].name);

- }

- else

- fflush (stdout);

-

- if (free0)

- free (free0);

- if (free1)

- free (free1);

-

- return val;

-}