1 /* Determine whether two file names refer to the same file.
3 Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006 Free
4 Software Foundation, Inc.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
20 /* written by Jim Meyering */
28 #include <sys/types.h>
36 #ifndef _POSIX_NAME_MAX
37 # define _POSIX_NAME_MAX 14
43 #include "same-inode.h"
47 # define MIN(a, b) ((a) < (b) ? (a) : (b))
50 /* Return nonzero if SOURCE and DEST point to the same name in the same
54 same_name (const char *source, const char *dest)
56 /* Compare the basenames. */
57 char const *source_basename = last_component (source);
58 char const *dest_basename = last_component (dest);
59 size_t source_baselen = base_len (source_basename);
60 size_t dest_baselen = base_len (dest_basename);
61 bool identical_basenames =
62 (source_baselen == dest_baselen
63 && memcmp (source_basename, dest_basename, dest_baselen) == 0);
64 bool compare_dirs = identical_basenames;
67 #if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
68 /* This implementation silently truncates components of file names. If
69 the base names might be truncated, check whether the truncated
70 base names are the same, while checking the directories. */
71 size_t slen_max = HAVE_LONG_FILE_NAMES ? 255 : _POSIX_NAME_MAX;
72 size_t min_baselen = MIN (source_baselen, dest_baselen);
73 if (slen_max <= min_baselen
74 && memcmp (source_basename, dest_basename, slen_max) == 0)
80 struct stat source_dir_stats;
81 struct stat dest_dir_stats;
82 char *source_dirname, *dest_dirname;
84 /* Compare the parent directories (via the device and inode numbers). */
85 source_dirname = dir_name (source);
86 dest_dirname = dir_name (dest);
88 if (stat (source_dirname, &source_dir_stats))
90 /* Shouldn't happen. */
91 error (1, errno, "%s", source_dirname);
94 if (stat (dest_dirname, &dest_dir_stats))
96 /* Shouldn't happen. */
97 error (1, errno, "%s", dest_dirname);
100 same = SAME_INODE (source_dir_stats, dest_dir_stats);
102 #if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
103 if (same && ! identical_basenames)
105 long name_max = (errno = 0, pathconf (dest_dirname, _PC_NAME_MAX));
110 /* Shouldn't happen. */
111 error (1, errno, "%s", dest_dirname);
116 same = (name_max <= min_baselen
117 && memcmp (source_basename, dest_basename, name_max) == 0);
121 free (source_dirname);