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129 lines
3.6 KiB
C
129 lines
3.6 KiB
C
/* Determine whether two file names refer to the same file.
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Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006 Free
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Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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/* written by Jim Meyering */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <stdbool.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <ctype.h>
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#include <errno.h>
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#include <string.h>
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#include <limits.h>
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#ifndef _POSIX_NAME_MAX
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# define _POSIX_NAME_MAX 14
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#endif
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#include "same.h"
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#include "dirname.h"
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#include "error.h"
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#include "same-inode.h"
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#include "xalloc.h"
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#ifndef MIN
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# define MIN(a, b) ((a) < (b) ? (a) : (b))
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#endif
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/* Return nonzero if SOURCE and DEST point to the same name in the same
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directory. */
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bool
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same_name (const char *source, const char *dest)
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{
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/* Compare the basenames. */
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char const *source_basename = last_component (source);
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char const *dest_basename = last_component (dest);
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size_t source_baselen = base_len (source_basename);
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size_t dest_baselen = base_len (dest_basename);
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bool identical_basenames =
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(source_baselen == dest_baselen
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&& memcmp (source_basename, dest_basename, dest_baselen) == 0);
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bool compare_dirs = identical_basenames;
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bool same = false;
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#if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
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/* This implementation silently truncates components of file names. If
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the base names might be truncated, check whether the truncated
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base names are the same, while checking the directories. */
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size_t slen_max = HAVE_LONG_FILE_NAMES ? 255 : _POSIX_NAME_MAX;
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size_t min_baselen = MIN (source_baselen, dest_baselen);
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if (slen_max <= min_baselen
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&& memcmp (source_basename, dest_basename, slen_max) == 0)
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compare_dirs = true;
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#endif
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if (compare_dirs)
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{
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struct stat source_dir_stats;
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struct stat dest_dir_stats;
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char *source_dirname, *dest_dirname;
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/* Compare the parent directories (via the device and inode numbers). */
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source_dirname = dir_name (source);
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dest_dirname = dir_name (dest);
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if (stat (source_dirname, &source_dir_stats))
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{
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/* Shouldn't happen. */
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error (1, errno, "%s", source_dirname);
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}
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if (stat (dest_dirname, &dest_dir_stats))
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{
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/* Shouldn't happen. */
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error (1, errno, "%s", dest_dirname);
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}
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same = SAME_INODE (source_dir_stats, dest_dir_stats);
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#if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
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if (same && ! identical_basenames)
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{
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long name_max = (errno = 0, pathconf (dest_dirname, _PC_NAME_MAX));
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if (name_max < 0)
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{
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if (errno)
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{
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/* Shouldn't happen. */
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error (1, errno, "%s", dest_dirname);
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}
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same = false;
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}
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else
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same = (name_max <= min_baselen
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&& memcmp (source_basename, dest_basename, name_max) == 0);
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}
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#endif
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free (source_dirname);
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free (dest_dirname);
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}
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return same;
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}
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