mirror of
https://github.com/coreutils/coreutils.git
synced 2024-12-03 06:53:31 +08:00
132 lines
3.7 KiB
C
132 lines
3.7 KiB
C
/* Determine whether two file names refer to the same file.
|
|
|
|
Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005 Free
|
|
Software Foundation, Inc.
|
|
|
|
This program 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.
|
|
|
|
This program 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 this program; if not, write to the Free Software Foundation,
|
|
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
|
|
|
|
/* written by Jim Meyering */
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
#include <stdbool.h>
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <ctype.h>
|
|
#include <errno.h>
|
|
|
|
#include <string.h>
|
|
|
|
#include <limits.h>
|
|
#ifndef _POSIX_NAME_MAX
|
|
# define _POSIX_NAME_MAX 14
|
|
#endif
|
|
|
|
#include "same.h"
|
|
#include "dirname.h"
|
|
#include "error.h"
|
|
#include "xalloc.h"
|
|
|
|
#ifndef MIN
|
|
# define MIN(a, b) ((a) < (b) ? (a) : (b))
|
|
#endif
|
|
|
|
#define SAME_INODE(Stat_buf_1, Stat_buf_2) \
|
|
((Stat_buf_1).st_ino == (Stat_buf_2).st_ino \
|
|
&& (Stat_buf_1).st_dev == (Stat_buf_2).st_dev)
|
|
|
|
/* Return nonzero if SOURCE and DEST point to the same name in the same
|
|
directory. */
|
|
|
|
bool
|
|
same_name (const char *source, const char *dest)
|
|
{
|
|
/* Compare the basenames. */
|
|
char const *source_basename = base_name (source);
|
|
char const *dest_basename = base_name (dest);
|
|
size_t source_baselen = base_len (source_basename);
|
|
size_t dest_baselen = base_len (dest_basename);
|
|
bool identical_basenames =
|
|
(source_baselen == dest_baselen
|
|
&& memcmp (source_basename, dest_basename, dest_baselen) == 0);
|
|
bool compare_dirs = identical_basenames;
|
|
bool same = false;
|
|
|
|
#if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
|
|
/* This implementation silently truncates components of file names. If
|
|
the base names might be truncated, check whether the truncated
|
|
base names are the same, while checking the directories. */
|
|
size_t slen_max = HAVE_LONG_FILE_NAMES ? 255 : _POSIX_NAME_MAX;
|
|
size_t min_baselen = MIN (source_baselen, dest_baselen);
|
|
if (slen_max <= min_baselen
|
|
&& memcmp (source_basename, dest_basename, slen_max) == 0)
|
|
compare_dirs = true;
|
|
#endif
|
|
|
|
if (compare_dirs)
|
|
{
|
|
struct stat source_dir_stats;
|
|
struct stat dest_dir_stats;
|
|
char *source_dirname, *dest_dirname;
|
|
|
|
/* Compare the parent directories (via the device and inode numbers). */
|
|
source_dirname = dir_name (source);
|
|
dest_dirname = dir_name (dest);
|
|
|
|
if (stat (source_dirname, &source_dir_stats))
|
|
{
|
|
/* Shouldn't happen. */
|
|
error (1, errno, "%s", source_dirname);
|
|
}
|
|
|
|
if (stat (dest_dirname, &dest_dir_stats))
|
|
{
|
|
/* Shouldn't happen. */
|
|
error (1, errno, "%s", dest_dirname);
|
|
}
|
|
|
|
same = SAME_INODE (source_dir_stats, dest_dir_stats);
|
|
|
|
#if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
|
|
if (same && ! identical_basenames)
|
|
{
|
|
long name_max = (errno = 0, pathconf (dest_dirname, _PC_NAME_MAX));
|
|
if (name_max < 0)
|
|
{
|
|
if (errno)
|
|
{
|
|
/* Shouldn't happen. */
|
|
error (1, errno, "%s", dest_dirname);
|
|
}
|
|
same = false;
|
|
}
|
|
else
|
|
same = (name_max <= min_baselen
|
|
&& memcmp (source_basename, dest_basename, name_max) == 0);
|
|
}
|
|
#endif
|
|
|
|
free (source_dirname);
|
|
free (dest_dirname);
|
|
}
|
|
|
|
return same;
|
|
}
|