1/* Work around a bug of lstat on some systems
2
3   Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free
4   Software Foundation, Inc.
5
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)
9   any later version.
10
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.
15
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.  */
19
20/* written by Jim Meyering */
21
22#include <config.h>
23
24/* The specification of these functions is in sys_stat.h.  But we cannot
25   include this include file here, because on some systems, a
26   "#define lstat lstat64" is being used, and sys_stat.h deletes this
27   definition.  */
28
29#include <sys/types.h>
30#include <sys/stat.h>
31#include <string.h>
32#include <errno.h>
33
34/* lstat works differently on Linux and Solaris systems.  POSIX (see
35   `pathname resolution' in the glossary) requires that programs like
36   `ls' take into consideration the fact that FILE has a trailing slash
37   when FILE is a symbolic link.  On Linux and Solaris 10 systems, the
38   lstat function already has the desired semantics (in treating
39   `lstat ("symlink/", sbuf)' just like `lstat ("symlink/.", sbuf)',
40   but on Solaris 9 and earlier it does not.
41
42   If FILE has a trailing slash and specifies a symbolic link,
43   then use stat() to get more info on the referent of FILE.
44   If the referent is a non-directory, then set errno to ENOTDIR
45   and return -1.  Otherwise, return stat's result.  */
46
47int
48rpl_lstat (const char *file, struct stat *sbuf)
49{
50  size_t len;
51  int lstat_result = lstat (file, sbuf);
52
53  if (lstat_result != 0 || !S_ISLNK (sbuf->st_mode))
54    return lstat_result;
55
56  len = strlen (file);
57  if (len == 0 || file[len - 1] != '/')
58    return 0;
59
60  /* FILE refers to a symbolic link and the name ends with a slash.
61     Call stat() to get info about the link's referent.  */
62
63  /* If stat fails, then we do the same.  */
64  if (stat (file, sbuf) != 0)
65    return -1;
66
67  /* If FILE references a directory, return 0.  */
68  if (S_ISDIR (sbuf->st_mode))
69    return 0;
70
71  /* Here, we know stat succeeded and FILE references a non-directory.
72     But it was specified via a name including a trailing slash.
73     Fail with errno set to ENOTDIR to indicate the contradiction.  */
74  errno = ENOTDIR;
75  return -1;
76}
77