1 /* Work around a bug of lstat on some systems
2
3 Copyright (C) 1997-1999, 2000-2006, 2008 Free Software Foundation, Inc.
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17
18 /* written by Jim Meyering */
19
20 #include <config.h>
21
22 /* Get the original definition of open. It might be defined as a macro. */
23 #define __need_system_sys_stat_h
24 #include <sys/types.h>
25 #include <sys/stat.h>
26 #undef __need_system_sys_stat_h
27
28 static inline int
orig_lstat(const char * filename,struct stat * buf)29 orig_lstat (const char *filename, struct stat *buf)
30 {
31 return lstat (filename, buf);
32 }
33
34 /* Specification. */
35 #include <sys/stat.h>
36
37 #include <string.h>
38 #include <errno.h>
39
40 /* lstat works differently on Linux and Solaris systems. POSIX (see
41 `pathname resolution' in the glossary) requires that programs like
42 `ls' take into consideration the fact that FILE has a trailing slash
43 when FILE is a symbolic link. On Linux and Solaris 10 systems, the
44 lstat function already has the desired semantics (in treating
45 `lstat ("symlink/", sbuf)' just like `lstat ("symlink/.", sbuf)',
46 but on Solaris 9 and earlier it does not.
47
48 If FILE has a trailing slash and specifies a symbolic link,
49 then use stat() to get more info on the referent of FILE.
50 If the referent is a non-directory, then set errno to ENOTDIR
51 and return -1. Otherwise, return stat's result. */
52
53 int
rpl_lstat(const char * file,struct stat * sbuf)54 rpl_lstat (const char *file, struct stat *sbuf)
55 {
56 size_t len;
57 int lstat_result = orig_lstat (file, sbuf);
58
59 if (lstat_result != 0 || !S_ISLNK (sbuf->st_mode))
60 return lstat_result;
61
62 len = strlen (file);
63 if (len == 0 || file[len - 1] != '/')
64 return 0;
65
66 /* FILE refers to a symbolic link and the name ends with a slash.
67 Call stat() to get info about the link's referent. */
68
69 /* If stat fails, then we do the same. */
70 if (stat (file, sbuf) != 0)
71 return -1;
72
73 /* If FILE references a directory, return 0. */
74 if (S_ISDIR (sbuf->st_mode))
75 return 0;
76
77 /* Here, we know stat succeeded and FILE references a non-directory.
78 But it was specified via a name including a trailing slash.
79 Fail with errno set to ENOTDIR to indicate the contradiction. */
80 errno = ENOTDIR;
81 return -1;
82 }
83