1 /* Work around a bug of lstat on some systems
2
3 Copyright (C) 1997-2006, 2008-2023 Free Software Foundation, Inc.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file 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 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 /* written by Jim Meyering */
19
20 /* If the user's config.h happens to include <sys/stat.h>, let it include only
21 the system's <sys/stat.h> here, so that orig_lstat doesn't recurse to
22 rpl_lstat. */
23 #define __need_system_sys_stat_h
24 #include <config.h>
25
26 #if !HAVE_LSTAT
27 /* On systems that lack symlinks, our replacement <sys/stat.h> already
28 defined lstat as stat, so there is nothing further to do other than
29 avoid an empty file. */
30 typedef int dummy;
31 #else /* HAVE_LSTAT */
32
33 /* Get the original definition of lstat. It might be defined as a macro. */
34 # include <sys/types.h>
35 # include <sys/stat.h>
36 # undef __need_system_sys_stat_h
37
38 static int
39 orig_lstat (const char *filename, struct stat *buf)
40 {
41 return lstat (filename, buf);
42 }
43
44 /* Specification. */
45 # ifdef __osf__
46 /* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc
47 eliminates this include because of the preliminary #include <sys/stat.h>
48 above. */
49 # include "sys/stat.h"
50 # else
51 # include <sys/stat.h>
52 # endif
53
54 # include "stat-time.h"
55
56 # include <string.h>
57 # include <errno.h>
58
59 /* lstat works differently on Linux and Solaris systems. POSIX (see
60 "pathname resolution" in the glossary) requires that programs like
61 'ls' take into consideration the fact that FILE has a trailing slash
62 when FILE is a symbolic link. On Linux and Solaris 10 systems, the
63 lstat function already has the desired semantics (in treating
64 'lstat ("symlink/", sbuf)' just like 'lstat ("symlink/.", sbuf)',
65 but on Solaris 9 and earlier it does not.
66
67 If FILE has a trailing slash and specifies a symbolic link,
68 then use stat() to get more info on the referent of FILE.
69 If the referent is a non-directory, then set errno to ENOTDIR
70 and return -1. Otherwise, return stat's result. */
71
72 int
73 rpl_lstat (const char *file, struct stat *sbuf)
74 {
75 int result = orig_lstat (file, sbuf);
76
77 /* This replacement file can blindly check against '/' rather than
78 using the ISSLASH macro, because all platforms with '\\' either
79 lack symlinks (mingw) or have working lstat (cygwin) and thus do
80 not compile this file. 0 len should have already been filtered
81 out above, with a failure return of ENOENT. */
82 if (result == 0)
83 {
84 if (S_ISDIR (sbuf->st_mode) || file[strlen (file) - 1] != '/')
85 result = stat_time_normalize (result, sbuf);
86 else
87 {
88 /* At this point, a trailing slash is permitted only on
89 symlink-to-dir; but it should have found information on the
90 directory, not the symlink. Call 'stat' to get info about the
91 link's referent. Our replacement stat guarantees valid results,
92 even if the symlink is not pointing to a directory. */
93 if (!S_ISLNK (sbuf->st_mode))
94 {
95 errno = ENOTDIR;
96 return -1;
97 }
98 result = stat (file, sbuf);
99 }
100 }
101 return result;
102 }
103
104 #endif /* HAVE_LSTAT */