xref: /netbsd-src/external/gpl2/xcvs/dist/lib/lstat.c (revision 5a6c14c844c4c665da5632061aebde7bb2cb5766)
1 /* Work around a bug of lstat on some systems
2 
3    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 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 #include <sys/cdefs.h>
20 __RCSID("$NetBSD: lstat.c,v 1.2 2016/05/17 14:00:09 christos Exp $");
21 
22 
23 /* written by Jim Meyering */
24 
25 #ifdef HAVE_CONFIG_H
26 # include <config.h>
27 #endif
28 
29 /* The specification of these functions is in sys_stat.h.  But we cannot
30    include this include file here, because on some systems, a
31    "#define lstat lstat64" is being used, and sys_stat.h deletes this
32    definition.  */
33 
34 #include <sys/types.h>
35 #include <sys/stat.h>
36 #include <stdlib.h>
37 #include <string.h>
38 
39 #include "stat-macros.h"
40 #include "xalloc.h"
41 
42 /* lstat works differently on Linux and Solaris systems.  POSIX (see
43    `pathname resolution' in the glossary) requires that programs like `ls'
44    take into consideration the fact that FILE has a trailing slash when
45    FILE is a symbolic link.  On Linux systems, the lstat function already
46    has the desired semantics (in treating `lstat("symlink/",sbuf)' just like
47    `lstat("symlink/.",sbuf)', but on Solaris it does not.
48 
49    If FILE has a trailing slash and specifies a symbolic link,
50    then append a `.' to FILE and call lstat a second time.  */
51 
52 int
rpl_lstat(const char * file,struct stat * sbuf)53 rpl_lstat (const char *file, struct stat *sbuf)
54 {
55   size_t len;
56   char *new_file;
57 
58   int lstat_result = lstat (file, sbuf);
59 
60   if (lstat_result != 0 || !S_ISLNK (sbuf->st_mode))
61     return lstat_result;
62 
63   len = strlen (file);
64   if (len == 0 || file[len - 1] != '/')
65     return lstat_result;
66 
67   /* FILE refers to a symbolic link and the name ends with a slash.
68      Append a `.' to FILE and repeat the lstat call.  */
69 
70   /* Add one for the `.' we'll append, and one more for the trailing NUL.  */
71   new_file = xmalloc (len + 1 + 1);
72   memcpy (new_file, file, len);
73   new_file[len] = '.';
74   new_file[len + 1] = 0;
75 
76   lstat_result = lstat (new_file, sbuf);
77   free (new_file);
78 
79   return lstat_result;
80 }
81