/* Provide a stub lchown function for systems that lack it.
- Copyright (C) 1998, 1999 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ Copyright (C) 1998-1999, 2002, 2004, 2006-2007, 2009-2010 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.
+ the Free Software Foundation; either version 3 of the License, 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
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* written by Jim Meyering */
#include <config.h>
-#include <sys/types.h>
-#include <sys/stat.h>
+#include <unistd.h>
+
#include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
-#include "lchown.h"
-
-#ifdef STAT_MACROS_BROKEN
-# undef S_ISLNK
-#endif
-#if !defined(S_ISLNK) && defined(S_IFLNK)
-# define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
-#endif
-
-/* Declare chown to avoid a warning. Don't include unistd.h,
- because it may have a conflicting prototype for lchown. */
-int chown ();
+#include <stdbool.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#if !HAVE_LCHOWN
+
+/* If the system chown does not follow symlinks, we don't want it
+ replaced by gnulib's chown, which does follow symlinks. */
+# if CHOWN_MODIFIES_SYMLINK
+# undef chown
+# endif
/* Work just like chown, except when FILE is a symbolic link.
- In that case, set errno to ENOSYS and return -1. */
+ In that case, set errno to EOPNOTSUPP and return -1.
+ But if autoconf tests determined that chown modifies
+ symlinks, then just call chown. */
int
lchown (const char *file, uid_t uid, gid_t gid)
{
+# if HAVE_CHOWN
+# if ! CHOWN_MODIFIES_SYMLINK
struct stat stats;
if (lstat (file, &stats) == 0 && S_ISLNK (stats.st_mode))
{
- errno = ENOSYS;
+ errno = EOPNOTSUPP;
return -1;
}
+# endif
return chown (file, uid, gid);
+
+# else /* !HAVE_CHOWN */
+ errno = ENOSYS;
+ return -1;
+# endif
+}
+
+#else /* HAVE_LCHOWN */
+
+# undef lchown
+
+/* Work around trailing slash bugs in lchown. */
+int
+rpl_lchown (const char *file, uid_t uid, gid_t gid)
+{
+ bool stat_valid = false;
+ int result;
+
+# if CHOWN_CHANGE_TIME_BUG
+ struct stat st;
+
+ if (gid != (gid_t) -1 || uid != (uid_t) -1)
+ {
+ if (lstat (file, &st))
+ return -1;
+ stat_valid = true;
+ if (!S_ISLNK (st.st_mode))
+ return chown (file, uid, gid);
+ }
+# endif
+
+# if CHOWN_TRAILING_SLASH_BUG
+ if (!stat_valid)
+ {
+ size_t len = strlen (file);
+ if (len && file[len - 1] == '/')
+ return chown (file, uid, gid);
+ }
+# endif
+
+ result = lchown (file, uid, gid);
+
+# if CHOWN_CHANGE_TIME_BUG && HAVE_LCHMOD
+ if (result == 0 && stat_valid
+ && (uid == st.st_uid || uid == (uid_t) -1)
+ && (gid == st.st_gid || gid == (gid_t) -1))
+ {
+ /* No change in ownership, but at least one argument was not -1,
+ so we are required to update ctime. Since lchown succeeded,
+ we assume that lchmod will do likewise. But if the system
+ lacks lchmod and lutimes, we are out of luck. Oh well. */
+ result = lchmod (file, st.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO
+ | S_ISUID | S_ISGID | S_ISVTX));
+ }
+# endif
+
+ return result;
}
+
+#endif /* HAVE_LCHOWN */