+++ /dev/null
-/* provide consistent interface to chown for systems that don't interpret
- an ID of -1 as meaning `don't change the corresponding ID'.
-
- Copyright (C) 1997, 2004-2007, 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 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
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- 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, see <http://www.gnu.org/licenses/>. */
-
-/* written by Jim Meyering */
-
-#include <config.h>
-
-/* Specification. */
-#include <unistd.h>
-
-#include <errno.h>
-#include <fcntl.h>
-#include <stdbool.h>
-#include <string.h>
-#include <sys/stat.h>
-
-#if !HAVE_CHOWN
-
-/* Simple stub that always fails with ENOSYS, for mingw. */
-int
-chown (const char *file _GL_UNUSED, uid_t uid _GL_UNUSED,
- gid_t gid _GL_UNUSED)
-{
- errno = ENOSYS;
- return -1;
-}
-
-#else /* HAVE_CHOWN */
-
-/* Below we refer to the system's chown(). */
-# undef chown
-
-/* The results of open() in this file are not used with fchdir,
- therefore save some unnecessary work in fchdir.c. */
-# undef open
-# undef close
-
-/* Provide a more-closely POSIX-conforming version of chown on
- systems with one or both of the following problems:
- - chown doesn't treat an ID of -1 as meaning
- `don't change the corresponding ID'.
- - chown doesn't dereference symlinks. */
-
-int
-rpl_chown (const char *file, uid_t uid, gid_t gid)
-{
- struct stat st;
- bool stat_valid = false;
- int result;
-
-# if CHOWN_CHANGE_TIME_BUG
- if (gid != (gid_t) -1 || uid != (uid_t) -1)
- {
- if (stat (file, &st))
- return -1;
- stat_valid = true;
- }
-# endif
-
-# if CHOWN_FAILS_TO_HONOR_ID_OF_NEGATIVE_ONE
- if (gid == (gid_t) -1 || uid == (uid_t) -1)
- {
- /* Stat file to get id(s) that should remain unchanged. */
- if (!stat_valid && stat (file, &st))
- return -1;
- if (gid == (gid_t) -1)
- gid = st.st_gid;
- if (uid == (uid_t) -1)
- uid = st.st_uid;
- }
-# endif
-
-# if CHOWN_MODIFIES_SYMLINK
- {
- /* Handle the case in which the system-supplied chown function
- does *not* follow symlinks. Instead, it changes permissions
- on the symlink itself. To work around that, we open the
- file (but this can fail due to lack of read or write permission) and
- use fchown on the resulting descriptor. */
- int open_flags = O_NONBLOCK | O_NOCTTY;
- int fd = open (file, O_RDONLY | open_flags);
- if (0 <= fd
- || (errno == EACCES
- && 0 <= (fd = open (file, O_WRONLY | open_flags))))
- {
- int saved_errno;
- bool fchown_socket_failure;
-
- result = fchown (fd, uid, gid);
- saved_errno = errno;
-
- /* POSIX says fchown can fail with errno == EINVAL on sockets
- and pipes, so fall back on chown in that case. */
- fchown_socket_failure =
- (result != 0 && saved_errno == EINVAL
- && fstat (fd, &st) == 0
- && (S_ISFIFO (st.st_mode) || S_ISSOCK (st.st_mode)));
-
- close (fd);
-
- if (! fchown_socket_failure)
- {
- errno = saved_errno;
- return result;
- }
- }
- else if (errno != EACCES)
- return -1;
- }
-# endif
-
-# if CHOWN_TRAILING_SLASH_BUG
- if (!stat_valid)
- {
- size_t len = strlen (file);
- if (len && file[len - 1] == '/' && stat (file, &st))
- return -1;
- }
-# endif
-
- result = chown (file, uid, gid);
-
-# if CHOWN_CHANGE_TIME_BUG
- 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 chown succeeded,
- we assume that chmod will do likewise. Fortunately, on all
- known systems where a 'no-op' chown skips the ctime update, a
- 'no-op' chmod still does the trick. */
- result = chmod (file, st.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO
- | S_ISUID | S_ISGID | S_ISVTX));
- }
-# endif
-
- return result;
-}
-
-#endif /* HAVE_CHOWN */