1 /* Define an at-style functions like fstatat, unlinkat, fchownat, etc.
2 Copyright (C) 2006 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* written by Jim Meyering */
19 #define CALL_FUNC(F) \
20 (AT_FUNC_USE_F1_COND \
21 ? AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS) \
22 : AT_FUNC_F2 (F AT_FUNC_POST_FILE_ARGS))
24 /* Call AT_FUNC_F1 or AT_FUNC_F2 (testing AT_FUNC_USE_F1_COND to
25 determine which) to operate on FILE, which is in the directory
26 open on descriptor FD. If possible, do it without changing the
27 working directory. Otherwise, resort to using save_cwd/fchdir,
28 then AT_FUNC_F?/restore_cwd. If either the save_cwd or the restore_cwd
29 fails, then give a diagnostic and exit nonzero. */
31 AT_FUNC_NAME (int fd, char const *file AT_FUNC_POST_FILE_PARAM_DECLS)
33 struct saved_cwd saved_cwd;
37 if (fd == AT_FDCWD || IS_ABSOLUTE_FILE_NAME (file))
38 return CALL_FUNC (file);
41 char buf[OPENAT_BUFFER_SIZE];
42 char *proc_file = openat_proc_name (buf, fd, file);
45 int proc_result = CALL_FUNC (proc_file);
46 int proc_errno = errno;
49 /* If the syscall succeeds, or if it fails with an unexpected
50 errno value, then return right away. Otherwise, fall through
51 and resort to using save_cwd/restore_cwd. */
54 if (! EXPECTED_ERRNO (proc_errno))
62 if (save_cwd (&saved_cwd) != 0)
63 openat_save_fail (errno);
68 free_cwd (&saved_cwd);
73 err = CALL_FUNC (file);
74 saved_errno = (err < 0 ? errno : 0);
76 if (restore_cwd (&saved_cwd) != 0)
77 openat_restore_fail (errno);
79 free_cwd (&saved_cwd);