Jérôme Duval
434f9efa9a
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30823 a95241bf-73f2-0310-859d-f6bbb57e9c96
86 lines
2.5 KiB
C
86 lines
2.5 KiB
C
/* Define an at-style functions like fstatat, unlinkat, fchownat, etc.
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Copyright (C) 2006 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* written by Jim Meyering */
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#define CALL_FUNC(F) \
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(AT_FUNC_USE_F1_COND \
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? AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS) \
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: AT_FUNC_F2 (F AT_FUNC_POST_FILE_ARGS))
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/* Call AT_FUNC_F1 or AT_FUNC_F2 (testing AT_FUNC_USE_F1_COND to
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determine which) to operate on FILE, which is in the directory
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open on descriptor FD. If possible, do it without changing the
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working directory. Otherwise, resort to using save_cwd/fchdir,
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then AT_FUNC_F?/restore_cwd. If either the save_cwd or the restore_cwd
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fails, then give a diagnostic and exit nonzero. */
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int
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AT_FUNC_NAME (int fd, char const *file AT_FUNC_POST_FILE_PARAM_DECLS)
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{
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struct saved_cwd saved_cwd;
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int saved_errno;
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int err;
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if (fd == AT_FDCWD || IS_ABSOLUTE_FILE_NAME (file))
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return CALL_FUNC (file);
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{
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char buf[OPENAT_BUFFER_SIZE];
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char *proc_file = openat_proc_name (buf, fd, file);
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if (proc_file)
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{
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int proc_result = CALL_FUNC (proc_file);
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int proc_errno = errno;
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if (proc_file != buf)
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free (proc_file);
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/* If the syscall succeeds, or if it fails with an unexpected
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errno value, then return right away. Otherwise, fall through
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and resort to using save_cwd/restore_cwd. */
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if (0 <= proc_result)
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return proc_result;
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if (! EXPECTED_ERRNO (proc_errno))
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{
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errno = proc_errno;
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return proc_result;
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}
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}
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}
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if (save_cwd (&saved_cwd) != 0)
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openat_save_fail (errno);
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if (fchdir (fd) != 0)
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{
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saved_errno = errno;
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free_cwd (&saved_cwd);
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errno = saved_errno;
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return -1;
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}
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err = CALL_FUNC (file);
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saved_errno = (err < 0 ? errno : 0);
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if (restore_cwd (&saved_cwd) != 0)
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openat_restore_fail (errno);
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free_cwd (&saved_cwd);
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if (saved_errno)
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errno = saved_errno;
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return err;
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}
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#undef CALL_FUNC
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