dirfd - get directory stream file descriptor
#include <sys/types.h>
#include <dirent.h>
int dirfd(DIR *dirp);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
dirfd():
/* Since glibc 2.10: */
_POSIX_C_SOURCE >= 200809L
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
The function
dirfd() returns the file descriptor associated with the
directory stream
dirp.
This file descriptor is the one used internally by the directory stream. As a
result, it is useful only for functions which do not depend on or alter the
file position, such as
fstat(2) and
fchdir(2). It will be
automatically closed when
closedir(3) is called.
On success, a nonnegative file descriptor is returned. On error, -1 is returned,
and
errno is set to indicate the cause of the error.
POSIX.1-2008 specifies two errors, neither of which is returned by the current
implementation.
- EINVAL
- dirp does not refer to a valid directory stream.
- ENOTSUP
- The implementation does not support the association of a file descriptor
with a directory.
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| dirfd () |
Thread safety |
MT-Safe |
POSIX.1-2008. This function was a BSD extension, present in 4.3BSD-Reno, not in
4.2BSD.
open(2),
closedir(3),
opendir(3),
readdir(3),
rewinddir(3),
scandir(3),
seekdir(3),
telldir(3)