dirfd - get directory stream file descriptor
Standard C library (
libc,
-lc)
#include <sys/types.h>
#include <dirent.h>
int dirfd(DIR *dirp);
dirfd():
/* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200809L
|| /* glibc <= 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,
dirfd() returns a file descriptor (a nonnegative integer). On
error, -1 is returned, and
errno is set to indicate 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),
openat(2),
closedir(3),
opendir(3),
readdir(3),
rewinddir(3),
scandir(3),
seekdir(3),
telldir(3)