DIRFD
Section: Linux Programmer's Manual (3)
Updated: 2020-04-11
Page Index
NAME
dirfd - get directory stream file descriptor
SYNOPSIS
#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
DESCRIPTION
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.
RETURN VALUE
On success,
dirfd()
returns a file descriptor (a nonnegative integer).
On error, -1 is returned, and
errno
is set to indicate the cause of the error.
ERRORS
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.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
dirfd()
| Thread safety | MT-Safe
|
CONFORMING TO
POSIX.1-2008.
This function was a BSD extension, present in 4.3BSD-Reno, not in 4.2BSD.
SEE ALSO
open(2),
openat(2),
closedir(3),
opendir(3),
readdir(3),
rewinddir(3),
scandir(3),
seekdir(3),
telldir(3)
COLOPHON
This page is part of release 5.10 of the Linux
man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
https://www.kernel.org/doc/man-pages/.