DIRFD(3) Linux Programmer's Manual DIRFD(3)
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, a nonnegative file descriptor is returned. 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), closedir(3), opendir(3), readdir(3), rewinddir(3), scandir(3),
seekdir(3), telldir(3)
COLOPHON
This page is part of release 4.15 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/.
Linux 2016-03-15 DIRFD(3)