DIRFD(3) Linux Programmer's Manual DIRFD(3)NAMEdirfd - 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():
_BSD_SOURCE || _SVID_SOURCE
|| /* Since glibc 2.10: */
(_POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 700)
DESCRIPTION
The function dirfd() returns the file descriptor associated with the
directory stream dirp.
This 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
Multithreading (see pthreads(7))
The dirfd() function is thread-safe.
CONFORMING TO
POSIX.1-2008. This function was a BSD extension, present in 4.3BSD-
Reno, not in 4.2BSD.
NOTES
The prototype for dirfd() is available only if _BSD_SOURCE or
_SVID_SOURCE is defined.
SEE ALSOopen(2), closedir(3), opendir(3), readdir(3), rewinddir(3), scandir(3),
seekdir(3), telldir(3)COLOPHON
This page is part of release 3.55 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2013-07-05 DIRFD(3)