DIRFD(3)

NAME
dirfd - get directory stream file descriptor

SYNOPSIS
#include <sys/types.h>
#include <dirent.h>

int dirfd(DIR *dir);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

dirfd(): _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
The function dirfd() returns the file descriptor associated with the directory stream dir.

This descriptor is the one used internally by the directory stream. As a result, it is only useful 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 non-negative file descriptor is returned. On error, -1 is returned.

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.

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 only available if _BSD_SOURCE or _SVID_SOURCE is defined.

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 3.09 of the Linux man-pages project. A description of the project, and information about reporting documentation bugs, can be found at http://www.kernel.org/doc/man-pages/.