dirfd(3)

NAME#

dirfd - get directory stream file descriptor

LIBRARY#

Standard C library (libc, -lc)

SYNOPSIS#

#include <sys/types.h>\n
\n#include <dirent.h>

int dirfd(DIR *\ndirp\n);

dirfd():

\n
    /* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200809L
\n
        || /* glibc <= 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 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).

STANDARDS#

POSIX.1-2008.

HISTORY#

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)