dirfd(3)

NAME
dirfd - get directory stream file descriptor

LIBRARY
Standard C library (libc, -lc)

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 <= 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).
Interface | Attribute | Value
 | Thread safety | MT-Safe

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)