dirfd(3) Library Functions Manual 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 di-
rectory 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 au-
tomatically 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 de-
scriptor 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 │
└────────────────────────────────────────────┴───────────────┴─────────┘
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)
Linux man-pages 6.9.1 2024-05-02 dirfd(3)
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