dirfd(3) — Linux manual page


DIRFD(3)                  Linux Programmer's Manual                 DIRFD(3)

NAME         top

       dirfd - get directory stream file descriptor

SYNOPSIS         top

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

       int dirfd(DIR *dirp);

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

           /* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200809L
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION         top

       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         top

       On success, dirfd() returns a file descriptor (a nonnegative
       integer).  On error, -1 is returned, and errno is set to indicate the
       cause of the error.

ERRORS         top

       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.

              The implementation does not support the association of a file
              descriptor with a directory.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface Attribute     Value   │
       │dirfd()   │ Thread safety │ MT-Safe │

CONFORMING TO         top

       POSIX.1-2008.  This function was a BSD extension, present in 4.3BSD-
       Reno, not in 4.2BSD.

SEE ALSO         top

       open(2), openat(2), closedir(3), opendir(3), readdir(3),
       rewinddir(3), scandir(3), seekdir(3), telldir(3)

COLOPHON         top

       This page is part of release 5.08 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

Linux                            2020-04-11                         DIRFD(3)

Pages that refer to this page: creat(2)open(2)openat(2)fdopendir(3)opendir(3)readdir(3)