dirfd(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON

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)):

       dirfd():
           /* 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.

       ENOTSUP
              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
       attributes(7).

       ┌──────────┬───────────────┬─────────┐
       │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
       https://www.kernel.org/doc/man-pages/.

Linux                            2020-04-11                         DIRFD(3)

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