dirfd(3) - Linux manual page (original) (raw)

dirfd(3) Library Functions Manual dirfd(3)

NAME top

   dirfd - get directory stream file descriptor

LIBRARY top

   Standard C library (_libc_, _-lc_)

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 <= 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)](../man2/fstat.2.html) and
   [fchdir(2)](../man2/fchdir.2.html).  It will be automatically closed when [closedir(3)](../man3/closedir.3.html) is
   called.

RETURN VALUE top

   On success, **dirfd**() returns a file descriptor (a nonnegative
   integer).  On error, -1 is returned, and _[errno](../man3/errno.3.html)_ is set to indicate
   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)](../man7/attributes.7.html).
   ┌─────────────────────────────────────┬───────────────┬─────────┐
   │ **Interface** │ **Attribute** │ **Value** │
   ├─────────────────────────────────────┼───────────────┼─────────┤
   │ **dirfd**()                             │ Thread safety │ MT-Safe │
   └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS top

   POSIX.1-2008.

HISTORY top

   4.3BSD-Reno (not in 4.2BSD).

SEE ALSO top

   [open(2)](../man2/open.2.html), [openat(2)](../man2/openat.2.html), [closedir(3)](../man3/closedir.3.html), [opendir(3)](../man3/opendir.3.html), [readdir(3)](../man3/readdir.3.html),
   [rewinddir(3)](../man3/rewinddir.3.html), [scandir(3)](../man3/scandir.3.html), [seekdir(3)](../man3/seekdir.3.html), [telldir(3)](../man3/telldir.3.html)

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Linux man-pages 6.9.1 2024-05-02 dirfd(3)

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