Manpages - dirfd.3

dirfd - get directory stream file descriptor

  #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

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.

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

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.

For an explanation of the terms used in this section, see *attributes*(7).

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

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

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