minix man page for dirfd

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

NAME
       dirfd - get directory stream file descriptor

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 versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       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
       On success, a nonnegative file descriptor is returned.  On error, -1 is returned, and errno is set to indicate the cause of 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 descriptor 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 |
       +----------+---------------+---------+
CONFORMING TO
       POSIX.1-2008.  This function was a BSD extension, present in 4.3BSD-Reno, not in 4.2BSD.

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

COLOPHON
       This page is part of release 4.15 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								    2016-03-15								  DIRFD(3)