dirfd(3c) [opensolaris man page]

dirfd(3C)						   Standard C Library Functions 						 dirfd(3C)

NAME

       dirfd - get directory stream file descriptor

SYNOPSIS

       #include <dirent.h>

       int dirfd(DIR *dir);

DESCRIPTION

       The dirfd() function returns the file descriptor associated with the directory stream dir.

       This  file  descriptor  is  the one used internally by the directory stream operations. See opendir(3C), closedir(3C), readdir(3C), rewind-
       dir(3C), seekdir(3C), telldir(3C).  The file descriptor is automatically closed when closedir() is called for the directory stream  dir	or
       when one of the exec functions is called.  See exec(2).

       The  file descriptor can safely be used only by functions that do not depend on or alter the file position, such as fstat(2) and fchdir(2).
       Closing the file descriptor with close(2) or modifying the file position by means other than the directory stream operations  listed  above
       causes undefined behavior to occur when one of the directory stream operations is subsequently called with the directory stream dir.

RETURN VALUES

       Upon  successful  completion,  the  dirfd() function returns an open file descriptor for the directory associated with the directory stream
       dir.

ERRORS

       There are no defined error returns.  Passing an invalid directory stream as an argument to the dirfd() function results in undefined behav-
       ior.

USAGE

       The dirfd() function is intended to be used to obtain a file descriptor for use with the fchdir() function.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed 		   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       close(2), exec(2), fchdir(2), fstat(2), closedir(3C), opendir(3C), readdir(3C), rewinddir(3C), seekdir(3C), telldir(3C), attributes(5)

SunOS 5.11							    24 Oct 2007 							 dirfd(3C)

Check Out this Related Man Page

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)

Linux and UNIX Man Pages

dirfd(3c) [opensolaris man page]

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