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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 4.16 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)