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

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       found at https://www.kernel.org/doc/man-pages/.