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, dirfd() returns a file descriptor (a nonnegative integer).  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), openat(2), closedir(3), opendir(3), readdir(3), rewinddir(3), scandir(3), seekdir(3), telldir(3)

COLOPHON

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       information  about  reporting  bugs,  and  the  latest  version  of  this   page,   can   be   found   at
       https://www.kernel.org/doc/man-pages/.

Linux                                              2020-04-11                                           DIRFD(3)