1 .\" Copyright (C) 2002 Andries Brouwer (aeb@cwi.nl)
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25 .TH DIRFD 3 2021-03-22 "Linux" "Linux Programmer's Manual"
27 dirfd \- get directory stream file descriptor
30 .B #include <sys/types.h>
31 .B #include <dirent.h>
33 .BI "int dirfd(DIR *" dirp );
37 Feature Test Macro Requirements for glibc (see
38 .BR feature_test_macros (7)):
43 /* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200809L
44 || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
49 returns the file descriptor associated with the directory stream
52 This file descriptor is the one used internally by the directory stream.
53 As a result, it is useful only for functions which do not depend on
54 or alter the file position, such as
58 It will be automatically closed when
64 returns a file descriptor (a nonnegative integer).
65 On error, \-1 is returned, and
67 is set to indicate the error.
69 POSIX.1-2008 specifies two errors,
70 neither of which is returned by the current
76 does not refer to a valid directory stream.
79 The implementation does not support the association of a file
80 descriptor with a directory.
82 For an explanation of the terms used in this section, see
90 Interface Attribute Value
93 T} Thread safety MT-Safe
100 This function was a BSD extension, present in 4.3BSD-Reno, not in 4.2BSD.
101 .\" It is present in libc5 (since 5.1.2) and in glibc2.