1dirfd(3)                   Library Functions Manual                   dirfd(3)
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3
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NAME

6       dirfd - get directory stream file descriptor
7

LIBRARY

9       Standard C library (libc, -lc)
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SYNOPSIS

12       #include <sys/types.h>
13       #include <dirent.h>
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15       int dirfd(DIR *dirp);
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17   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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19       dirfd():
20           /* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200809L
21               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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DESCRIPTION

24       The  function  dirfd()  returns the file descriptor associated with the
25       directory stream dirp.
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27       This file descriptor is  the  one  used  internally  by  the  directory
28       stream.   As a result, it is useful only for functions which do not de‐
29       pend on or alter the file position, such as fstat(2) and fchdir(2).  It
30       will be automatically closed when closedir(3) is called.
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RETURN VALUE

33       On  success, dirfd() returns a file descriptor (a nonnegative integer).
34       On error, -1 is returned, and errno is set to indicate the error.
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ERRORS

37       POSIX.1-2008 specifies two errors, neither of which is returned by  the
38       current implementation.
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40       EINVAL dirp does not refer to a valid directory stream.
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42       ENOTSUP
43              The  implementation  does  not support the association of a file
44              descriptor with a directory.
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ATTRIBUTES

47       For an  explanation  of  the  terms  used  in  this  section,  see  at‐
48       tributes(7).
49
50       ┌────────────────────────────────────────────┬───────────────┬─────────┐
51       │Interface                                   │ Attribute     │ Value   │
52       ├────────────────────────────────────────────┼───────────────┼─────────┤
53       │dirfd()                                     │ Thread safety │ MT-Safe │
54       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

57       POSIX.1-2008.
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HISTORY

60       4.3BSD-Reno (not in 4.2BSD).
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SEE ALSO

63       open(2),  openat(2), closedir(3), opendir(3), readdir(3), rewinddir(3),
64       scandir(3), seekdir(3), telldir(3)
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68Linux man-pages 6.04              2023-03-30                          dirfd(3)
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