1FCHMODAT(2)                Linux Programmer's Manual               FCHMODAT(2)
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NAME

6       fchmodat  -  change  permissions of a file relative to a directory file
7       descriptor
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SYNOPSIS

10       #include <fcntl.h>           /* Definition of AT_* constants */
11       #include <sys/stat.h>
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13       int fchmodat(int dirfd, const char *pathname, mode_t mode, int flags);
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15   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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17       fchmodat():
18           Since glibc 2.10:
19               _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
20           Before glibc 2.10:
21               _ATFILE_SOURCE
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DESCRIPTION

24       The fchmodat()  system  call  operates  in  exactly  the  same  way  as
25       chmod(2), except for the differences described in this manual page.
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27       If  the  pathname given in pathname is relative, then it is interpreted
28       relative to the directory referred to  by  the  file  descriptor  dirfd
29       (rather  than  relative to the current working directory of the calling
30       process, as is done by chmod(2) for a relative pathname).
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32       If pathname is relative and dirfd is the special value  AT_FDCWD,  then
33       pathname  is  interpreted  relative to the current working directory of
34       the calling process (like chmod(2)).
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36       If pathname is absolute, then dirfd is ignored.
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38       flags can either be 0, or include the following flag:
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40       AT_SYMLINK_NOFOLLOW
41              If pathname is a symbolic link, do not dereference  it:  instead
42              operate  on  the link itself.  This flag is not currently imple‐
43              mented.
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RETURN VALUE

46       On success, fchmodat() returns 0.  On error, -1 is returned  and  errno
47       is set to indicate the error.
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ERRORS

50       The  same errors that occur for chmod(2) can also occur for fchmodat().
51       The following additional errors can occur for fchmodat():
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53       EBADF  dirfd is not a valid file descriptor.
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55       EINVAL Invalid flag specified in flags.
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57       ENOTDIR
58              pathname is relative and dirfd is a file descriptor referring to
59              a file other than a directory.
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61       ENOTSUP
62              flags specified AT_SYMLINK_NOFOLLOW, which is not supported.
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VERSIONS

65       fchmodat()  was  added  to  Linux in kernel 2.6.16; library support was
66       added to glibc in version 2.4.
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CONFORMING TO

69       POSIX.1-2008.
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NOTES

72       See openat(2) for an explanation of the need for fchmodat().
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74       The GNU C  library  wrapper  function  implements  the  POSIX-specified
75       interface  described  in  this  page.   This interface differs from the
76       underlying Linux system call, which does not have a flags argument.
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SEE ALSO

79       chmod(2), openat(2), path_resolution(7), symlink(7)
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COLOPHON

82       This page is part of release 3.53 of the Linux  man-pages  project.   A
83       description  of  the project, and information about reporting bugs, can
84       be found at http://www.kernel.org/doc/man-pages/.
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88Linux                             2012-05-22                       FCHMODAT(2)
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