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

NAME
       fchmodat  -  change  permissions of a file relative to a directory file
       descriptor
SYNOPSIS
       #include <fcntl.h>           /* Definition of AT_* constants */
       #include <sys/stat.h>
       int fchmodat(int dirfd, const char *pathname, mode_t mode, int flags);
   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
       fchmodat():
           Since glibc 2.10:
               _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:
               _ATFILE_SOURCE
DESCRIPTION
       The fchmodat()  system  call  operates  in  exactly  the  same  way  as
       chmod(2), except for the differences described in this manual page.
       If  the  pathname given in pathname is relative, then it is interpreted
       relative to the directory referred to  by  the  file  descriptor  dirfd
       (rather  than  relative to the current working directory of the calling
       process, as is done by chmod(2) for a relative pathname).
       If pathname is relative and dirfd is the special value  AT_FDCWD,  then
       pathname  is  interpreted  relative to the current working directory of
       the calling process (like chmod(2)).
       If pathname is absolute, then dirfd is ignored.
       flags can either be 0, or include the following flag:
       AT_SYMLINK_NOFOLLOW
              If pathname is a symbolic link, do not dereference  it:  instead
              operate  on  the link itself.  This flag is not currently imple-
              mented.
RETURN VALUE
       On success, fchmodat() returns 0.  On error, -1 is returned  and  errno
       is set to indicate the error.
ERRORS
       The  same errors that occur for chmod(2) can also occur for fchmodat().
       The following additional errors can occur for fchmodat():
       EBADF  dirfd is not a valid file descriptor.
       EINVAL Invalid flag specified in flags.
       ENOTDIR
              pathname is relative and dirfd is a file descriptor referring to
              a file other than a directory.
       ENOTSUP
              flags specified AT_SYMLINK_NOFOLLOW, which is not supported.
VERSIONS
       fchmodat()  was  added  to  Linux in kernel 2.6.16; library support was
       added to glibc in version 2.4.
CONFORMING TO
       POSIX.1-2008.
NOTES
       See openat(2) for an explanation of the need for fchmodat().
       The GNU C  library  wrapper  function  implements  the  POSIX-specified
       interface  described  in  this  page.   This interface differs from the
       underlying Linux system call, which does not have a flags argument.
SEE ALSO
       chmod(2), openat(2), path_resolution(7), symlink(7)
COLOPHON
       This page is part of release 3.53 of the Linux  man-pages  project.   A
       description  of  the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux                             2012-05-22                       FCHMODAT(2)