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 cur-
              rently implemented.

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.

CONFORMING TO
       POSIX.1-2008.

NOTES
       See openat(2) for an explanation of the need for fchmodat().

SEE ALSO
       chmod(2), openat(2), path_resolution(7), symlink(7)

COLOPHON
       This  page  is  part of release 3.25 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                                                      2009-12-13                                                FCHMODAT(2)