fchmodat - change permissions of a file relative to a directory file descriptor
SYNOPSIS
#define _ATFILE_SOURCE#include <fcntl.h> /* Definition of AT_* constants */#include <sys/stat.h>int fchmodat(int dirfd, const char *pathname, mode_t mode, int flags);
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 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().
This page is part of release 3.14 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/.
