FCHMODAT(2) Linux Programmer's Manual FCHMODAT(2)NAMEfchmodat - change permissions of a file relative to a directory file
descriptor
SYNOPSIS
#include <sys/stat.h>
int fchmodat(int dirfd, const char *path, 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 path is relative, then it is interpreted rela‐
tive 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 the pathname given in path is relative and dirfd is the special
value AT_FDCWD, then path is interpreted relative to the current work‐
ing directory of the calling process (like chmod(2)).
If the pathname given in path is absolute, then dirfd is ignored.
flags can either be 0, or include the following flag:
AT_SYMLINK_NOFOLLOW
If path is a symbolic link, do not dereference it: instead oper‐
ate 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
path is a relative path and dirfd is a file descriptor referring
to a file other than a directory.
ENOTSUP
flags specified AT_SYMLINK_NOFOLLOW, which is not supported.
NOTES
See openat(2) for an explanation of the need for fchmodat().
CONFORMING TO
This system call is non-standard but is proposed for inclusion in a
future revision of POSIX.1.
VERSIONSfchmodat() was added to Linux in kernel 2.6.16.
SEE ALSOchmod(2), openat(2), path_resolution(2)Linux 2.6.16 2006-05-05 FCHMODAT(2)