FCHOWNAT(2) Linux Programmer's Manual FCHOWNAT(2)
fchownat - change ownership of a file relative to a directory file descriptor
#include <fcntl.h> /* Definition of AT_* constants */
int fchownat(int dirfd, const char *pathname,
uid_t owner, gid_t group, int flags);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
Since glibc 2.10:
_XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
The fchownat() system call operates in exactly the same way as chown(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 chown(2) for a relative pathname).
If pathname is relative and dirfd is the special value AT_FDCWD, then pathname is inter-
preted relative to the current working directory of the calling process (like chown(2)).
If pathname is absolute, then dirfd is ignored.
The flags argument is a bit mask created by ORing together 0 or more of the following val-
AT_EMPTY_PATH (since Linux 2.6.39)
If pathname is an empty string, operate on the file referred to by dirfd (which may
have been obtained using the open(2) O_PATH flag). In this case, dirfd can refer
to any type of file, not just a directory.
If pathname is a symbolic link, do not dereference it: instead operate on the link
itself, like lchown(2). (By default, fchownat() dereferences symbolic links, like
On success, fchownat() returns 0. On error, -1 is returned and errno is set to indicate
The same errors that occur for chown(2) can also occur for fchownat(). The following
additional errors can occur for fchownat():
EBADF dirfd is not a valid file descriptor.
EINVAL Invalid flag specified in flags.
pathname is relative and dirfd is a file descriptor referring to a file other than
fchownat() was added to Linux in kernel 2.6.16; library support was added to glibc in ver-
POSIX.1-2008. A similar system call exists on Solaris.
See openat(2) for an explanation of the need for fchownat().
chown(2), openat(2), path_resolution(7), symlink(7)
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Linux 2013-07-21 FCHOWNAT(2)