UNLINKAT(2) Linux Programmer's Manual UNLINKAT(2)
NAME
unlinkat - remove a directory entry relative to a directory file
descriptor
SYNOPSIS
#include <fcntl.h> /* Definition of AT_* constants */
#include <unistd.h>
int unlinkat(int dirfd, const char *pathname, int flags);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
unlinkat():
Since glibc 2.10:
_XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_ATFILE_SOURCE
DESCRIPTION
The unlinkat() system call operates in exactly the same way as either
unlink(2) or rmdir(2) (depending on whether or not flags includes the
AT_REMOVEDIR flag) 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 unlink(2) and rmdir(2) for a relative pathname).
If the pathname given in 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 unlink(2) and rmdir(2)).
If the pathname given in pathname is absolute, then dirfd is ignored.
flags is a bit mask that can either be specified as 0, or by ORing
together flag values that control the operation of unlinkat(). Cur-
rently only one such flag is defined:
AT_REMOVEDIR
By default, unlinkat() performs the equivalent of unlink(2) on
pathname. If the AT_REMOVEDIR flag is specified, then performs
the equivalent of rmdir(2) on pathname.
RETURN VALUE
On success, unlinkat() returns 0. On error, -1 is returned and errno
is set to indicate the error.
ERRORS
The same errors that occur for unlink(2) and rmdir(2) can also occur
for unlinkat(). The following additional errors can occur for
unlinkat():
EBADF dirfd is not a valid file descriptor.
EINVAL An invalid flag value was specified in flags.
ENOTDIR
pathname is relative and dirfd is a file descriptor referring to
a file other than a directory.
VERSIONS
unlinkat() was added to Linux in kernel 2.6.16; library support was
added to glibc in version 2.4.
CONFORMING TO
POSIX.1-2008. A similar system call exists on Solaris.
NOTES
See openat(2) for an explanation of the need for unlinkat().
SEE ALSO
openat(2), rmdir(2), unlink(2), path_resolution(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 2012-05-04 UNLINKAT(2)