unlinkat() - Unix, Linux System Call
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NAME
unlinkat - remove a directory entry relative to a directory file descriptor
SYNOPSIS
#include <fcntl.h>
int unlinkat(int dirfd, const char *pathname, int flags);
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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(). Currently only one such flags is defined:
Tag | Description |
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():
Tag | Description |
EBADF |
dirfd is not a valid file descriptor.
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EINVAL |
An invalid flag value was specified in
flags. |
ENOTDIR |
pathname is a relative path and
dirfd is a file descriptor referring to a file other than a directory.
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NOTES
See openat(2)
for an explanation of the need for
unlinkat().
CONFORMING TO
This system call is non-standard but is proposed
for inclusion in a future revision of POSIX.1.
A similar system call exists on Solaris.
VERSIONS
unlinkat() was added to Linux in kernel 2.6.16.
SEE ALSO
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