unlinkat.2: Convert to link to unlink.2

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
Michael Kerrisk 2014-02-21 11:21:05 +01:00
parent beafa3e021
commit ee9c4ceabf
1 changed files with 1 additions and 173 deletions

View File

@ -1,173 +1 @@
.\" This manpage is Copyright (C) 2006, Michael Kerrisk
.\"
.\" %%%LICENSE_START(VERBATIM)
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date. The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein. The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\" %%%LICENSE_END
.\"
.TH UNLINKAT 2 2014-01-22 "Linux" "Linux Programmer's Manual"
.SH NAME
unlinkat \- remove a directory entry relative to a directory file descriptor
.SH SYNOPSIS
.nf
.B #include <fcntl.h> /* Definition of AT_* constants */
.B #include <unistd.h>
.sp
.BI "int unlinkat(int " dirfd ", const char *" pathname ", int " flags );
.fi
.sp
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
.sp
.BR unlinkat ():
.PD 0
.ad l
.RS 4
.TP 4
Since glibc 2.10:
_XOPEN_SOURCE\ >=\ 700 || _POSIX_C_SOURCE\ >=\ 200809L
.TP
Before glibc 2.10:
_ATFILE_SOURCE
.RE
.ad
.PD
.SH DESCRIPTION
The
.BR unlinkat ()
system call operates in exactly the same way as either
.BR unlink (2)
or
.BR rmdir (2)
(depending on whether or not
.I flags
includes the
.B AT_REMOVEDIR
flag)
except for the differences described in this manual page.
If the pathname given in
.I pathname
is relative, then it is interpreted relative to the directory
referred to by the file descriptor
.I dirfd
(rather than relative to the current working directory of
the calling process, as is done by
.BR unlink (2)
and
.BR rmdir (2)
for a relative pathname).
If the pathname given in
.I pathname
is relative and
.I dirfd
is the special value
.BR AT_FDCWD ,
then
.I pathname
is interpreted relative to the current working
directory of the calling process (like
.BR unlink (2)
and
.BR rmdir (2)).
If the pathname given in
.I pathname
is absolute, then
.I dirfd
is ignored.
.I flags
is a bit mask that can either be specified as 0, or by ORing
together flag values that control the operation of
.BR unlinkat ().
Currently only one such flag is defined:
.TP
.B AT_REMOVEDIR
By default,
.BR unlinkat ()
performs the equivalent of
.BR unlink (2)
on
.IR pathname .
If the
.B AT_REMOVEDIR
flag is specified, then
performs the equivalent of
.BR rmdir (2)
on
.IR pathname .
.SH RETURN VALUE
On success,
.BR unlinkat ()
returns 0.
On error, \-1 is returned and
.I errno
is set to indicate the error.
.SH ERRORS
The same errors that occur for
.BR unlink (2)
and
.BR rmdir (2)
can also occur for
.BR unlinkat ().
The following additional errors can occur for
.BR unlinkat ():
.TP
.B EBADF
.I dirfd
is not a valid file descriptor.
.TP
.B EINVAL
An invalid flag value was specified in
.IR flags .
.TP
.B EISDIR
.I pathname
refers to a directory, and
.B AT_REMOVEDIR
was not specified in
.IR flags .
.TP
.B ENOTDIR
.I pathname
is relative and
.I dirfd
is a file descriptor referring to a file other than a directory.
.SH VERSIONS
.BR unlinkat ()
was added to Linux in kernel 2.6.16;
library support was added to glibc in version 2.4.
.SH CONFORMING TO
POSIX.1-2008.
A similar system call exists on Solaris.
.SH NOTES
See
.BR openat (2)
for an explanation of the need for
.BR unlinkat ().
.SH SEE ALSO
.BR openat (2),
.BR rmdir (2),
.BR unlink (2),
.BR path_resolution (7)
.so man2/unlink.2