.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" This manpage is Copyright (C) 2006, Michael Kerrisk
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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.
.\"
.\" Japanese Version Copyright (c) 2006 Yuichi SATO
.\"         all rights reserved.
.\" Translated 2006-09-27 by Yuichi SATO <ysato444@yahoo.co.jp>, LDP v2.39
.\"
.TH OPENAT 2 2006-03-06 "Linux" "Linux Programmer's Manual"
.SH ̾
openat \- ǥ쥯ȥեǥץŪʰ֤ˤե򥪡ץ󤹤
.SH 
.nf
.B #define _ATFILE_SOURCE
.B #include <fcntl.h>
.sp
.BI "int openat(int " dirfd ", const char *" pathname ", int " flags );
.BI "int openat(int " dirfd ", const char *" pathname ", int " flags \
", mode_t " mode );
.fi
.SH 
.BR openat ()
ƥॳϡ man ڡƤ㤤ʳϡ
.BR open (2)
Ʊ褦ư롣

.I pathname
ǻꤵѥ̾ХѥǤ硢
եǥץ
.I dirfd
ǻȤǥ쥯ȥ꤫Хѥ̾ȤƲᤵ
.RB ( open (2)
ǤϡХѥϸƤӽФץΥȥ󥰥ǥ쥯ȥ꤫
ХѥȤʤ)

.I pathname
ХѥǤꡢ
.I dirfd
̤
.B AT_FDCWD
Ǥ硢
.I pathname

.RB ( open (2)
Ʊ褦) ƤӽФץ
ȥ󥰥ǥ쥯ȥ꤫Хѥ̾ȤƲᤵ롣

.I pathname
ХѥǤ硢
.I dirfd
̵뤵롣
.SH ֤
硢
.BR openat ()
Ͽեǥץ֤
顼ξ硢\-1 ֤ơ
.I errno
ˤϥ顼򼨤ͤꤵ롣
.SH 顼
.BR open (2)
Ʊ顼
.BR openat ()
Ǥⵯ롣
.BR openat ()
Ǥϡ¾˰ʲΥ顼:
.TP
.B EBADF
.I dirfd
ͭʥեǥץǤʤ
.TP
.B ENOTDIR
.I pathname
Хѥǡ
.I dirfd
ǥ쥯ȥʳΥե򻲾ȤեǥץǤ롣
.SH С
.BR openat ()
 Linux ͥ 2.6.16 ɲä줿
.SH 
ΥƥॳɸŪǤϤʤ
POSIX.1 ξΥӥ˴ޤ뤳ȤƤƤ롣
Solaris ˤϡƱ褦ʥƥॳ뤬¸ߤ롣
.\" The 'at' suffix in Solaris is actually double sensed.  It
.\" primarily referred to "extended *at*tributes", which are
.\" handled by Solaris' O_XATTR flag, but was also intended
.\" to refer to the notion of "at a relative location".
.\"
.\" See the following for a discussion of the inconsistent
.\" naming of the *at() functions:
.\" http://www.opengroup.org/austin/mailarchives/ag/msg09103.html
.\" Subject: 	RE: The naming of at()s is a difficult matter
.\" From: 	Don Cragun
.\" Date: 	Tue, 14 Feb 2006 14:56:50 -0800 (PST)
.\"
.SH 
.BR openat ()
 "at" դ¾ƱͤΥƥॳϡ
2 Ĥͳˤ󶡤Ƥ롣

1 ܤͳϡ
ȥ󥰥ǥ쥯ȥʳΥǥ쥯ȥˤե뷲
.BR open (2)
ǥץ󤹤Ȥ˵ǽ붥 (race condition) 
.BR openat ()
ˤäƥץꥱ󤬲Ǥ뤿Ǥ롣
ζ֤ϡ
.BR open (2)
˻ꤵ줿ѥΥǥ쥯ȥʬ
(/ Ƕڤ줿) Ĥι (򥪡ץ󤹤) 
.BR open (2)
˸ƤӽФѴ줿˵롣
Τ褦ʶϡоݥǥ쥯ȥΥեǥץ򥪡ץ󤷡
Υեǥץ
.BR openat ()

.I dirfd
˻ꤹ뤳ȤDzǤ롣

2 ܤͳϡ
ץꥱˤäƴեǥץ () ȤȤǡ
.BR openat ()
åΤ֥ȥ󥰥ǥ쥯ȥפǤ뤿Ǥ롣
(εǽ
.IR /proc/self/fd/ dirfd
Ȥä΢Ǥ¸Ǥ뤬ޤΨŪǤϤʤ)
.SH Ϣ
.BR faccessat (2),
.BR fchmodat (2),
.BR fchownat (2),
.BR fstatat (2),
.BR futimesat (2),
.BR linkat (2),
.BR mkdirat (2),
.BR mknodat (2),
.BR open (2),
.BR readlinkat (2),
.BR renameat (2),
.BR symlinkat (2),
.BR unlinkat (2),
.BR mkfifoat (3),
.BR path_resolution (7)