.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" This manpage is Copyright (C) 1992 Drew Eckhardt;
.\"                               1993 Michael Haardt, Ian Jackson.
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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.
.\"
.\" Modified 1993-07-21 Rik Faith (faith@cs.unc.edu)
.\" Modified 1994-08-21 by Michael Chastain (mec@shell.portal.com):
.\"   Removed note about old kernel (pre-1.1.44) using wrong id on path.
.\" Modified 1996-03-18 by Martin Schulze (joey@infodrom.north.de):
.\"   Stated more clearly how it behaves with symbolic links.
.\" Added correction due to Nick Duffek (nsd@bbc.com), aeb, 960426
.\" Modified 1996-09-07 by Michael Haardt:
.\"   Restrictions for NFS
.\" Modified 1997-09-09 by Joseph S. Myers <jsm28@cam.ac.uk>
.\" Modified 1998-01-13 by Michael Haardt:
.\"   Using access is often insecure
.\" Modified 2001-10-16 by aeb
.\" Modified 2002-04-23 by Roger Luethi <rl@hellgate.ch>
.\" Modified 2004-06-23 by Michael Kerrisk
.\"
.\" Japanese Version Copyright (c) 1997-1998 HANATAKA Shinya
.\"         all rights reserved.
.\" Translated 1997-12-17, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Modified 1998-05-11, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Updated 2001-12-14, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2002-06-17, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2005-02-23, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\"
.\"WORD:	permission		
.\"WORD:	privileges		
.\"WORD:	user			桼
.\"WORD:	file system		ե롦ƥ
.\"WORD:	object			֥
.\"WORD:	symbolic link		ܥå
.\"WORD:	refer			Ȥ
.\"WORD:	mask			ޥ
.\"WORD:	path			ѥ
.\"WORD:	effective user-ID	¸桼ID
.\"WORD:	real user-ID		¥桼ID
.\"WORD:	uid			桼 ID
.\"WORD:	gid			롼 ID
.\"WORD:	directory		ǥ쥯ȥ
.\"WORD:	call			
.\"WORD:	kernel			ͥ
.\"WORD:	memory			
.\"WORD:	dangling		Τʤ
.\"
.TH ACCESS 2 2004-06-23 "Linux" "Linux Programmer's Manual"
.SH ̾
access \- 桼ΥեФ륢å
.SH 
.nf
.B #include <unistd.h>
.sp
.BI "int access(const char *" pathname ", int " mode );
.fi
.SH 
.BR access ()

.I pathname 
Ȥ̾ĥե (ޤ¾Υե롦ƥΥ֥)
Фơץɤ߽Ф񤭹ߤƤ뤫
ե뤬¸ߤƤ뤫ʤɤΥåԤʤ
.I pathname
ܥå󥯤ʤСΥܥå󥯤λȤ
եФ륢롣

.I mode

.BR R_OK ", " W_OK ", " X_OK ", " F_OK 
ΰİʾ夫鹽ޥǤ롣

.BR R_OK ", " W_OK ", " X_OK
Ϥ줾
֥ե뤬¸ߤɤ߹ߵĤ뤫
֥ե뤬¸ߤƽ񤭹ߵĤ뤫
֥ե뤬¸ߤƼ¹ԵĤ뤫
Υå׵᤹롣
.B F_OK
ϥե뤬¸ߤ뤫ɤΤߤå褦׵᤹롣


.I pathname 
ǻꤵ줿եؤΥѥ˸ǥ쥯ȥΥ˰¸롣
ޤܥå󥯤λȤԤǽв񤦡
ǥ쥯ȥեΥˤ¸롣

åϡºݤǻѤץμ¸ (effective) ID Ǥʤ
.I " (real)"
UID  
.I " (real)"
GID ǹԤʤ롣
 set-user-ID ץǡ¹ԥ桼θ¤ꤷ䤹
뤿Ǥ롣

ӥåȤΤߤå졢եμƤϥåʤ
äơǥ쥯ȥֽ꤬񤭹߲ǽפȤʤäϡǥ쥯ȥ
ե뤳ȤǽʤȤ̣ΤǤꡢǥ쥯ȥ
եȤƽ񤭹ळȤǽʤ櫓ǤϤʤ
Ʊͤ DOS Υեϡּ¹ԲǽפȽǤ뤬
.BR execve (2)
ϼԤ

ץŬڤʸ¤äƤ硢
եμ¹ԵĥӥåȤҤȤĤ⥻åȤƤʤƤ⡢
.B X_OK
֤⤢롣
.SH ֤
(Ƥ׵ᤵ줿Ĥ줿)֤롣
顼ξ (ʤȤĤ
.I mode
׵ᤵ줿Ĥʤä䡢¾Υ顼)
\-1 ֤졢
.I errno
Ŭڤꤵ롣
.SH 顼
.BR access ()
ϰʲξ˼Ԥ롣
.TP
.B EACCES
׵ᤵ줿
Υե뼫Ȥ˵ݤ줿
.I pathname
ػޤǥǥ쥯ȥΤ줫Ф븡
(search permission) ʤä
.RB ( path_resolution (2)
⻲ȤΤ)
.TP
.B ELOOP
.I pathname
褹ݤܥå󥯤¿᤮롣
.TP
.B ENAMETOOLONG
.I pathname
Ĺ᤮롣
.TP
.B ENOENT
.I pathname
Υǥ쥯ȥʬϥǽǤä
ե뤬¸ߤʤΤʤ (dangling) ܥå󥯤
ʤäƤ롣
.TP
.B ENOTDIR
.I pathname
Υǥ쥯ȥʬºݤˤϥǥ쥯ȥǤʤ
.TP
.B EROFS
ɤ߹ (read-only) Υե롦ƥФƽ񤭹ߵĤ
׵ᤷ
.PP
.BR access ()
ϰʲͳˤ꼺Ԥ뤳Ȥ롣
.TP
.B EFAULT
.I pathname
ǽʥɥ쥹֤γؤƤ롣
.TP
.B EINVAL
.I mode
ͤꤵ줿
.TP
.B EIO
I/O 顼ȯ
.TP
.B ENOMEM
ͥ˽ʬʥ꤬ʤ
.TP
.B ETXTBSY
¹ΥեФƽ񤭹ߤ׵ᤷ
.SH 
.BR access ()
׵ᤵ줿̤Τ줫Υå˼Ԥˤϡ
Ȥ¾μ̤ΥåȤƤ⥨顼֤
.PP
.BR access ()
ϡ UID ޥåԥ󥰤Ѥ NFS ե롦ƥǤ
ǽʤ⤷ʤʤʤ UID Υޥåԥ󥰤ϥС
Ԥʤ졢Υå򤹤륯饤ȤˤϸʤǤ롣
.PP
桼㤨
.BR open (2)
ˤ륢ǽɤ(ºݤ˹Ԥ)
.BR access ()
ȤäƥåΤϡƥۡθˤʤ롣
ʤʤå򤷤Ƥ
ºݤ˥եΥץ򤹤֤ûֳ֤ѤǤ뤫Ǥ롣
.SH 
SVr4, POSIX.1-2001, 4.3BSD
.SH Ϣ
.BR chmod (2),
.BR chown (2),
.BR faccessat (2),
.BR open (2),
.BR path_resolution (2),
.BR setgid (2),
.BR setuid (2),
.BR stat (2)