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[linuxjm/jm.git] / manual / LDP_man-pages / draft / man2 / chown.2

.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
.\" and Copyright (c) 1998 Andries Brouwer (aeb@cwi.nl)
.\" and Copyright (c) 2007, 2008 Michael Kerrisk <mtk.manpages@gmail.com>
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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 by Michael Haardt <michael@moria.de>
.\" Modified 1993-07-21 by Rik Faith <faith@cs.unc.edu>
.\" Modified 1996-07-09 by Andries Brouwer <aeb@cwi.nl>
.\" Modified 1996-11-06 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 1997-05-18 by Michael Haardt <michael@cantor.informatik.rwth-aachen.de>
.\" Modified 2004-06-23 by Michael Kerrisk <mtk.manpages@gmail.com>
.\" 2007-07-08, mtk, added an example program; updated SYNOPSIS
.\" 2008-05-08, mtk, Describe rules governing ownership of new files
.\"     (bsdgroups versus sysvgroups, and the effect of the parent
.\"     directory's set-group-ID permission bit).
.\"
.\" Japanese Version Copyright (c) 1996 Yosiaki Yanagihara
.\"         all rights reserved.
.\" Translated 1996-06-24, Yosiaki Yanagihara <yosiaki@bsd2.kbnes.nec.co.jp>
.\" Modified 1998-05-11, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Modified 2004-02-29, Yuichi SATO <ysato444@yahoo.co.jp>
.\" Updated & Modified Wed Dec 29 06:48:16 JST 2004 by Yuichi SATO
.\" Updated 2007-09-04, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v2.64
.\" Updated 2008-08-09, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v3.05
.\"
.TH CHOWN 2 2008-06-16 "Linux" "Linux Programmer's Manual"
.\"O .SH NAME
.SH ̾Á°
.\"O chown, fchown, lchown \- change ownership of a file
chown, fchown, lchown \- ¥Õ¥¡¥¤¥ë¤Î½êÍ­¼Ô¤òÊѹ¹¤¹¤ë
.\"O .SH SYNOPSIS
.SH ½ñ¼°
.B #include <unistd.h>
.sp
.BI "int chown(const char *" path ", uid_t " owner ", gid_t " group );
.br
.BI "int fchown(int " fd ", uid_t " owner ", gid_t " group );
.br
.BI "int lchown(const char *" path ", uid_t " owner ", gid_t " group );
.sp
.in -4n
.\"O Feature Test Macro Requirements for glibc (see
.\"O .BR feature_test_macros (7)):
glibc ¸þ¤±¤Îµ¡Ç½¸¡ºº¥Þ¥¯¥í¤ÎÍ×·ï
.RB ( feature_test_macros (7)
»²¾È):
.in
.sp
.BR fchown (),
.BR lchown ():
_BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500
.\"O .SH DESCRIPTION
.SH ÀâÌÀ
.\"O These system calls change the owner and group of a file.
.\"O The differ only in how the file is specified:
¤³¤ì¤é¤Î¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ï¡¢¥Õ¥¡¥¤¥ë¤Î½êÍ­¼Ô (owner) ¤È¥°¥ë¡¼¥×¤òÊѹ¹¤¹¤ë¡£
¥·¥¹¥Æ¥à¥³¡¼¥ë´Ö¤Î°ã¤¤¤Ï¡¢¥Õ¥¡¥¤¥ë¤Î»ØÄê¤Î»ÅÊý¤À¤±¤Ç¤¢¤ë¡£
.IP * 2
.\"O .BR chown ()
.\"O changes the ownership of the file specified by
.\"O .IR path ,
.\"O which is dereferenced if it is a symbolic link.
.BR chown ()
¤Ï
.I path
¤Ç»ØÄꤵ¤ì¤¿¥Õ¥¡¥¤¥ë¤Î½êÍ­¸¢¤òÊѹ¹¤¹¤ë¡£
.I path
¤¬¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤Î¾ì¹ç¤Ï¡¢¥ê¥ó¥¯¤ÎŸ³«¤¬¹Ô¤ï¤ì¤ë¡£
.IP *
.\"O .BR fchown ()
.\"O changes the ownership of the file referred to by the open file descriptor
.\"O .IR fd .
.BR fchown ()
¤Ï¥ª¡¼¥×¥ó¤µ¤ì¤¿¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿
.I fd
¤Ë¤è¤ê»²¾È¤µ¤ì¤ë¥Õ¥¡¥¤¥ë¤Î½êÍ­¸¢¤òÊѹ¹¤¹¤ë¡£
.IP *
.\"O .BR lchown ()
.\"O is like
.\"O .BR chown (),
.\"O but does not dereference symbolic links.
.BR lchown ()
¤Ï
.BR chown ()
¤ÈƱ¤¸¤À¤¬¡¢¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤òŸ³«¤·¤Ê¤¤ÅÀ¤¬°Û¤Ê¤ë¡£
.PP
.\"O Only a privileged process (Linux: one with the
.\"O .B CAP_CHOWN
.\"O capability) may change the owner of a file.
Æø¢¤ò»ý¤Ä¥×¥í¥»¥¹ (Linux ¤Ç¤Ï
.B CAP_CHOWN
¥±¡¼¥Ñ¥Ó¥ê¥Æ¥£ (capability) ¤ò»ý¤Ä¥×¥í¥»¥¹) ¤À¤±¤¬
¥Õ¥¡¥¤¥ë¤Î½êÍ­¼Ô¤òÊѹ¹¤Ç¤­¤ë¡£
.\"O The owner of a file may change the group of the file
.\"O to any group of which that owner is a member.
¥Õ¥¡¥¤¥ë¤Î½êÍ­¼Ô¤Ï¡¢¤½¤Î½êÍ­¼Ô¤¬Â°¤·¤Æ¤¤¤ë¥°¥ë¡¼¥×¤Î¤¤¤º¤ì¤«¤Ë
¥Õ¥¡¥¤¥ë¤Î¥°¥ë¡¼¥×¤òÊѹ¹¤¹¤ë¤³¤È¤¬¤Ç¤­¤ë¡£
.\"O A privileged process (Linux: with
.\"O .BR CAP_CHOWN )
.\"O may change the group arbitrarily.
Æø¢ (Linux ¤Ç¤Ï
.BR CAP_CHOWN )
¤ò»ý¤Ä¥×¥í¥»¥¹¤Ï¡¢Ç¤°Õ¤Î¥°¥ë¡¼¥×¤ËÊѹ¹¤Ç¤­¤ë¡£

.\"O If the
.\"O .I owner
.\"O or
.\"O .I group
.\"O is specified as \-1, then that ID is not changed.
.I owner
¤Þ¤¿¤Ï
.I group
¤Ë \-1 ¤¬»ØÄꤵ¤ì¤¿¾ì¹ç¡¢¤½¤ì¤é¤Î ID ¤ÏÊѹ¹¤µ¤ì¤Ê¤¤¡£

.\"O When the owner or group of an executable file are
.\"O changed by an unprivileged user the
.\"O .B S_ISUID
.\"O and
.\"O .B S_ISGID
.\"O mode bits are cleared.
.\"O POSIX does not specify whether
.\"O this also should happen when root does the
.\"O .BR chown ();
ÈóÆø¢¥æ¡¼¥¶¡¼¤Ë¤è¤ê¼Â¹Ô¥Õ¥¡¥¤¥ë¤Î½êÍ­¼Ô¤Þ¤¿¤Ï¥°¥ë¡¼¥×¤¬
Êѹ¹¤µ¤ì¤¿¾ì¹ç¤Ï
.B S_ISUID
¤È
.B ISGID
¥â¡¼¥É¥Ó¥Ã¥È¤Ï¥¯¥ê¥¢¤µ¤ì¤ë¡£
POSIX ¤Ï¤³¤ÎÆ°ºî¤ä¥ë¡¼¥È¤¬
.BR chown ()
¤ò¹Ô¤Ê¤Ã¤¿¾ì¹ç¤Ë¤Ä¤¤¤Æ¤ÏÆä˻ØÄꤵ¤ì¤Æ¤¤¤Ê¤¤¡£
.\"O the Linux behavior depends on the kernel version.
Linux ¤Ë¤ª¤±¤ëÆ°ºî¤Ï¥«¡¼¥Í¥ë¤Î¥Ð¡¼¥¸¥ç¥ó¤Ë°Í¸¤¹¤ë¡£
.\"O .\" In Linux 2.0 kernels, superuser was like everyone else
.\"O .\" In 2.2, up to 2.2.12, these bits were not cleared for superuser.
.\"O .\" Since 2.2.13, superuser is once more like everyone else.
.\" Linux 2.0 ¥«¡¼¥Í¥ë¤Ç¤Ï¡¢¥¹¡¼¥Ñ¡¼¡¦¥æ¡¼¥¶¡¼¤Ç¤ÎÆ°ºî¤Ï
.\" ¾¤Î¥æ¡¼¥¶¡¼¤Î¾ì¹ç¤ÈƱ¤¸¤Ç¤¢¤Ã¤¿¡£
.\" 2.2 ¤Ç¤Ï¡¢2.2.12 ¤Þ¤Ç¤Ï¡¢¥¹¡¼¥Ñ¡¼¡¦¥æ¡¼¥¶¡¼¤Î¾ì¹ç¤Ë¤Ï
.\" ¤³¤ì¤é¤Î¥Ó¥Ã¥È¤Ï¥¯¥ê¥¢¤µ¤ì¤Ê¤¯¤Ê¤Ã¤¿¡£
.\" 2.2.13 °Ê¹ß¤Ç¤Ï¡¢¥¹¡¼¥Ñ¡¼¡¦¥æ¡¼¥¶¡¼¤Ç¤ÎÆ°ºî¤Ï
.\" ºÆ¤Ó¾¤Î¥æ¡¼¥¶¡¼¤Î¾ì¹ç¤ÈƱ¤¸¤Ë¤Ê¤Ã¤¿¡£
.\"O In case of a non-group-executable file (i.e., one for which the
.\"O .B S_IXGRP
.\"O bit is not set) the
.\"O .B S_ISGID
.\"O bit indicates mandatory locking, and is not cleared by a
.\"O .BR chown ().
È󥰥롼¥×¼Â¹Ô¥Õ¥¡¥¤¥ë
.RB ( S_IXGRP
¥Ó¥Ã¥È¤¬ÀßÄꤵ¤ì¤Æ¤¤¤Ê¤¤¥Õ¥¡¥¤¥ë) ¤Î¾ì¹ç¤Ë¤Ï
.B S_ISGID
¥Ó¥Ã¥È¤Ï¶¯À©¥í¥Ã¥¯ (mandatory locking) ¤ò°ÕÌ£¤·¤Æ¤¤¤ë¡£
¤½¤·¤Æ¤½¤ì¤Ï
.BR chown ()
¤Ç¤Ï¥¯¥ê¥¢¤Ç¤­¤Ê¤¤¡£
.\"O .SH "RETURN VALUE"
.SH ÊÖ¤êÃÍ
.\"O On success, zero is returned.
.\"O On error, \-1 is returned, and
.\"O .I errno
.\"O is set appropriately.
À®¸ù¤¹¤ë¤È¡¢0 ¤òÊÖ¤¹¡£
¼ºÇÔ¤¹¤ë¤È¡¢\-1 ¤òÊÖ¤·¡¢
.I errno
¤ËŬÀÚ¤ÊÃͤòÀßÄꤹ¤ë¡£
.\"O .SH ERRORS
.SH ¥¨¥é¡¼
.\"O Depending on the file system, other errors can be returned.
.\"O The more general errors for
.\"O .BR chown ()
.\"O are listed below.
¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Ë¤è¤Ã¤Æ¤Ï¾¤Î¥¨¥é¡¼¤¬ÊÖ¤µ¤ì¤ë»ö¤¬¤¢¤ë¡£
.B chmod
¤Ç°ìÈÌŪ¤Ê¥¨¥é¡¼¤ò°Ê²¼¤Ëµó¤²¤ë¡£
.TP
.B EACCES
.\"O Search permission is denied on a component of the path prefix.
.\"O (See also
.\"O .BR path_resolution (7).)
.I path
¤Î¹½À®Í×ÁǤ˸¡º÷µö²Ä (search permission) ¤¬¤Ê¤¤
.RB ( path_resolution (7)
¤â»²¾È)¡£
.TP
.B EFAULT
.\"O .I path
.\"O points outside your accessible address space.
.I path
¤¬³ä¤êÅö¤Æ¤é¤ì¤¿¥¢¥É¥ì¥¹¶õ´Ö³°¤ò»Ø¤·¤Æ¤¤¤ë¡£
.TP
.B ELOOP
.\"O Too many symbolic links were encountered in resolving
.\"O .IR path .
.I path
¤ò²ò·è¤¹¤ëºÝ¤ËÁø¶ø¤·¤¿¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤¬Â¿²á¤®¤ë¡£
.TP
.B ENAMETOOLONG
.\"O .I path
.\"O is too long.
.I path
¤¬Ä¹²á¤®¤ë¡£
.TP
.B ENOENT
.\"O The file does not exist.
¥Õ¥¡¥¤¥ë¤¬Â¸ºß¤·¤Ê¤¤¡£
.TP
.B ENOMEM
.\"O Insufficient kernel memory was available.
¥«¡¼¥Í¥ë¤Ë½½Ê¬¤Ê¥á¥â¥ê¤¬¤Ê¤¤¡£
.TP
.B ENOTDIR
.\"O A component of the path prefix is not a directory.
.I path
¤Î¹½À®Í×ÁǤ¬¥Ç¥£¥ì¥¯¥È¥ê¤Ç¤Ê¤¤¡£
.TP
.B EPERM
.\"O The calling process did not have the required permissions
.\"O (see above) to change owner and/or group.
¸Æ¤Ó½Ð¤·¤¿¥×¥í¥»¥¹¤Ë½êÍ­¼Ô¤Þ¤¿¤Ï¥°¥ë¡¼¥× (¤â¤·¤¯¤Ï¤½¤ÎξÊý) ¤òÊѹ¹¤¹¤ë¤¿¤á¤Ë
Í׵ᤵ¤ì¤ëµö²Ä (¾åµ­¤ò»²¾È) ¤¬¤Ê¤¤¡£
.TP
.B EROFS
.\"O The named file resides on a read-only file system.
»ØÄꤷ¤¿¥Õ¥¡¥¤¥ë¤¬Æɤ߹þ¤ßÀìÍÑ (read-only) ¤Î¥Õ¥¡¥¤¥ë¡¦¥·¥¹¥Æ¥à¾å¤Ë¤¢¤ë¡£
.PP
.\"O The general errors for
.\"O .BR fchown ()
.\"O are listed below:
.BR fchown ()
¤Ç°ìÈÌŪ¤Ê¥¨¥é¡¼¤ò°Ê²¼¤Ëµó¤²¤ë:
.TP
.B EBADF
.\"O The descriptor is not valid.
¥Ç¥£¥¹¥¯¥ê¥×¥¿¡¼¤¬Í­¸ú¤Ç¤Ê¤¤¡£
.TP
.B EIO
.\"O A low-level I/O error occurred while modifying the inode.
i ¥Î¡¼¥É (inode) ¤òÊѹ¹¤¹¤ëºÝ¤ËÄã¥ì¥Ù¥ë I/O ¥¨¥é¡¼¤¬È¯À¸¤·¤¿¡£
.TP
.B ENOENT
.\"O See above.
¾åµ­¤ò»²¾È¡£
.TP
.B EPERM
.\"O See above.
¾åµ­¤ò»²¾È¡£
.TP
.B EROFS
.\"O See above.
¾åµ­¤ò»²¾È¡£
.\"O .SH "CONFORMING TO"
.SH ½àµò
4.4BSD, SVr4, POSIX.1-2001.

.\"O The 4.4BSD version can only be
.\"O used by the superuser (that is, ordinary users cannot give away files).
4.4BSD ÈǤǤϥ¹¡¼¥Ñ¡¼¡¦¥æ¡¼¥¶¡¼¤Î¤ß¤¬»ÈÍѤǤ­¤ë
(¤Ä¤Þ¤ê¡¢ÉáÄ̤Υ桼¥¶¡¼¤Ï¥Õ¥¡¥¤¥ë¤ò¼êÊü¤¹¤³¤È¤Ï¤Ç¤­¤Ê¤¤)¡£
.\"O .\" chown():
.\"O .\" SVr4 documents EINVAL, EINTR, ENOLINK and EMULTIHOP returns, but no
.\"O .\" ENOMEM.  POSIX.1 does not document ENOMEM or ELOOP error conditions.
.\" chown():
.\" SVr4 ¤Ë¤Ï EINVAL, EINTR, ENOLINK, EMULTIHOP ¤òÊÖ¤¹¤Èµ­ºÜ¤µ¤ì¤Æ¤¤¤ë¤¬¡¢
.\" ENOMEM ¤Ï¤Ê¤¤¡£
.\" POSIX.1 ¤Ë¤Ï ENOMEM, ELOOP ¤Ë¤Ä¤¤¤Æµ­ºÜ¤Ï¤Ê¤¤¡£
.\"O .\" fchown():
.\"O .\" SVr4 documents additional EINVAL, EIO, EINTR, and ENOLINK
.\"O .\" error conditions.
.\" fchown():
.\" SVr4 ¤Ë¤Ï¾¤Ë EINVAL, EIO, EINTR, ENOLINK ¥¨¥é¡¼¾õÂ֤ˤĤ¤¤Æ¤Îµ­ºÜ¤¬¤¢¤ë¡£
.\"O .SH NOTES
.SH Ãí°Õ
.\"O When a new file is created (by, for example,
.\"O .BR open (2)
.\"O or
.\"O .BR mkdir (2)),
.\"O its owner is made the same as the file system user ID of the
.\"O creating process.
.RB ( open (2)
¤ä
.BR mkdir (2)
¤Ê¤É¤Ë¤è¤ê) ¿·¤·¤¤¥Õ¥¡¥¤¥ë¤¬ºîÀ®¤µ¤ì¤ë¤È¤­¡¢
¤½¤Î½êÍ­¼Ô¤Ï¸Æ¤Ó½Ð¤·¤¿¥×¥í¥»¥¹¤Î¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¡¦¥æ¡¼¥¶ ID ¤È
Ʊ¤¸¤ËÀßÄꤵ¤ì¤ë¡£
.\"O The group of the file depends on a range of factors,
.\"O including the type of file system,
.\"O the options used to mount the file system,
.\"O and whether or not the set-group-ID permission bit is enabled
.\"O on the parent directory.
¤½¤Î¥Õ¥¡¥¤¥ë¤Î¥°¥ë¡¼¥×¤Ï¤¤¤¯¤Ä¤«¤ÎÍ×°ø¤Ë¤è¤ê·èÄꤵ¤ì¤ë¡£
¤½¤ÎÍ×°ø¤È¤·¤Æ¤Ï¡¢
¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Î¼ïÎà¡¢¤½¤Î¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Î¥Þ¥¦¥ó¥È»þ¤Ë
»ÈÍѤµ¤ì¤¿¥ª¥×¥·¥ç¥ó¡¢¿Æ¥Ç¥£¥ì¥¯¥È¥ê¤Ç set-group-ID µö²Ä¥Ó¥Ã¥È¤¬
Í­¸ú¤Ë¤Ê¤Ã¤Æ¤¤¤ë¤É¤¦¤«¡¢¤¬¤¢¤ë¡£
.\"O If the file system supports the
.\"O .I "\-o\ grpid"
.\"O (or, synonymously
.\"O .IR "\-o\ bsdgroups" )
.\"O and
.\"O .I "\-o\ nogrpid"
.\"O (or, synonymously
.\"O .IR "\-o\ sysvgroups" )
.\"O .BR mount (8)
.\"O options, then the rules are as follows:
¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤¬
.BR mount (8)
¥ª¥×¥·¥ç¥ó¤Î
.I "\-o\ grpid"
.RI ( "\-o\ bsdgroups"
¤âƱµÁ¸ì) ¤È
.I "\-o\ nogrpid"
.RI ( "\-o sysvgroups"
¤âƱµÁ¸ì) ¤ËÂбþ¤·¤Æ¤¤¤ë¾ì¹ç¡¢¥ë¡¼¥ë¤Ï°Ê²¼¤ÎÄ̤ê¤È¤Ê¤ë¡£
.IP * 2
.\"O If the file system is mounted with
.\"O .IR "\-o\ grpid" ,
.\"O then the group of a new file is made
.\"O the same as that of the parent directory.
¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤¬
.I "\-o\ grpid"
ÉÕ¤­¤Ç¥Þ¥¦¥ó¥È¤µ¤ì¤Æ¤¤¤ë¾ì¹ç¡¢¿·¤·¤¤¥Õ¥¡¥¤¥ë¤Î¥°¥ë¡¼¥×¤Ï
¿Æ¥Ç¥£¥ì¥¯¥È¥ê¤Î¥°¥ë¡¼¥×¤ÈƱ¤¸¤Ë¤Ê¤ë¡£
.IP *
.\"O If the file system is mounted with
.\"O .IR "\-o\ nogrpid"
.\"O and the set-group-ID bit is disabled on the parent directory,
.\"O then the group of a new file is made the same as the
.\"O process's file system GID.
¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤¬
.I "\-o\ nogrpid"
ÉÕ¤­¤Ç¥Þ¥¦¥ó¥È¤µ¤ì¤Æ¤ª¤ê¡¢¿Æ¥Ç¥£¥ì¥¯¥È¥ê¤Ç¤Ï set-group-ID ¥Ó¥Ã¥È¤¬
̵¸ú¤Ë¤Ê¤Ã¤Æ¤¤¤ë¾ì¹ç¡¢¿·¤·¤¤¥Õ¥¡¥¤¥ë¤Î¥°¥ë¡¼¥×¤Ï
¥×¥í¥»¥¹¤Î¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à GID ¤ÈƱ¤¸¤Ë¤Ê¤ë¡£
.IP *
.\"O If the file system is mounted with
.\"O .IR "\-o\ nogrpid"
.\"O and the set-group-ID bit is enabled on the parent directory,
.\"O then the group of a new file is made
.\"O the same as that of the parent directory.
¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤¬
.I "\-o\ nogrpid"
ÉÕ¤­¤Ç¥Þ¥¦¥ó¥È¤µ¤ì¤Æ¤ª¤ê¡¢¿Æ¥Ç¥£¥ì¥¯¥È¥ê¤Ç¤Ï set-group-ID ¥Ó¥Ã¥È¤¬
Í­¸ú¤Ë¤Ê¤Ã¤Æ¤¤¤ë¾ì¹ç¡¢¿·¤·¤¤¥Õ¥¡¥¤¥ë¤Î¥°¥ë¡¼¥×¤Ï
¿Æ¥Ç¥£¥ì¥¯¥È¥ê¤Î¥°¥ë¡¼¥×¤ÈƱ¤¸¤Ë¤Ê¤ë¡£
.PP
.\"O As at Linux 2.6.25,
.\"O the
.\"O .IR "\-o\ grpid"
.\"O and
.\"O .IR "\-o\ nogrpid"
.\"O mount options are supported by ext2, ext3, ext4, and XFS.
.\"O File systems that don't support these mount options follow the
.\"O .IR "\-o\ nogrpid"
.\"O rules.
Linux 2.6.25 ¤Ç¤Ï¡¢¥Þ¥¦¥ó¥È¥ª¥×¥·¥ç¥ó
.I "\-o\ grpid"
¤È
.I "\-o\ nogrpid"
¤ËÂбþ¤·¤Æ¤¤¤ë¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Ï
ext2, ext3, ext4, XFS ¤Ç¤¢¤ë¡£
¤³¤ì¤é¤Î¥Þ¥¦¥ó¥È¥ª¥×¥·¥ç¥ó¤ËÂбþ¤·¤Æ¤¤¤Ê¤¤¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Ç¤Ï¡¢
.I "\-o\ nogrpid"
¤Ë´Ø¤¹¤ë¥ë¡¼¥ë¤¬Å¬ÍѤµ¤ì¤ë¡£
.PP
.\"O The
.\"O .BR chown ()
.\"O semantics are deliberately violated on NFS file systems
.\"O which have UID mapping enabled.
.\"O Additionally, the semantics of all system
.\"O calls which access the file contents are violated, because
.\"O .BR chown ()
.\"O may cause immediate access revocation on already open files.
.\"O Client side
.\"O caching may lead to a delay between the time where ownership have
.\"O been changed to allow access for a user and the time where the file can
.\"O actually be accessed by the user on other clients.
.BR chown ()
Êý¼°¤Ï UID ¥Þ¥Ã¥Ô¥ó¥°¤ò»ÈÍѤ·¤¿
NFS ¥Õ¥¡¥¤¥ë¡¦¥·¥¹¥Æ¥à¤ò¿¯³²¤¹¤ë¡£
¤µ¤é¤Ë¥Õ¥¡¥¤¥ë¤ÎÆâÍƤ˥¢¥¯¥»¥¹¤¹¤ëÁ´¤Æ¤Î¥·¥¹¥Æ¥à¡¦¥³¡¼¥ë¤ò¿¯³²¤¹¤ë¡£
¤³¤ì¤Ï
.BR chown ()
¤¬´û¤Ë¥ª¡¼¥×¥ó¤µ¤ì¤¿¥Õ¥¡¥¤¥ë¤ËÂФ¹¤ë
¥¢¥¯¥»¥¹¤ò¤¿¤À¤Á¤Ë¼è¤ê¾Ã¤¹¤³¤È¤Ë¤è¤ë¡£
¥¯¥é¥¤¥¢¥ó¥È¦¤Î¥­¥ã¥Ã¥·¥å¤Ë¤è¤ê½êÍ­¸¢¤¬Êѹ¹¤µ¤ì¤Æ
¥æ¡¼¥¶¡¼¤Î¥¢¥¯¥»¥¹¤¬µö¤·¤¿»þÅÀ¤È¡¢¼ÂºÝ¤Ë¾¤Î¥¯¥é¥¤¥¢¥ó¥È¤Ç¥æ¡¼¥¶¡¼¤Ë¤è¤Ã¤Æ
¥Õ¥¡¥¤¥ë¤Ë¥¢¥¯¥»¥¹¤Ç¤­¤ë»þÅÀ¤È¤Î´Ö¤Ë»þ´Öº¹¤¬¤¢¤ë¤«¤â¤·¤ì¤Ê¤¤¡£

.\"O In versions of Linux prior to 2.1.81 (and distinct from 2.1.46),
.\"O .BR chown ()
.\"O did not follow symbolic links.
Linux ¤Î 2.1.81 ¤è¤êÁ°¤Î¥Ð¡¼¥¸¥ç¥ó (ÆÃ¤Ë 2.1.46 °ÊÁ°) ¤Ç¤Ï¡¢
.BR chown ()
¤Ï¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤òÄÉÀפ·¤Ê¤¤¡£
.\"O Since Linux 2.1.81,
.\"O .BR chown ()
.\"O does follow symbolic links, and there is a new system call
.\"O .BR lchown ()
.\"O that does not follow symbolic links.
Linux 2.1.81 °Ê¹ß¤Ç¤Ï
.BR chown ()
¤Ï¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤òÄÉÀפ·¡¢¿·¤¿¤Ê¥·¥¹¥Æ¥à¡¦¥³¡¼¥ë
.BR lchown ()
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.\"O Since Linux 2.1.86, this new call (that has the same semantics
.\"O as the old
.\"O .BR chown ())
.\"O has got the same syscall number, and
.\"O .BR chown ()
.\"O got the newly introduced number.
Linux 2.1.86 °Ê¹ß¤Ç¤Ï¤³¤Î¿·¤·¤¤¥³¡¼¥ë (¸Å¤¤
.BR chown ()
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.BR chown ()
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.\"O .SH EXAMPLE
.SH Îã
.PP
.\"O The following program changes the ownership of the file named in
.\"O its second command-line argument to the value specified in its
.\"O first command-line argument.
.\"O The new owner can be specified either as a numeric user ID,
.\"O or as a username (which is converted to a user ID by using
.\"O .BR getpwnam (3)
.\"O to perform a lookup in the system password file).
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.BR getpwnam (3)
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.nf

#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int
main(int argc, char *argv[])
{
    uid_t uid;
    struct passwd *pwd;
    char *endptr;

    if (argc != 3 || argv[1][0] == \(aq\\0\(aq) {
        fprintf(stderr, "%s <owner> <file>\\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    uid = strtol(argv[1], &endptr, 10);  /* Allow a numeric string */

    if (*endptr != \(aq\\0\(aq) {         /* Was not pure numeric string */
        pwd = getpwnam(argv[1]);   /* Try getting UID for username */
        if (pwd == NULL) {
            perror("getpwnam");
            exit(EXIT_FAILURE);
        }

        uid = pwd\->pw_uid;
    }

    if (chown(argv[2], uid, \-1) == \-1) {
        perror("chown");
        exit(EXIT_FAILURE);
    } /* if */

    exit(EXIT_SUCCESS);
} /* main */
.fi
.\"O .SH "SEE ALSO"
.SH ´ØÏ¢¹àÌÜ
.BR chmod (2),
.BR fchownat (2),
.BR flock (2),
.BR path_resolution (7),
.BR symlink (7)