.\" Hey Emacs! This file is -*- nroff -*- source.
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.\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu)
.\"
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.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
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.\" Permission is granted to copy and distribute modified versions of this
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.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
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.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
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.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
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.\" Modified Thu Oct 31 12:04:29 1996 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified, 27 May 2004, Michael Kerrisk <mtk.manpages@gmail.com>
.\"     Added notes on capability requirements
.\" 2008-05-03, mtk, expanded and rewrote parts of DESCRIPTION and RETURN
.\"     VALUE, made style of page more consistent with man-pages style.
.\"
.\" Japanese Version Copyright (c) 1997 HANATAKA Shinya
.\"         all rights reserved.
.\" Translated 1997-02-22, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Updated 2001-02-10, Yuichi SATO <sato@complex.eng.hokudai.ac.jp>
.\" Updated & Modified 2004-12-30, Yuichi SATO <ysato444@yahoo.co.jp>
.\" Updated 2008-08-04, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v3.05
.\"
.\"WORD:	group			롼
.\"WORD:	access			
.\"WORD:	process			ץ
.\"WORD:	super user		ѡ桼
.\"WORD:	supplementary group	롼
.\"
.TH GETGROUPS 2 2008-06-03 "Linux" "Linux Programmer's Manual"
.SH ̾
getgroups, setgroups \- 롼 ID ΥꥹȤ/ꤹ
.SH 
.B #include <sys/types.h>
.br
.B #include <unistd.h>
.sp
.BI "int getgroups(int " size ", gid_t " list []);
.sp
.B #include <grp.h>
.sp
.BI "int setgroups(size_t " size ", const gid_t *" list );
.sp
.in -4n
glibc εǽޥ׷
.RB ( feature_test_macros (7)
):
.in
.sp
.BR setgroups ():
_BSD_SOURCE
.SH 
.PP
.BR getgroups ()
ϸƤӽФץ롼 (supplementary group) ID 
.I list
֤
.I size
ˤϡ
.I list
ˤ껲ȤХåե˳ǼǤǤκꤹ٤Ǥ롣
ƤӽФץ
.I size
Ĥ¿롼פΥФξˤϡ顼Ȥʤ롣
δؿƤӽФץμ¸롼 ID 
֤ꥹȤ˴ޤޤ뤫ɤϵꤵƤʤ
(äơץꥱ
.BR getegid (2)
ƤӽФη̤ͤɲá٤Ǥ)

.I size
 0 ʤС
.I list
ϽʤΥץ롼 ID ι׿֤롣
ȤȤǡʹߤ
.BR getgroups ()
θƤӽФɬפȤʤưŪƥХåե
.I list
Υ򡢸ƤӽФꤹ뤳ȤǤ롣
.PP
.BR setgroups ()
ϡƤӽФץ롼 ID ꤹ롣
Ŭڤø (Linux Ǥ
.B CAP_SETGID
ѥӥƥ (capability)) ɬפǤ롣
.I size
ˤϡ
.I list
ˤ껲ȤХåե˳Ǽ줿롼 ID οꤹ롣
.SH ֤
.BR getgroups ()
ϡ롼 ID ο֤
顼ξ \-1 ֤
.I errno
Ŭڤꤹ롣

.BR setgroups ()
ϡ 0 ֤
顼ξ \-1 ֤
.I errno
Ŭڤꤹ롣
.SH 顼
.TP
.B EFAULT
.I list
ʥɥ쥹Ǥ롣
.PP
.BR getgroups ()
ϡ嵭˲äưʲΥ顼ǼԤǽ롣
.TP
.B EINVAL
.I size
롼 ID ο꾮 0 Ǥʤ
.PP
.BR setgroups ()
ϡ嵭˲äưʲΥ顼ǼԤǽ롣
.TP
.B EINVAL
.I size

.B NGROUPS_MAX
礭
.RB ( NGROUPS_MAX
 Linux 2.6.4 Ǥ 32Linux 2.6.4 ʹߤǤ 65536)
.TP
.B ENOMEM
­
.TP
.B EPERM
ƤӽФץʬøäƤʤ
.SH 
SVr4, 4.3BSD.
.BR getgroups ()
ؿ POSIX.1-2001 ˽򤷤Ƥ롣
.BR setgroups ()
øɬפȤ뤿ᡢPOSIX.1-2001 ˽äƤʤ
.SH 
ץϡ¸롼 ID ˲ä
.B NGROUPS_MAX
ޤǤ롼 ID ĤȤǤ롣
롼 ID νϿƥץѾ졢
.BR execve (2)
ݻ롣

롼 ID κ
.BR sysconf (3)
ȤäưʲΤ褦ˤĴ٤뤳ȤǤ:
.nf

    long ngroups_max;
    ngroups_max = sysconf(_SC_NGROUPS_MAX);

.fi
.BR getgroups ()
֤ͤκͤϡͤ 1 礭ͤ礭ʤ뤳ȤϤʤ
.SH Ϣ
.BR getgid (2),
.BR setgid (2),
.BR getgrouplist (3),
.BR initgroups (3),
.BR capabilities (7),
.BR credentials (7)