.\" Copyright (c) 1993 Luigi P. Bai (lpb@softint.com) July 28, 1993
.\" Portions Copyright 1993 Giorgio Ciucci <giorgio@crcc.it>
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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 1993-07-28, Rik Faith <faith@cs.unc.edu>
.\" Modified 1993-11-28, Giorgio Ciucci <giorgio@crcc.it>
.\" Modified 1997-01-31, Eric S. Raymond <esr@thyrsus.com>
.\" Modified 2001-02-18, Andries Brouwer <aeb@cwi.nl>
.\" Modified 2002-01-05, 2004-05-27, 2004-06-17,
.\"    Michael Kerrisk <mtk-manpages@gmx.net>
.\" Modified 2004-10-11, aeb
.\" Modified, Nov 2004, Michael Kerrisk <mtk-manpages@gmx.net>
.\"	Language and formatting clean-ups
.\"	Updated shmid_ds structure definitions
.\"	Added information on SHM_DEST and SHM_LOCKED flags
.\"	Noted that CAP_IPC_LOCK is not required for SHM_UNLOCK 
.\"		since kernel 2.6.9
.\" Modified, 2004-11-25, mtk, notes on 2.6.9 RLIMIT_MEMLOCK changes
.\"
.\" Japanese Version Copyright (c) 1997 HANATAKA Shinya
.\"         all rights reserved.
.\" Translated Sat Mar  1 16:49:09 JST 1997
.\"         by HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Updated & Modified Wed Jun 13 20:53:52 JST 2001
.\"         by Yuichi SATO <ysato@h4.dion.ne.jp>
.\" Updated & Modified Wed Jan  5 03:20:25 JST 2005
.\"         by Yuichi SATO <ysato444@yahoo.co.jp>
.\"
.\"WORD:	shared memory		ͭ
.\"WORD:	segment			
.\"WORD:	owner			ͭ
.\"WORD:	group			롼
.\"WORD:	creator			
.\"WORD:	super-user		ѡ桼
.\"WORD:	detach			ʬΥ
.\"WORD:	attach			ղ
.\"WORD:	swap			å
.\"WORD:	identifier		̻
.\"WORD:	member			С
.\"
.TH SHMCTL 2 2004-11-10 "Linux 2.6.9" "Linux Programmer's Manual"
.SH ̾
shmctl \- ͭ (shared memory) 椹
.SH 
.ad l
.B #include <sys/ipc.h>
.sp
.B #include <sys/shm.h>
.sp
.BI "int shmctl(int " shmid ", int " cmd ", struct shmid_ds *" buf );
.ad b
.SH 
.BR shmctl ()
ˤꡢƤӽФ϶ͭꡦȤξꡢ
Ȥνͭ (owner)롼 (group) (permission) ꤷꡢ
Ȥ˲ (destroy) Ǥ롣
.PP
.I buf
 \fIshmid_ds\fP ¤ΤؤΥݥ󥿤Ǥ롣
ι¤Τ <sys/shm.h> ǰʲΤ褦Ƥ
.PP
.in +4n
.nf
struct shmid_ds {
    struct ipc_perm shm_perm;    /* ͭȵ */
    size_t          shm_segsz;   /* ȤΥ (Х) */
    time_t          shm_atime;   /* Ǹղ (attach) λ */
    time_t          shm_dtime;   /* ǸʬΥ (detach) λ */
    time_t          shm_ctime;   /* ǸѹԤ줿 */
    pid_t           shm_cpid;    /*  (creator)  PID */
    pid_t           shm_lpid;    /* Ǹ stmat()/shmdt()  PID */
    shmatt_t        shm_nattch;  /* ղäƤ */
    ...
};
.fi
.in -4n
.PP
.I ipc_perm
¤Τ <sys/ipc.h> ǰʲΤ褦Ƥ
(Ĵ줿եɤ
.B IPC_SET
ȤäǽǤ):
.PP
.in +4n
.nf
struct ipc_perm {
    key_t key;            /* shmget() Ϳ륭 */
    uid_t \fBuid\fP;            /* ͭԤμ¸ UID */
    gid_t \fBgid\fP;            /* ͭԤμ¸ GID */
    uid_t cuid;           /* Ԥμ¸ UID */
    gid_t cgid;           /* Ԥμ¸ GID */
    unsigned short \fBmode\fP;  /* \fB\fP + SHM_DEST 
                             SHM_LOCKED ե饰 */
    unsigned short seq;   /* ֹ */
};
.fi
.in -4n
.PP
.I cmd
Ȥͭͤϰʲ̤:
.br
.TP 12
.B IPC_STAT
.I shmid
˴ϢŤ줿ͥǡ¤Τξ
\fIbuf\fP ǻؤ줿
.I shmid_ds
¤Τ˥ԡ롣
ƤӽФ϶ͭꡦȤФ
ɤ߹ߵĤʤФʤʤ
.TP
.B IPC_SET
.I arg.buf
ˤäƻؤ
.I shmid_ds
¤ΤΤĤΥСͤ
ζͭꡦȤ˴ϢŤ줿ͥǡ¤Τ˽񤭹ߡ
.I shm_ctime
С⹹롣
ʲΥեɤѹǤ롣
\fIshm_perms.uid\fP, \fIshm_perms.gid\fP,
\fIshm_perms.mode\fP (κDz 9 ӥå)
ƤӽФץμ¸ UID ͭ
.RI ( shm_perm.uid )
ޤϺ
.RI ( shm_perm.cuid )
Ȱפ뤫ƤӽФøʤФʤʤ
.TP
.B IPC_RMID
Ȥ˲ѤߤΥޡդ롣
ȤϡºݤˤϺǸץȤʬΥ (Ϣ
.I shmid_ds
¤Τ
.I shm_nattch
С 0 ˤʤä) ǤΤ˲롣
ƤӽФϽͭԤԤǤ뤫øʤФʤʤ
Ȥ˲Υޡդȡ
Ϣǡ¤Τˤ
.I shm_perm.mode
եɤ (ɸǤϤʤ)
.B SHM_DEST
ե饰ꤵ롣
Υǡ¤Τ
.B IPC_STAT
Ǽ롣
.PP
ƤӽФϺǽŪˤϥȤ˺줺˲\fIʤФʤʤ\fP
ǤʤСե (fault) 줿ڡ
꤫å (swap) ˻Ĥ³롣
.SS "Linux ˤɲ"
øĸƤӽФϡʲ \fIcmd\fP ͤˤꡢ
ͭꡦȤåפ뤳Ȥ˸ꡢǤǤ:
.br
.TP 12
.B SHM_LOCK
ͭꡦȤ򥹥åפ뤳Ȥ˸롣
åǽˤʤä塢ƤӽФϡ
¸ߤ뤳Ȥ׵ᤵ줿ƤΥڡեȤʤФʤʤ
Ȥåȡ
Ϣǡ¤Τˤ
.I shm_perm.mode
եɤ (ɸŪǤϤʤ)
.B SHM_LOCKED
ե饰ꤵ롣
Υǡ¤Τ
.B IPC_STAT
Ǽ롣
.TP
.B SHM_UNLOCK
ȤΥååסȤ뤳Ȥǽˤ롣
.PP
.BR IPC_INFO ,
.BR SHM_STAT ,
.B SHM_INFO
楳
.BR ipcs (8)
ץˤäƳƤ줿񸻤ˤĤƤξ󶡤뤿˻Ѥ롣
.SH ֤
 0 ֤
顼ξ \-1 ֤
.I errno
Ŭڤꤹ롣
.SH 顼
.TP 11
.B EACCES

\fBIPC_STAT\fP ޤ \fBSHM_STAT\fP ׵ᤵ졢
\fIshm_perm.modes\fP 
.I shmid
ؤɤ߹ߥƤ餺
ĸƤӽФץ
.BR CAP_IPC_OWNER
ѥӥƥ (capability) äƤʤ
.TP
.B EFAULT
.I cmd

.B IPC_SET

.B IPC_STAT
ꤵ줿
.I buf
ǻؤƤ륢ɥ쥹˥Ǥʤ
.TP
.B EIDRM
\fIshmid\fP  (remove) 줿̻ (identifier) ؤƤ롣
.TP
.B EINVAL
\fIshmid\fP ͭʼ̻ҤǤʤ
\fIcmd\fP ͭʥޥɤǤʤ
.TP
.B ENOMEM
(2.6.9 ʹߤΥͥˤ)
.B SHM_LOCK
ꤵ졢
åͽΥȤΥ
(å붦ͭꡦȤιץХȿ) 
ƤӽФץμ¥桼 ID ˤĤƤ¤Ķ
¤
.BR RLIMIT_MEMLOCK
եȻ¤
.RB ( setrlimit (2)
򻲾)
.TP
.B EOVERFLOW
\fBIPC_STAT\fP ߤ졢gid  uid ͤ
.IR buf 
ǻؼ빽¤Τ˳Ǽˤ礭᤮롣
.TP
.B EPERM
\fBIPC_SET\fP  \fBIPC_RMID\fP ߤ졢
ƤӽФץμ¸桼 ID 
.RI ( shm_perm.cuid )
Ǥͭ
.RI ( shm_perm.uid )
Ǥʤץøʤ (Linux Ǥ
.B CAP_SYS_ADMIN
ѥӥƥʤ)

ޤ (2.6.9 Υͥ)
.B SHM_LOCK
ޤ
.B SHM_UNLOCK
ꤵƤ뤬ץøʤ
(Linux Ǥ
.B CAP_IPC_LOCK
ѥӥƥʤ)
(Linux 2.6.9 ʹߤǤϡ
.BR RLIMIT_MEMLOCK
 0 ǸƤӽФøʤˤ⡢Υ顼롣)
.SH 
\fI¤ shmid_ds\fP ¿Υեɤϡ
Linux 2.2 ǤûäLinux 2.4 ǤĹʤä
ˤϡglibc-2.1.91 ʹߤδĶ
ƥѥ뤹нʬǤ롣
ͥϿθƤӽФȸŤθƤӽФ
.I cmd
 IPC_64 ե饰Ƕ̤롣
.SH 
SVr4, SVID.  SVr4 ˤ¾ EINVAL, ENOENT, ENOSPC, ENOMEM, 
EEXIST 顼ˤĤƤεҤ롣
SVr4  SVID ˤ EIDRM 顼ˤĤƤεҤϤʤ
.SH Ϣ
.BR mlock (2),
.BR setrlimit (2),
.BR shmget (2),
.BR shmop (2),
.BR capabilities (7)