.\" Copyright (c) 1993 Luigi P. Bai (lpb@softint.com) July 28, 1993
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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 Wed Jul 28 11:03:24 1993, Rik Faith <faith@cs.unc.edu>
.\" Modified Sun Nov 28 16:43:30 1993, Rik Faith <faith@cs.unc.edu>
.\"          with material from Giorgio Ciucci <giorgio@crcc.it>
.\" Portions Copyright 1993 Giorgio Ciucci <giorgio@crcc.it>
.\" Modified Fri Jan 31 17:24:31 1997 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified Sun Feb 18 01:59:29 2001 by Andries Brouwer <aeb@cwi.nl>
.\"
.\" 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>
.\"
.\"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 "18 Feb 2001" "Linux 2.4.1" "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 
\fBshmctl()\fP ϥ桼ͭꡦȤξꡢ
ͭ꡼νͭ (owner)롼 (group)ӵ (permission)
ꤹ뤳ȤǤ롣
\fIshmid\fP ǻꤵ줿ȤˤĤƤξ
\fIshmid_ds\fP ¤Τ֤:
.PP
.in +0.5i
.nf
struct shmid_ds {
	struct	ipc_perm shm_perm;	/* operation perms */
	int	shm_segsz;		/* size of segment (bytes) */
	time_t	shm_atime;		/* last attach time */
	time_t	shm_dtime;		/* last detach time */
	time_t	shm_ctime;		/* last change time */
	unsigned short	shm_cpid;	/* pid of creator */
	unsigned short	shm_lpid;	/* pid of last operator */
	short	shm_nattch;		/* no. of current attaches */
	/* the following are private */
	unsigned short   shm_npages;  /* size of segment (pages) */
	unsigned long   *shm_pages;   
	struct shm_desc *attaches;    /* descriptors for attaches */
};
.fi
.in -0.5i
.PP
\fIshm_perm\fP СƤ:
.PP
.in +0.5i
.nf
struct ipc_perm
{
  key_t  key;
  \fBushort uid\fP;   /* \fBowner\fP euid and egid */
  \fBushort gid\fP;
  ushort cuid;  /* creator euid and egid */
  ushort cgid;
  \fBushort mode\fP;  /* lower 9 bits of access modes */
  ushort seq;   /* sequence number */
};
.fi
.PP
ʲ \fIcmd\fP ѤǤ:
.br
.TP 12
.B IPC_STAT
ͭꡦȤ \fIbuf\fP Хåե˥ԡ뤿˻Ѥ롣
桼϶ͭꡦȤФ\fBɤ߹\fP
ǤʤФʤʤ
.TP
.B IPC_SET
桼 \fIshm_perms\fP եɤ
\fIuid\fP, \fIgid\fP, \fImode\fP С˹ԤäѹŬѤ뤿˻Ѥ롣
\fImode\fP ϲ 9 ӥåȤΤߤѤ롣
.I shm_ctime
⹹롣
桼Ͻͭ (owner)  (creator) 
ѡ桼 (super-user) ǤʤФʤʤ
.TP
.B IPC_RMID
Ȥ˲ (destroy) ޡդΤ˻Ѥ롣
ºݤˤϺǸʬΥ (detach) Ԥʤ줿 (Ϣ
.I shmid_ds
¤Τ
.I shm_nattch
Сˤʤä) ˲롣
桼ϽͭԤԤѡ桼ǤʤФʤʤ
.PP
桼ϺǽŪˤϥȤ˺줺˲\fIʤФʤʤ\fP
ǤʤС˲ʤäڡϥå (swap) ꡼˻Ĥ³롣
.PP
äơʲ \fIcmd\fP ǡ\fBѡ桼\fP
ͭꡦȤåפ뤳Ȥ˸ꡢǤǤ:
(Linux Τ)
.br
.TP 12
.B SHM_LOCK
ͭꡦȤ򥹥åפ뤳Ȥ˸롣
桼ϥåǽˤʤä˥å׵ᤷڡ
¸ߤ뤳ȤǧʤФʤʤ
.TP
.B SHM_UNLOCK
ͭꡦȤ򥹥åסȤ뤳Ȥǽˤ롣
.PP
.BR IPC_INFO ,
.BR SHM_STAT ,
.B SHM_INFO
楳
.BR ipcs (8)
ץˤäƳƤ줿񸻤ˤĤƤξ󶡤뤿˻Ѥ롣
ŪˤϤ proc ե롦ƥࡦ󥿡ե
ѤΤ˽뤫⤷ʤ
.PP
.SH ƥࡦ
.TP
.B fork()
.B fork()
θˡҥץղ (attach) 줿ͭꡦȤѾ롣
.TP
.B exec()
.B exec()
θˡƤղä줿ͭꡦȤʬΥ (detach) 
(˲Ϥʤ)
.TP
.B exit()
.B exit()
ˤơƤղä줿ͭꡦȤʬΥ (˲Ϥʤ)
.PP
.SH ֤
 0 ֤顼ξ \-1 ֤
.SH 顼
顼ξ
.B errno
ʲΤɤ줫ꤵ:
.TP 12
.B EACCES
\fBIPC_STAT\fP ׵ᤵ졢\fIshm_perm.modes\fP 
.I shmid
ؤɤ߹ߥƤʤä֤롣
.TP
.B EFAULT
.I cmd

.B IPC_SET

.B IPC_STAT
ꤵ줿
.I buf
ǻؤƤ륢ɥ쥹˥Ǥʤ
.TP
.B EINVAL
\fIshmid\fP ͭʼ̻ (identifier) Ǥʤ
\fIcmd\fP ͭʥޥɤǤʤ֤롣
.TP
.B EIDRM
\fIshmid\fP  (remove) 줿̻ҤؤƤ֤롣
.TP
.B EPERM
\fBIPC_SET\fP  \fBIPC_RMID\fP ߤ졢
桼ͭԤǤԤǤ⥹ѡ桼Ǥʤ
桼롼פ¾ԤȤƵĤƤʤ֤롣
.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 shmget (2),
.BR shmop (2)