+++ /dev/null
-.\" Copyright 1993 Giorgio Ciucci <giorgio@crcc.it>
-.\"
-.\" %%%LICENSE_START(VERBATIM)
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-.\" 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-.\" manual page may be incorrect or out-of-date.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.
-.\" %%%LICENSE_END
-.\"
-.\" Added correction due to Nick Duffek <nsd@bbc.com>, aeb, 960426
-.\" Modified Wed Nov 6 04:00:31 1996 by Eric S. Raymond <esr@thyrsus.com>
-.\" Modified, 8 Jan 2003, Michael Kerrisk, <mtk.manpages@gmail.com>
-.\" Removed EIDRM from errors - that can't happen...
-.\" Modified, 27 May 2004, Michael Kerrisk <mtk.manpages@gmail.com>
-.\" Added notes on capability requirements
-.\" Modified, 11 Nov 2004, Michael Kerrisk <mtk.manpages@gmail.com>
-.\" Language and formatting clean-ups
-.\" Added notes on /proc files
-.\"
-.TH MSGGET 2 2014-04-30 "Linux" "Linux Programmer's Manual"
-.SH NAME
-msgget \- get a System V message queue identifier
-.SH SYNOPSIS
-.nf
-.B #include <sys/types.h>
-.B #include <sys/ipc.h>
-.B #include <sys/msg.h>
-
-.BI "int msgget(key_t " key ", int " msgflg );
-.fi
-.SH DESCRIPTION
-The
-.BR msgget ()
-system call returns the System\ V message queue identifier associated
-with the value of the
-.I key
-argument.
-A new message queue is created if
-.I key
-has the value
-.B IPC_PRIVATE
-or
-.I key
-isn't
-.BR IPC_PRIVATE ,
-no message queue with the given key
-.I key
-exists, and
-.B IPC_CREAT
-is specified in
-.IR msgflg .
-.PP
-If
-.I msgflg
-specifies both
-.B IPC_CREAT
-and
-.B IPC_EXCL
-and a message queue already exists for
-.IR key ,
-then
-.BR msgget ()
-fails with
-.I errno
-set to
-.BR EEXIST .
-(This is analogous to the effect of the combination
-.B O_CREAT | O_EXCL
-for
-.BR open (2).)
-.PP
-Upon creation, the least significant bits of the argument
-.I msgflg
-define the permissions of the message queue.
-These permission bits have the same format and semantics
-as the permissions specified for the
-.I mode
-argument of
-.BR open (2).
-(The execute permissions are not used.)
-.PP
-If a new message queue is created,
-then its associated data structure
-.I msqid_ds
-(see
-.BR msgctl (2))
-is initialized as follows:
-.IP
-.I msg_perm.cuid
-and
-.I msg_perm.uid
-are set to the effective user ID of the calling process.
-.IP
-.I msg_perm.cgid
-and
-.I msg_perm.gid
-are set to the effective group ID of the calling process.
-.IP
-The least significant 9 bits of
-.I msg_perm.mode
-are set to the least significant 9 bits of
-.IR msgflg .
-.IP
-.IR msg_qnum ,
-.IR msg_lspid ,
-.IR msg_lrpid ,
-.IR msg_stime ,
-and
-.I msg_rtime
-are set to 0.
-.IP
-.I msg_ctime
-is set to the current time.
-.IP
-.I msg_qbytes
-is set to the system limit
-.BR MSGMNB .
-.PP
-If the message queue already exists the permissions are
-verified, and a check is made to see if it is marked for
-destruction.
-.SH RETURN VALUE
-If successful, the return value will be the message queue identifier (a
-nonnegative integer), otherwise \-1
-with
-.I errno
-indicating the error.
-.SH ERRORS
-On failure,
-.I errno
-is set to one of the following values:
-.TP
-.B EACCES
-A message queue exists for
-.IR key ,
-but the calling process does not have permission to access the queue,
-and does not have the
-.B CAP_IPC_OWNER
-capability.
-.TP
-.B EEXIST
-.B IPC_CREAT
-and
-.BR IPC_EXCL
-were specified in
-.IR msgflg ,
-but a message queue already exists for
-.IR key .
-.TP
-.B ENOENT
-No message queue exists for
-.I key
-and
-.I msgflg
-did not specify
-.BR IPC_CREAT .
-.TP
-.B ENOMEM
-A message queue has to be created but the system does not have enough
-memory for the new data structure.
-.TP
-.B ENOSPC
-A message queue has to be created but the system limit for the maximum
-number of message queues
-.RB ( MSGMNI )
-would be exceeded.
-.SH CONFORMING TO
-SVr4, POSIX.1-2001.
-.SH NOTES
-The inclusion of
-.I <sys/types.h>
-and
-.I <sys/ipc.h>
-isn't required on Linux or by any version of POSIX.
-However,
-some old implementations required the inclusion of these header files,
-and the SVID also documented their inclusion.
-Applications intended to be portable to such old systems may need
-to include these header files.
-.\" Like Linux, the FreeBSD man pages still document
-.\" the inclusion of these header files.
-
-.B IPC_PRIVATE
-isn't a flag field but a
-.I key_t
-type.
-If this special value is used for
-.IR key ,
-the system call ignores everything but the least significant 9 bits of
-.I msgflg
-and creates a new message queue (on success).
-.PP
-The following is a system limit on message queue resources affecting a
-.BR msgget ()
-call:
-.TP
-.B MSGMNI
-System-wide limit on the number of message queues: policy
-dependent
-(on Linux, this limit can be read and modified via
-.IR /proc/sys/kernel/msgmni ).
-.SS Linux notes
-Until version 2.3.20, Linux would return
-.B EIDRM
-for a
-.BR msgget ()
-on a message queue scheduled for deletion.
-.SH BUGS
-The name choice
-.B IPC_PRIVATE
-was perhaps unfortunate,
-.B IPC_NEW
-would more clearly show its function.
-.SH SEE ALSO
-.BR msgctl (2),
-.BR msgrcv (2),
-.BR msgsnd (2),
-.BR ftok (3),
-.BR capabilities (7),
-.BR mq_overview (7),
-.BR svipc (7)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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