1 .\" $NetBSD: msgget.2,v 1.1 1995/10/16 23:49:19 jtc Exp $
3 .\" Copyright (c) 1995 Frank van der Linden
4 .\" All rights reserved.
6 .\" Redistribution and use in source and binary forms, with or without
7 .\" modification, are permitted provided that the following conditions
9 .\" 1. Redistributions of source code must retain the above copyright
10 .\" notice, this list of conditions and the following disclaimer.
11 .\" 2. Redistributions in binary form must reproduce the above copyright
12 .\" notice, this list of conditions and the following disclaimer in the
13 .\" documentation and/or other materials provided with the distribution.
14 .\" 3. All advertising materials mentioning features or use of this software
15 .\" must display the following acknowledgement:
16 .\" This product includes software developed for the NetBSD Project
17 .\" by Frank van der Linden
18 .\" 4. The name of the author may not be used to endorse or promote products
19 .\" derived from this software without specific prior written permission
21 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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23 .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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25 .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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32 .\" $FreeBSD: src/lib/libc/gen/msgget.3,v 1.7.2.5 2003/03/15 15:11:05 trhodes Exp $
47 .Fn msgget "key_t key" "int msgflg"
52 returns the message queue identifier associated with
54 A message queue identifier is a unique integer greater than zero.
56 A message queue is created if either
62 does not have a message queue identifier associated with it, and the
67 If a new message queue is created, the data structure associated with it (the
71 is initialized as follows:
77 are set to the effective uid of the calling process.
82 are set to the effective gid of the calling process.
85 is set to the lower 9 bits of
98 is set to the system wide maximum value for the number of bytes in a queue
102 is set to the current time.
105 Upon successful completion a positive message queue identifier is returned.
106 Otherwise, -1 is returned and the global variable
108 is set to indicate the error.
110 The XSI Interprocess Communication family of functions is also available
111 as an implementation in userspace.
114 daemon has to be running.
118 variable is set in a process' environment, the process and its children
119 will use the userspace implementation.
123 A message queue is already associated with
125 and the caller has no permission to access it.
133 and a message queue is already associated with
136 A new message queue could not be created because the system limit for
137 the number of message queues has been reached.
142 and no message queue associated with
151 Message queues appeared in the first release of
157 specific userspace implementation (see