2 .\" Copyright (c) 1995 David Hovemeyer <daveho@infocom.com>
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.
15 .\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
16 .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 .\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
19 .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 .\" $FreeBSD: src/lib/libc/sys/shmat.2,v 1.8.2.6 2001/12/14 18:34:01 ru Exp $
27 .\" $DragonFly: src/lib/libc/sys/shmat.2,v 1.2 2003/06/17 04:26:47 dillon Exp $
35 .Nd attach or detach shared memory
44 .Fn shmat "int shmid" "void *addr" "int flag"
46 .Fn shmdt "void *addr"
49 attaches the shared memory segment identified by
51 to the calling process's address space. The address where the segment
52 is attached is determined as follows:
54 .\" These are cribbed almost exactly from Stevens, _Advanced Programming in
55 .\" the UNIX Environment_.
61 is 0, the segment is attached at an address selected by the
66 is nonzero and SHM_RND is not specified in
68 the segment is attached the specified address.
72 is specified and SHM_RND is specified,
74 is rounded down to the nearest multiple of SHMLBA.
78 detaches the shared memory segment at the address specified by
80 from the calling process's address space.
84 returns the address where the segment is attached; otherwise, -1
87 is set to indicate the error.
95 No shared memory segment was found corresponding to
99 was not an acceptable address.
107 does not point to a shared memory segment.