2 .\" Copyright (c) 1995 David Hovemeyer <daveho@infocom.com>
4 .\" All rights reserved.
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26 .\" $FreeBSD: src/lib/libc/sys/shmat.2,v 1.8.2.6 2001/12/14 18:34:01 ru Exp $
34 .Nd attach or detach shared memory
43 .Fn shmat "int shmid" "const void *addr" "int flag"
45 .Fn shmdt "const void *addr"
48 attaches the shared memory segment identified by
50 to the calling process's address space.
51 The address where the segment is attached is determined as follows:
53 .\" These are cribbed almost exactly from Stevens, _Advanced Programming in
54 .\" the UNIX Environment_.
60 is 0, the segment is attached at an address selected by the
69 the segment is attached the specified address.
77 is rounded down to the nearest multiple of
82 detaches the shared memory segment at the address specified by
84 from the calling process's address space.
88 returns the address where the segment is attached; otherwise, -1
91 is set to indicate the error.
95 The XSI Interprocess Communication family of functions is also available
96 as an implementation in userspace.
99 daemon has to be running.
103 variable is set in a process' environment, the process and its children
104 will use the userspace implementation.
110 No shared memory segment was found corresponding to
114 was not an acceptable address.
122 does not point to a shared memory segment.
131 specific userspace implementation (see