2 .\" Copyright (c) 1995 David Hovemeyer <daveho@infocom.com>
4 .\" All rights reserved.
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32 .Nd attach or detach shared memory
40 .Fn shmat "int shmid" "const void *addr" "int flag"
42 .Fn shmdt "const void *addr"
47 attaches the shared memory segment identified by
49 to the calling process's address space.
50 The address where the segment
51 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 SHMLBA.
82 flag is specified and the passed
86 any existing mappings in the virtual addresses range are
87 cleared before the segment is attached.
88 If the flag is not specified,
92 and the virtual address range contains
93 some pre-existing mappings, the
100 detaches the shared memory segment at the address specified by
102 from the calling process's address space.
106 returns the address where the segment is attached; otherwise, -1
109 is set to indicate the error.
119 No shared memory segment was found corresponding to
125 was not an acceptable address.
129 cannot be used for mapping, for instance due to the amount of available
130 space being smaller than the segment size,
131 or because pre-existing mappings are in the range and no
135 Failed to attach the shared memory segment because the per-process
150 does not point to a shared memory segment.