2 .\" Copyright (c) 1995 David Hovemeyer <daveho@infocom.com>
4 .\" All rights reserved.
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34 .Nd attach or detach shared memory
42 .Fn shmat "int shmid" "const void *addr" "int flag"
44 .Fn shmdt "const void *addr"
49 attaches the shared memory segment identified by
51 to the calling process's address space.
52 The address where the segment
53 is attached is determined as follows:
55 .\" These are cribbed almost exactly from Stevens, _Advanced Programming in
56 .\" the UNIX Environment_.
62 is 0, the segment is attached at an address selected by the
71 the segment is attached the specified address.
79 is rounded down to the nearest multiple of SHMLBA.
84 flag is specified and the passed
88 any existing mappings in the virtual addresses range are
89 cleared before the segment is attached.
90 If the flag is not specified,
94 and the virtual address range contains
95 some pre-existing mappings, the
102 detaches the shared memory segment at the address specified by
104 from the calling process's address space.
108 returns the address where the segment is attached; otherwise, -1
111 is set to indicate the error.
121 No shared memory segment was found corresponding to
127 was not an acceptable address.
131 cannot be used for mapping, for instance due to the amount of available
132 space being smaller than the segment size,
133 or because pre-existing mappings are in the range and no
137 Failed to attach the shared memory segment because the per-process
152 does not point to a shared memory segment.