.\" $Darwin$ .\" .\" Copyright (c) 1999-2002 Apple Computer, Inc. All rights reserved. .\" .\" @APPLE_LICENSE_HEADER_START@ .\" .\" The contents of this file constitute Original Code as defined in and .\" are subject to the Apple Public Source License Version 1.1 (the .\" "License"). You may not use this file except in compliance with the .\" License. Please obtain a copy of the License at .\" http://www.apple.com/publicsource and read it before using this file. .\" .\" This Original Code and all software distributed under the License are .\" distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER .\" EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, .\" INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, .\" FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the .\" License for the specific language governing rights and limitations .\" under the License. .\" .\" @APPLE_LICENSE_HEADER_END@ .\" .Dd August 31, 2006 .Dt SHM_UNLINK 2 .Os Darwin .Sh NAME .Nm shm_unlink .Nd remove shared memory object .Sh SYNOPSIS .Fd #include <sys/mman.h> .Ft int .Fn shm_unlink "const char *name" .Sh DESCRIPTION The .Fn shm_unlink function disassociates the shared memory object specified by .Fa name from that name. The resources associated with the shared memory object remain intact until the last file descriptor reference is removed, e.g., by .Xr close 2 or .Xr munmap 2 , at which point the resources are reclaimed (if no references exist at the time of the call to .Fn shm_unlink , the resources are reclaimed immediately). The name can only be reused when it is bound to a new shared memory object with a call to .Xr shm_open 2 with the .Dv O_CREAT flag. .Sh RETURN VALUES Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and .Va errno is set to indicate the error, and the named shared memory object will remain unchanged. .Sh ERRORS The .Fn shm_unlink succeeds unless: .Bl -tag -width Er .It Bq Er EACCES Permission is denied to be remove the object. .It Bq Er ENAMETOOLONG .Fa name exceeded the name size limit. This is currently .Dv PSHMNAMLEN characters (defined in .In sys/posix_shm.h ) , but this may change in the future. .It Bq Er ENOENT The named object does not exist. .El .Sh SEE ALSO .Xr close 2 , .Xr mmap 2 , .Xr munmap 2 , .Xr shm_open 2 , .Xr shmat 2 , .Xr shmctl 2 .Sh HISTORY .Fn shm_open is specified in the POSIX Realtime Extension (1003.1b-1993/1003.1i-1995).