IPCRM(8)		  Linux Programmer's Manual		     IPCRM(8)



NAME
       ipcrm - remove a message queue, semaphore set or shared memory id

SYNOPSIS
       ipcrm [ -M key | -m id | -Q key | -q id | -S key | -s id ] ...

       deprecated usage

       ipcrm [ shm | msg | sem ] id ...

DESCRIPTION
       ipcrm  removes  System  V interprocess communication (IPC) objects and
       associated data structures from the system.  In order to	 delete	 such
       objects, you must be superuser, or the creator or owner of the object.

       System V IPC objects  are  of  three  types:  shared  memory,  message
       queues,	and  semaphores.   Deletion  of	 a message queue or semaphore
       object is immediate (regardless of whether any process still holds  an
       IPC  identifier	for  the  object).   A	shared	memory object is only
       removed	after  all  currently  attached	  processes   have   detached
       (shmdt(2)) the object from their virtual address space.

       Two  syntax  styles  are	 supported.   The old Linux historical syntax
       specifies a three letter keyword indicating which class of  object  is
       to  be deleted, followed by one or more IPC identifiers for objects of
       this type.

       The SUS-compliant syntax allows the  specification  of  zero  or	 more
       objects	of  all	 three	types  in a single command line, with objects
       specified either by key or by identifier. (See below.)  Both keys  and
       identifiers  may	 be specified in decimal, hexadecimal (specified with
       an initial '0x' or '0X'), or octal (specified with an initial '0').


OPTIONS
       -M shmkey
	      removes the shared memory segment created with shmkey after the
	      last detach is performed.

       -m shmid
	      removes the shared memory segment identified by shmid after the
	      last detach is performed.

       -Q msgkey
	      removes the message queue created with msgkey.

       -q msgid
	      removes the message queue identified by msgid.

       -S semkey
	      removes the semaphore created with semkey.

       -s semid
	      removes the semaphore identified by semid.

       The details of the removes are described in msgctl(2), shmctl(2),  and
       semctl(2).  The identifiers and keys may be found by using ipcs(8).

NOTES
       In  its	first  Linux implementation, ipcrm used the deprecated syntax
       shown in the SYNOPSIS.  Functionality present in other *nix  implemen-
       tations	of  ipcrm  has since been added, namely the ability to delete
       resources by key (not just identifier), and to respect the  same	 com-
       mand-line  syntax.  For	backward compatibility the previous syntax is
       still supported.

SEE ALSO
       ipcs(8),	 msgctl(2),  msgget(2),	 semctl(2),   semget(2),   shmctl(2),
       shmdt(2), shmget(2), ftok(3)



ipcrm			  last change: 19 March 2002		     IPCRM(8)

UNIX/Linux commands referenced on this page:

1. id
2. which
3. more
4. last