IPCRM(1)							   User Commands							  IPCRM(1)

NAME

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

SYNOPSIS

       ipcrm [options]
       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 speci-
       fied 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, --shmem-key shmkey
	      removes the shared memorysegment created with shmkey after the last detach is performed.

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

       -Q, --queue-key msgkey
	      removes the message queue created with msgkey.

       -q, --queue-id msgid
	      removes the message queue identified by msgid.

       -S, --semaphore-key semkey
	      removes the semaphore created with semkey.

       -s, --semaphore-id semid
	      removes the semaphore identified by semid.

       -a, --all [shm msg sem]
	      Remove  all  resources. When option argument is provided the removal is performed only to for the specified resource types. Warning!
	      Do not use -a if you are unsure how the software using resources	might  react  on  missing  objects.  Some  programs  create  these
	      resources at start up and may not have any code to deal unexpected disappearance.

       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(1).

NOTES

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

SEE ALSO

       ipcs(1), ipcmk(1), msgctl(2), msgget(2), semctl(2), semget(2), shmctl(2), shmdt(2), shmget(2), ftok(3)

AVAILABILITY

       The  ipcrm command is part of the util-linux package and is available from Linux Kernel Archive <ftp://ftp.kernel.org/pub/linux/utils/util-
       linux/>.

util-linux							  September 2011							  IPCRM(1)