IPCRM(1)                                            Linux Programmer's Manual                                           IPCRM(1)



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  vir-
       tual 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 deci-
       mal, 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(1).

NOTES
       In  its  first  Linux  implementation,  ipcrm used the deprecated syntax shown in the SYNOPSIS.  Functionality present in
       other *nix implementations of ipcrm has since been added, namely the ability to delete resources by key (not just identi-
       fier), 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-ng package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-
       linux-ng/.



ipcrm                                              last change: 19 March 2002                                           IPCRM(1)