ipcrm

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
       implementations 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(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)