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(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  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
       ftp://ftp.kernel.org/pub/linux/utils/util-linux/.

util-linux                                         March 2002                                           IPCRM(1)