ipcrm(1) — Linux manual page


IPCRM(1)                        User Commands                       IPCRM(1)

NAME         top

       ipcrm - remove certain IPC resources

SYNOPSIS         top

       ipcrm [options]

       ipcrm {shm|msg|sem} id...

DESCRIPTION         top

       ipcrm removes System V inter-process 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

       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').

       The details of the removes are described in shmctl(2), msgctl(2), and
       semctl(2).  The identifiers and keys can be found by using ipcs(1).

OPTIONS         top

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

       -M, --shmem-key shmkey
              Remove the shared memory segment created with shmkey after the
              last detach is performed.

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

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

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

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

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

       -V, --version
              Display version information and exit.

       -h, --help
              Display help text and exit.

NOTES         top

       In its first Linux implementation, ipcrm used the deprecated syntax
       shown in the second line of 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         top

       ipcmk(1), ipcs(1), msgctl(2), msgget(2), semctl(2), semget(2),
       shmctl(2), shmdt(2), shmget(2), ftok(3), sysvipc(7)

AVAILABILITY         top

       The ipcrm command is part of the util-linux package and is available
       from Linux Kernel Archive 

COLOPHON         top

       This page is part of the util-linux (a random collection of Linux
       utilities) project.  Information about the project can be found at 
       ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩.  If you have a
       bug report for this manual page, send it to
       util-linux@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
       2020-09-18.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-09-15.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
       there is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

util-linux                        July 2014                         IPCRM(1)

Pages that refer to this page: ipcmk(1)ipcs(1)lsipc(1)pcp-ipcs(1)svipc(7)sysvipc(7)