NAME

       ipcrm - remove certain IPC resources

SYNOPSIS

       ipcrm [options]

       ipcrm [shm|msg|sem] ID ...

DESCRIPTION

       ipcrm removes POSIX and 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
       object.

       POSIX and 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), shm_unlink(3), msgctl(2), mq_unlink(3), semctl(2),
       and sem_unlink(3). The identifiers and keys can be found by using lsipc(1) or ipcs(1).

OPTIONS

       -a, --all [shm] [pshm] [msg] [pmsg] [sem] [psem]
           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.

       -x, --posix-shmem name
           Remove the POSIX shared memory segment created with name.

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

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

       -y, --posix-mqueue name
           Remove the POSIX message queue created with name.

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

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

       -z, --posix-semaphore name
           Remove the POSIX named semaphore created with name.

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

       -V, --version
           Display version and exit.

NOTES

       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

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

REPORTING BUGS

       For bug reports, use the issue tracker <https://github.com/util-linux/util-linux/issues>.

AVAILABILITY

       The ipcrm command is part of the util-linux package which can be downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.41                                    2025-02-26                                           IPCRM(1)