1 .\" Copyright 2002 Andre C. Mazzone (linuxdev@karagee.com)
2 .\" May be distributed under the GNU General Public License
3 .TH IPCRM 1 "last change: 19 March 2002" "ipcrm" "Linux Programmer's Manual"
5 ipcrm \- remove a message queue, semaphore set or shared memory id
31 .RB { shm | msg | sem }
35 removes System V interprocess communication (IPC) objects
36 and associated data structures from the system.
37 In order to delete such objects, you must be superuser, or
38 the creator or owner of the object.
40 System V IPC objects are of three types: shared memory,
41 message queues, and semaphores.
42 Deletion of a message queue or semaphore object is immediate
43 (regardless of whether any process still holds an IPC
44 identifier for the object).
45 A shared memory object is only removed
46 after all currently attached processes have detached
48 the object from their virtual address space.
50 Two syntax styles are supported. The old Linux historical syntax specifies
51 a three letter keyword indicating which class of object is to be deleted,
52 followed by one or more IPC identifiers for objects of this type.
54 The SUS-compliant syntax allows the specification of
55 zero or more objects of all three types in a single command line,
56 with objects specified either by key or by identifier. (See below.)
57 Both keys and identifiers may be specified in decimal, hexadecimal
58 (specified with an initial '0x' or '0X'), or octal (specified with
64 removes the shared memory segment created with
66 after the last detach is performed.
69 removes the shared memory segment identified by
71 after the last detach is performed.
74 removes the message queue created with
78 removes the message queue identified by
82 removes the semaphore created with
86 removes the semaphore identified by
89 The details of the removes are described in
94 The identifiers and keys may be found by using
97 In its first Linux implementation, ipcrm used the deprecated syntax
100 Functionality present in other *nix implementations of ipcrm has since
101 been added, namely the ability to delete resources by key (not just
102 identifier), and to respect the same command-line syntax. For backward
103 compatibility the previous syntax is still supported.
105 .\" Andre C. Mazzone (linuxdev@karagee.com)
107 .\" Krishna Balasubramanian (balasub@cis.ohio-state.edu)
121 The ipcrm command is part of the util-linux-ng package and is available from
122 ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.