1IPCRM(1)                         User Commands                        IPCRM(1)
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NAME

6       ipcrm - remove certain IPC resources
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SYNOPSIS

9       ipcrm [options]
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11       ipcrm {shm|msg|sem} id...
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DESCRIPTION

14       ipcrm  removes  System  V inter-process communication (IPC) objects and
15       associated data structures from the system.  In order  to  delete  such
16       objects, you must be superuser, or the creator or owner of the object.
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18       System V IPC objects are of three types: shared memory, message queues,
19       and semaphores.  Deletion of a message queue  or  semaphore  object  is
20       immediate (regardless of whether any process still holds an IPC identi‐
21       fier for the object).  A shared memory object is only removed after all
22       currently  attached  processes have detached (shmdt(2)) the object from
23       their virtual address space.
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25       Two syntax styles are supported.  The old Linux historical syntax spec‐
26       ifies  a three-letter keyword indicating which class of object is to be
27       deleted, followed by one or more IPC identifiers for  objects  of  this
28       type.
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30       The  SUS-compliant  syntax  allows  the  specification  of zero or more
31       objects of all three types in a single command line, with objects spec‐
32       ified  either by key or by identifier (see below).  Both keys and iden‐
33       tifiers may be specified in decimal,  hexadecimal  (specified  with  an
34       initial '0x' or '0X'), or octal (specified with an initial '0').
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36       The  details  of the removes are described in shmctl(2), msgctl(2), and
37       semctl(2).  The identifiers and keys can be found by using ipcs(1).
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OPTIONS

40       -a, --all [shm] [msg] [sem]
41              Remove all resources.  When an option argument is provided,  the
42              removal  is  performed  only  for  the specified resource types.
43              Warning!  Do not use -a if you are unsure how the software using
44              the  resources  might  react  to missing objects.  Some programs
45              create these resources at startup and may not have any  code  to
46              deal with an unexpected disappearance.
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48       -M, --shmem-key shmkey
49              Remove  the  shared memory segment created with shmkey after the
50              last detach is performed.
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52       -m, --shmem-id shmid
53              Remove the shared memory segment identified by shmid  after  the
54              last detach is performed.
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56       -Q, --queue-key msgkey
57              Remove the message queue created with msgkey.
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59       -q, --queue-id msgid
60              Remove the message queue identified by msgid.
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62       -S, --semaphore-key semkey
63              Remove the semaphore created with semkey.
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65       -s, --semaphore-id semid
66              Remove the semaphore identified by semid.
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68       -V, --version
69              Display version information and exit.
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71       -h, --help
72              Display help text and exit.
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NOTES

75       In  its  first  Linux  implementation, ipcrm used the deprecated syntax
76       shown in the second line of the  SYNOPSIS.   Functionality  present  in
77       other  *nix  implementations  of ipcrm has since been added, namely the
78       ability to delete resources  by  key  (not  just  identifier),  and  to
79       respect  the  same command-line syntax.  For backward compatibility the
80       previous syntax is still supported.
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SEE ALSO

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

87       The  ipcrm  command  is part of the util-linux package and is available
88       from Linux Kernel Archive ⟨https://www.kernel.org/pub/linux/utils/util-
89       linux/⟩.
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93util-linux                         July 2014                          IPCRM(1)
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