sys-utils/ipcrm.1

   1 .\" Copyright 2002 Andre C. Mazzone (linuxdev@karagee.com)
   2 .\" May be distributed under the GNU General Public License
   3 .TH IPCRM "1" "July 2014" "util-linux" "User Commands"
   4 .SH NAME
   5 ipcrm \- remove certain IPC resources
   6 .SH SYNOPSIS
   7 .B ipcrm
   8 [options]
   9 .sp
  10 .B ipcrm
  11 .RB { shm | msg | sem }
  12 .IR id ...
  13 .SH DESCRIPTION
  14 .B ipcrm
  15 removes System V inter-process communication (IPC) objects
  16 and associated data structures from the system.
  17 In order to delete such objects, you must be superuser, or
  18 the creator or owner of the object.
  19 .PP
  20 System V IPC objects are of three types: shared memory,
  21 message queues, and semaphores.
  22 Deletion of a message queue or semaphore object is immediate
  23 (regardless of whether any process still holds an IPC
  24 identifier for the object).
  25 A shared memory object is only removed
  26 after all currently attached processes have detached
  27 .RB ( shmdt (2))
  28 the object from their virtual address space.
  29 .PP
  30 Two syntax styles are supported.  The old Linux historical syntax specifies
  31 a three-letter keyword indicating which class of object is to be deleted,
  32 followed by one or more IPC identifiers for objects of this type.
  33 .PP
  34 The SUS-compliant syntax allows the specification of
  35 zero or more objects of all three types in a single command line,
  36 with objects specified either by key or by identifier (see below).
  37 Both keys and identifiers may be specified in decimal, hexadecimal
  38 (specified with an initial '0x' or '0X'), or octal (specified with
  39 an initial '0').
  40 .PP
  41 The details of the removes are described in
  42 .BR shmctl (2),
  43 .BR msgctl (2),
  44 and
  45 .BR semctl (2).
  46 The identifiers and keys can be found by using
  47 .BR ipcs (1).
  48 .SH OPTIONS
  49 .TP
  50 \fB\-a\fR, \fB\-\-all\fR [\fBshm\fR] [\fBmsg\fR] [\fBsem\fR]
  51 Remove all resources.  When an option argument is provided, the removal is
  52 performed only for the specified resource types.  \fIWarning!\fR  Do not use
  53 .B \-a
  54 if you are unsure how the software using the resources might react to missing
  55 objects.  Some programs create these resources at startup and may not have
  56 any code to deal with an unexpected disappearance.
  57 .TP
  58 .BR \-M , " \-\-shmem\-key " \fIshmkey
  59 Remove the shared memory segment created with
  60 .I shmkey
  61 after the last detach is performed.
  62 .TP
  63 .BR \-m , " \-\-shmem\-id " \fIshmid
  64 Remove the shared memory segment identified by
  65 .I shmid
  66 after the last detach is performed.
  67 .TP
  68 .BR \-Q , " \-\-queue\-key " \fImsgkey
  69 Remove the message queue created with
  70 .IR msgkey .
  71 .TP
  72 .BR \-q , " \-\-queue\-id " \fImsgid
  73 Remove the message queue identified by
  74 .IR msgid .
  75 .TP
  76 .BR \-S , " \-\-semaphore\-key " \fIsemkey
  77 Remove the semaphore created with
  78 .IR semkey .
  79 .TP
  80 .BR \-s , " \-\-semaphore\-id " \fIsemid
  81 Remove the semaphore identified by
  82 .IR semid .
  83 .TP
  84 .BR \-V , " \-\-version"
  85 Display version information and exit.
  86 .TP
  87 .BR \-h , " \-\-help"
  88 Display help text and exit.
  89 .SH NOTES
  90 In its first Linux implementation, \fBipcrm\fR used the deprecated syntax
  91 shown in the second line of the
  92 .BR SYNOPSIS .
  93 Functionality present in other *nix implementations of \fBipcrm\fR has since
  94 been added, namely the ability to delete resources by key (not just
  95 identifier), and to respect the same command-line syntax.  For backward
  96 compatibility the previous syntax is still supported.
  97 .\" .SH AUTHORS
  98 .\" Andre C. Mazzone (linuxdev@karagee.com)
  99 .\" .br
 100 .\" Krishna Balasubramanian (balasub@cis.ohio-state.edu)
 101 .SH SEE ALSO
 102 .nh
 103 .BR ipcmk (1),
 104 .BR ipcs (1),
 105 .BR msgctl (2),
 106 .BR msgget (2),
 107 .BR semctl (2),
 108 .BR semget (2),
 109 .BR shmctl (2),
 110 .BR shmdt (2),
 111 .BR shmget (2),
 112 .BR ftok (3)
 113 .SH AVAILABILITY
 114 The ipcrm command is part of the util-linux package and is available from
 115 .UR https://\:www.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
 116 Linux Kernel Archive
 117 .UE .