ipcs(1) - f39

1IPCS(1)                          User Commands                         IPCS(1)
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NAME

6       ipcs - show information on IPC facilities
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SYNOPSIS

9       ipcs [options]
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DESCRIPTION

12       ipcs shows information on System V inter-process communication
13       facilities. By default it shows information about all three resources:
14       shared memory segments, message queues, and semaphore arrays.
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OPTIONS

17       -i, --id id
18           Show full details on just the one resource element identified by
19           id. This option needs to be combined with one of the three resource
20           options: -m, -q or -s.
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22       -h, --help
23           Display help text and exit.
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25       -V, --version
26           Print version and exit.
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28   Resource options
29       -m, --shmems
30           Write information about active shared memory segments.
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32       -q, --queues
33           Write information about active message queues.
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35       -s, --semaphores
36           Write information about active semaphore sets.
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38       -a, --all
39           Write information about all three resources (default).
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41   Output formats
42       Of these options only one takes effect: the last one specified.
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44       -c, --creator
45           Show creator and owner.
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47       -l, --limits
48           Show resource limits.
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50       -p, --pid
51           Show PIDs of creator and last operator.
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53       -t, --time
54           Write time information. The time of the last control operation that
55           changed the access permissions for all facilities, the time of the
56           last msgsnd(2) and msgrcv(2) operations on message queues, the time
57           of the last shmat(2) and shmdt(2) operations on shared memory, and
58           the time of the last semop(2) operation on semaphores.
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60       -u, --summary
61           Show status summary.
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63   Representation
64       These affect only the -l (--limits) option.
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66       -b, --bytes
67           Print the sizes in bytes rather than in a human-readable format.
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69           By default, the unit, sizes are expressed in, is byte, and unit
70           prefixes are in power of 2^10 (1024). Abbreviations of symbols are
71           exhibited truncated in order to reach a better readability, by
72           exhibiting alone the first letter of them; examples: "1 KiB" and "1
73           MiB" are respectively exhibited as "1 K" and "1 M", then omitting
74           on purpose the mention "iB", which is part of these abbreviations.
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76       --human
77           Print sizes in human-readable format.
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CONFORMING TO

80       The Linux ipcs utility is not fully compatible to the POSIX ipcs
81       utility. The Linux version does not support the POSIX -a, -b and -o
82       options, but does support the -l and -u options not defined by POSIX. A
83       portable application shall not use the -a, -b, -o, -l, and -u options.
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NOTES

86       The current implementation of ipcs obtains information about available
87       IPC resources by parsing the files in /proc/sysvipc. Before util-linux
88       version v2.23, an alternate mechanism was used: the IPC_STAT command of
89       msgctl(2), semctl(2), and shmctl(2). This mechanism is also used in
90       later util-linux versions in the case where /proc is unavailable. A
91       limitation of the IPC_STAT mechanism is that it can only be used to
92       retrieve information about IPC resources for which the user has read
93       permission.
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AUTHORS

96       Krishna Balasubramanian <balasub@cis.ohio-state.edu>
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REPORTING BUGS

103       For bug reports, use the issue tracker at
104       https://github.com/util-linux/util-linux/issues.
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AVAILABILITY

107       The ipcs command is part of the util-linux package which can be
108       downloaded from Linux Kernel Archive
109       <https://www.kernel.org/pub/linux/utils/util-linux/>.
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113util-linux 2.39.2                 2023-06-14                           IPCS(1)