NAME | SYNOPSIS | DESCRIPTION | OPTIONS | CONFORMING TO | NOTES | AUTHORS | SEE ALSO | REPORTING BUGS | AVAILABILITY |
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IPCS(1) User Commands IPCS(1)
ipcs - show information on IPC facilities
ipcs [options]
ipcs shows information on System V inter-process communication facilities. By default it shows information about all three resources: shared memory segments, message queues, and semaphore arrays.
-i, --id id Show full details on just the one resource element identified by id. This option needs to be combined with one of the three resource options: -m, -q or -s. -h, --help Display help text and exit. -V, --version Print version and exit. Resource options -m, --shmems Write information about active shared memory segments. -q, --queues Write information about active message queues. -s, --semaphores Write information about active semaphore sets. -a, --all Write information about all three resources (default). Output formats Of these options only one takes effect: the last one specified. -c, --creator Show creator and owner. -l, --limits Show resource limits. -p, --pid Show PIDs of creator and last operator. -t, --time Write time information. The time of the last control operation that changed the access permissions for all facilities, the time of the last msgsnd(2) and msgrcv(2) operations on message queues, the time of the last shmat(2) and shmdt(2) operations on shared memory, and the time of the last semop(2) operation on semaphores. -u, --summary Show status summary. Representation These affect only the -l (--limits) option. -b, --bytes Print the sizes in bytes rather than in a human-readable format. By default, the unit, sizes are expressed in, is byte, and unit prefixes are in power of 2^10 (1024). Abbreviations of symbols are exhibited truncated in order to reach a better readability, by exhibiting alone the first letter of them; examples: "1 KiB" and "1 MiB" are respectively exhibited as "1 K" and "1 M", then omitting on purpose the mention "iB", which is part of these abbreviations. --human Print sizes in human-readable format.
The Linux ipcs utility is not fully compatible to the POSIX ipcs utility. The Linux version does not support the POSIX -a, -b and -o options, but does support the -l and -u options not defined by POSIX. A portable application shall not use the -a, -b, -o, -l, and -u options.
The current implementation of ipcs obtains information about available IPC resources by parsing the files in /proc/sysvipc. Before util-linux version v2.23, an alternate mechanism was used: the IPC_STAT command of msgctl(2), semctl(2), and shmctl(2). This mechanism is also used in later util-linux versions in the case where /proc is unavailable. A limitation of the IPC_STAT mechanism is that it can only be used to retrieve information about IPC resources for which the user has read permission.
Krishna Balasubramanian <balasub@cis.ohio-state.edu>
ipcmk(1), ipcrm(1), msgrcv(2), msgsnd(2), semget(2), semop(2), shmat(2), shmdt(2), shmget(2), sysvipc(7)
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
The ipcs 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/>. This page
is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found at
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
a bug report for this manual page, send it to
util-linux@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-10.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page),
send a mail to man-pages@man7.org
util-linux 2.39.594-1e0ad 2023-07-19 IPCS(1)
Pages that refer to this page: ipcmk(1), ipcrm(1), lsipc(1), msgctl(2), semctl(2), semget(2), shmctl(2), proc_sysvipc(5), sysvipc(7)