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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | CONFORMING TO | NOTES | AUTHORS | SEE ALSO | AVAILABILITY | COLOPHON |
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
Display version information 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 sizes in bytes.
--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)
The ipcs command is part of the util-linux package and is available
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
2020-08-13. (At that time, the date of the most recent commit that
was found in the repository was 2020-08-12.) 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 July 2014 IPCS(1)
Pages that refer to this page: ipcmk(1) , ipcrm(1) , msgctl(2) , semctl(2) , semget(2) , shmctl(2) , proc(5) , procfs(5) , svipc(7) , sysvipc(7)