NAME
ipcs - show information on IPC facilities
SYNOPSIS
ipcs [options]
DESCRIPTION
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.
OPTIONS
-i, --idid
-h, --help
-V, --version
Resource options
-m, --shmems
-q, --queues
-s, --semaphores
-a, --all
Output formats
Of these options only one takes effect: the last one specified.
-c, --creator
-l, --limits
-p, --pid
-t, --time
-u, --summary
Representation
These affect only the -l (--limits) option.
-b, --bytes
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
CONFORMING TO
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.
NOTES
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.
AUTHORS
Krishna Balasubramanian <[email protected]>
SEE ALSO
ipcmk(1), ipcrm(1), msgrcv(2), msgsnd(2), semget(2), semop(2), shmat(2), shmdt(2), shmget(2), sysvipc(7)
REPORTING BUGS
For bug reports, use the issue tracker <https://github.com/util-linux/util-linux/issues>.
AVAILABILITY
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/>.