ipcs(1) - man - phpman

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⚡ TLDR: ipcs (tldr-pages)

Show information about the usage of XSI IPC facilities: shared memory segments, message queues, and semaphore arrays.

Show information about all the IPC
ipcs -a
Show information about active shared memory segments, message queues or sempahore sets
ipcs {{m|-q|-s}}
Show information on maximum allowable size in bytes
ipcs -b
Show creator's user name and group name for all IPC facilities
ipcs -c
Show the pID of the last operators for all IPC facilities
ipcs -p
Show access times for all IPC facilities
ipcs -t
Show outstanding usage for active message queues, and shared memory segments
ipcs -o

IPCS(1)                                     User Commands                                    IPCS(1)



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, --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.

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 <balasub AT cis.edu>

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 at https://github.com/karelzak/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/>.



util-linux 2.37.2                            2021-06-02                                      IPCS(1)