ipcs(1)



IPCS(1)                          User Commands                         IPCS(1)

NAME
       ipcs - show information on IPC facilities

SYNOPSIS
       ipcs [options]

DESCRIPTION
       ipcs  shows  information on 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  re-
              source 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.

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 re-
       trieve information about IPC resources for which the user has read per-
       mission.

SEE ALSO
       ipcmk(1),   ipcrm(1),   msgrcv(2),   msgsnd(2),   semget(2),  semop(2),
       shmat(2), shmdt(2), shmget(2)

CONFORMING TO
       The Linux ipcs utility is not fully compatible to the POSIX ipcs  util-
       ity.   The  Linux  version does not support the POSIX -a, -b and -o op-
       tions, 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.

AUTHOR
       Krishna Balasubramanian <balasub@cis.ohio-state.edu>

AVAILABILITY
       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/>.

util-linux                         July 2014                           IPCS(1)

Man(1) output converted with man2html
list of all man pages