## NAME

ipcs - show information on IPC facilities

## SYNOPSIS

ipcs [options]

## DESCRIPTION

ipcs shows information on the inter-process communication facilities for which the calling process has read access. 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() and msgrcv() operations on message queues, the time of the last shmat() and shmdt() operations on shared memory, and the time of the last semop() 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.

## SEE ALSO

ipcrm (1), ipcmk (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 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, -land -u options.

## AUTHOR

Krishna Balasubramanian

## AVAILABILITY

The ipcs command is part of the util-linux package and is available from

Linux Kernel Archive