IPCS(1) | General Commands Manual | IPCS(1)

# NAME

`ipcs` — report System V interprocess communication facilities status

# SYNOPSIS

`ipcs` | [`-abcMmopQqSsTt`] [`-C` core] [`-N` system]

# DESCRIPTION

The `ipcs` program provides information on System V interprocess communication (IPC) facilities on the system.

The options are as follows:

`-a`
  Show the maximum amount of information possible when displaying active semaphores, message queues, and shared memory segments. (This is shorthand for specifying the `-b`, `-c`, `-o`, `-p`, and `-t` options.)
`-b`
  Show the maximum allowed sizes for active semaphores, message queues, and shared memory segments. The “maximum allowed size” is the maximum number of bytes in a message on a message queue, the size of a shared memory segment, or the number of semaphores in a set of semaphores.
`-C` core
  Extract values associated with the name list from the specified core instead of the running kernel.
`-c`
  Show the creator's name and group for active semaphores, message queues, and shared memory segments.
`-M`
  Display system information about shared memory.
`-m`
  Display information about active shared memory segments.
`-N` system
  Extract the name list from the specified system instead of the running kernel.
`-o`
  Show outstanding usage for active message queues, and shared memory segments. The “outstanding usage” is the number of messages in a message queue, or the number of processes attached to a shared memory segment.
`-p`
  Show the process ID information for active semaphores, message queues, and shared memory segments. The “process ID information” is the last process to send a message to or receive a message from a message queue, the process that created a semaphore, or the last process to attach or detach a shared memory segment.
`-Q`
  Display system information about messages queues.
`-q`
  Display information about active message queues.
`-S`
  Display system information about semaphores.
`-s`
  Display information about active semaphores.
`-T`
  Display system information about shared memory, message queues and semaphores.
`-t`
  Show access times for active semaphores, message queues, and shared memory segments. The access times is the time of the last control operation on an IPC object, the last send or receive of a message, the last attach or detach of a shared memory segment, or the last operation on a semaphore.

If none of the `-M`, `-m`, `-Q`, `-q`, `-S`, or `-s` options are specified, information about all active IPC facilities is listed.

# RESTRICTIONS

System data structures may change while `ipcs` is running; the output of `ipcs` is not guaranteed to be consistent.

# EXIT STATUS

The `ipcs` utility exits 0 on success, and >0 if an error occurs.

# SEE ALSO

ipcrm(1)

# STANDARDS

The `ipcs` utility is compliant with the X/Open System Interfaces option of the IEEE Std 1003.1-2008 (“POSIX.1”) specification.

The flags [`-CMNQST`] are extensions to that specification.

# AUTHORS

Thorsten Lockert <tholo@sigmasoft.com>

# BUGS

This manual page is woefully incomplete, because it does not at all attempt to explain the information printed by `ipcs`.

March 22, 2014 | Debian