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IPCS(1) BSD General Commands Manual IPCS(1)
NAME
ipcs -- report System V interprocess communication facilities status
SYNOPSIS
ipcs [-abcmopqstMQSTy] [-C core] [-N system] [-u user]
DESCRIPTION
The ipcs utility 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 Show the creator's name and group for active semaphores, message queues, and shared memory segments.
-m Display information about active shared memory segments.
-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 information about active message queues.
-s Display information about active semaphores.
-t Show access times for active semaphores, message queues, and shared memory segments. The access times is the time of the last con-
trol 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.
-C core
Extract values associated with the name list from the specified core instead of the default /dev/kmem. Implies -y.
-M Display system information about shared memory.
-N system
Extract the name list from the specified system instead of the default /boot/kernel/kernel. Implies -y.
-Q Display system information about messages queues.
-S Display system information about semaphores.
-T Display system information about shared memory, message queues and semaphores.
-y Use the kvm(3) interface instead of the sysctl(3) interface to extract the required information. If ipcs is to operate on the run-
ning system, using kvm(3) will require read privileges to /dev/kmem.
-u user
Display information about IPC mechanisms owned by user. User specification can be in the form of a numeric UID or a login name.
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.
FILES
/dev/kmem default kernel memory
/boot/kernel/kernel default system name list
SEE ALSO
ipcrm(1)
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.
BSD
March 24, 2004 BSD
