The ipcs utility shall conform to the Base Definitions volume of
POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines.
The ipcs utility accepts the following options:
-q Write information about active message queues.
-m Write information about active shared memory segments.
-s Write information about active semaphore sets.
If -q, -m, or -s are specified, only information about those
facilities shall be written. If none of these three are
specified, information about all three shall be written subject
to the following options:
-a Use all print options. (This is a shorthand notation
for -b, -c, -o, -p, and -t.)
-b Write information on maximum allowable size. (Maximum
number of bytes in messages on queue for message
queues, size of segments for shared memory, and number
of semaphores in each set for semaphores.)
-c Write creator's user name and group name; see below.
-o Write information on outstanding usage. (Number of
messages on queue and total number of bytes in messages
on queue for message queues, and number of processes
attached to shared memory segments.)
-p Write process number information. (Process ID of the
last process to send a message and process ID of the
last process to receive a message on message queues,
process ID of the creating process, and process ID of
the last process to attach or detach on shared memory
segments.)
-t Write time information. (Time of the last control
operation that changed the access permissions for all
facilities, time of the last msgsnd() and msgrcv()
operations on message queues, time of the last shmat()
and shmdt() operations on shared memory, and time of
the last semop() operation on semaphores.)
