%semctl() function

The %semctl() function performs semaphore control operations.

For Windows: Not Supported

Syntax

code = %semctl(sem-ID, semnum, cmd, arg)

`sem-ID`	Semaphore ID returned by a call to %semget().
`semnum`	Semaphore number in the set, when applicable (depending on `cmd`).
`cmd`	Valid values for `cmd` are defined in sem.h and ipc.h. The commands below are executed with respect to the semaphore specified by `sem-ID` and `semnum`:
	getval	Returns the value of semval.
	setval	Sets semval to the value of `arg`.
	getpid	Returns the value of sempid.
	getncnt	Returns the value of semncnt.
	getzcnt	Returns the value of semzcnt.
	The commands below apply to all semaphores in the set:
	getall	Place all the semaphore values in the `arg` dimensioned array.
	setall	Set all the semaphores to the values contained in the dimensioned array `arg`.
	These commands are also available:
	ipc$stat	Return a dimensioned array that contains the various fields of the UNIX semaphore structures. The elements are (see the UNIX system documentation):
		1 sem_perm.uid
		2 sem_perm.cid
		3 sem_perm.guid
		4 sem_perm.gcid
		5 sem_perm.mode
		6 sem_perm.seq
		7 sem_perm.key
		8 sem_nsems
		9 sem_otime
		10 sem_ctime
	ipc$set	Sets the values of the below members of the data structure associated to `sem-ID` to the first three elements of the array `arg`:
		1 sem_perm.uid
		2 sem_perm.gid
		3 sem_perm.mode
	ipc$rmid	Removes the semaphore identifier.
`arg`	Dimensioned array that contains the argument.

include dm,bp,unix.h ipc.h
include dm,bp,unix.h sem.h
* Set initial semaphore values
dim val(3)
mat val=0
%semctl(sem-ID, 0, setall, val)