UniBasic Commands Reference - Rocket Software

Parameters
The following table describes each parameter of the syntax.
Parameter Description
Examples
In the following example, the program statement reserves resource 12 if another
program is not using it. If resource 12 is already in use, the current program suspends
execution and waits until UniData unlocks resource 12.
LOCK 12
In the next example, the program segment locks resource 44 if it is available. If it has
already been locked, the program attempts to lock resource 45. If both resources are
unavailable, the program stops.
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resource.num Specifies a number associated with a resource. resource.num can
be any number from 0 through 63.
For assistance in assigning resource numbers, see your system
administrator.
THEN statements END Specifies statements to execute if the LOCK statement executes
successfully.
ELSE statements END Specifies statements to execute if another user has reserved the
resource (using the same resource number) so that the LOCK
statement fails to lock it.
If you do not specify an ELSE clause and the requested resource
has already been locked, the current program waits until that
resource is released.
Use the ECL command DEFAULT.LOCKED.ACTION BELL
to make the terminal beep while you wait for UniData to release
the lock.
LOCK Parameters
T1 = 44; T2 = 45
LOCK T1 ELSE LOCK T2 ELSE STOP