Semaphore Options

Qjob uses semaphores covered in our previous article "Implementing Semaphores in the Shell", available from:

http://www.samag.com/documents/s=9238/sam0408f/0408f.htm

-I -- Initialize the semaphore and set the number of resources.

-P -- Grab a resource and decrement the value of the semaphore. Wait until a resource becomes available if necessary.

-V -- Increment the value of the semaphore if and only if the calling process has a resource to return.

-q -- Use with the -P operation to place processes that are waiting for a resource in a queue.

-t -- Set the number of times the P operation will try to obtain a resource before timing out if none are available. By default, the P operation keeps trying until is a resource is obtained.

-s -- Set the number of seconds the P operation sleeps between tests. By default, processes waiting for a resource sleep for one second before trying again.