			        Process Control

Connected Subprocesses

	     pid = propen (process, in, out)
	   stat = prclose (pid)
	 stat = prgetline (in, lbuf)
		  prredir (pid, stream, new_fd)
		 prsignal (pid, signal)
		 prupdate (message)

	    pid = propcpr (process, in, out)
	   stat = prclcpr (pid)



Detached Processes

	    job = propdpr (process, bkgfile)
	   stat = prcldpr (job)
	     y/n = prdone (job)
		   prkill (job)
