proc_terminate() allows you terminate the process and continue with other tasks. You may poll the process (to see if it has stopped yet) by using the proc_get_status() function. However this is only possible with PHP 5.2.2 or newer, as previous versions destroyed the given process resource.
The proc_open() resource that will be closed.
This optional parameter is only useful on POSIX
operating systems; you may specify a signal to send to the process
kill(2) system call. The default is