spelling out how to use php's proc

proc_usage.php

<?php
$process = proc_open(
            'wc', // cmd to run
            // define yr pipes
            [
              ['file', __FILE__, 'r'],      // stdin (passing file to wc)
              ['file', 'output.txt' , 'w']  // stdout (output, we could also echo stream_get_contents of $pipes[1])
            ],
            // var to store the above
            $pipes
            );
if ( is_resource($process) ) {
  // since we don't need to push anything in to stdin, we'll close the process
  $return = proc_close($process);
}