'trying' to make a script to execute by script... definitely note safe, but it doesn't matter - it doesn't work :-P

php_server_on_demand.php

<?php

function exec_local_url($url) {
    exec('/usr/bin/wget -O - -q -t 1 "http://'. $_SERVER['HTTP_HOST'] .'/'
      . addslashes($url) . '" >/dev/null 2>&1'
    );
}

exec_local_url('php -S localhost:1000 -t .');
// exec(php -S localhost:1000);