How to get PID from PHP function exec() in Windows?

[lody90]

I have always used:\[code\]$pid = exec("/usr/local/bin/php file.php $args > /dev/null & echo \$!");\[/code\]But I am using an XP virtual machine to develop a web app and I have no idea how to get the pid in windows.I tried this on a cmd:\[code\]C:\\wamp\\bin\\php\\php5.2.9-2\\php.exe "file.php args" > NUL & echo $!\[/code\]And it gets the file executed, but the output is "$!"How can I get the pid into the var $pid? (using php)