/**
 * @author Filip Procházka <[email protected]>
 */
class Process
{
    /**
     * @return string
     * @throws ProcessException
     */
    public static function execute($cmd)
    {
        $output = NULL;
        $spec = array(
            0 => array("pipe", "r"), // stdin is a pipe that the child will read from
            1 => array("pipe", "w"), // stdout is a pipe that the child will write to
            2 => array("pipe", "w"), // errors
        );

        if (is_resource($process = proc_open($cmd, $spec, $pipes))) {
            fclose($pipes[0]);
            stream_set_blocking($pipes[1], 1);
            $output = stream_get_contents($pipes[1]);
            fclose($pipes[1]);
            @fclose($pipes[2]);

            if (0 !== proc_close($process)) {
                throw new ProcessException("Error occured while executing: `$cmd`\n\n" . $output);
            }

        } else {
            throw new ProcessException("Could not execute: `$cmd`");
        }

        return $output;
    }

}



/**
 * @author Filip Procházka <[email protected]>
 */
class ProcessException extends \RuntimeException
{

}


$output = Process::execute('plistgenerator.py --url ' . escapeshellarg($url) . ' --path ' . escapeshellarg($_GET['plist']));