/**
* Static function to simply autenticate users.
* Can be used for other purposes.
* @param string $login the linux username
* @param string $password password
* @access public
* @return bool - true if login and password is right
*/
public static function autenticate($login, $password)
{
self::$username = $login;
$process = new Process("su " . escapeshellarg($login));
usleep(500000);
$process->put($password);
$process->put(chr(13));
usleep(500000);
return (bool) (!$process->close());
}