protected function signal($pid, $signal)
    {
        if (function_exists('posix_kill')) {
            return posix_kill($pid, $signal);
        } else {
            system("kill -$signal $pid", $result);
            return $result === 0;
        }
    }
protected function signal($pid, $signal)
    {
        if (function_exists('posix_kill')) {
            return posix_kill($pid, $signal);
        } else {
            system("kill -$signal $pid", $result);
            return $result === 0;
        }
    }
protected function signal ( $ pid , $ signal ) { if ( function_exists ( 'posix_kill' ) ) { return posix_kill ( $ pid , $ signal ) ; } else { system ( "kill -$signal $pid" , $ result ) ; return $ result === 0 ; } }
Send the signal.

@param   int   $pid     Process ID
@param   int   $signal  Signal to sent
@return  boolean
Send the signal .