class Timer {
var $timers =array();
function Timer()
{
}
function timerStart($name = 'default')
         {
         $time_portions = explode(' ',microtime());
         $actual_time = $time_portions[ 1 ].substr($time_portions[ 0 ], 1 );
         $this -> timers['$name'] = $actual_time;
         }
function timerStop($name = 'default')
         {
         $time_portions = explode(' ',microtime());
         $actual_time = $time_portions[ 1 ].substr($time_portions[ 0 ], 1 );
         $elapsed_time = bcsub($actual_time, $this -> timers['$name'], 6 );
         return $elapsed_time;
         }
}

$tim = new Timer();

$tim -> timerStart('total');

$tim -> timerStart();
if ($localdir = opendir(".")) {
    while (false !== ($files = readdir($localdir))) {
        if ($files != "." && $files != ".." && !is_dir($files)) {
array_push($f, strtolower($files));
        }
    }
    closedir($localdir);
}
print ("time1: ".$tim -> timerStop());

$tim -> timerStart();
$result_tr = array_diff ($f, $contents);
print ("time2: ".$tim -> timerStop());
print ("Total: ".$tim -> timerStop('total')."<br>");

time1:  0 . 453968 
time2:  0 . 009770 
Total:  0 . 009830