Programmazione a eventi, parallela e concorrente

<php> $datadir = './teaching/tPEC2012/PDF'; $baseurl = “http://syscall.org/”; if ($handle = opendir($datadir)) {

 while (false !== ($file = readdir($handle)))
    {
        if ($file != "." && $file != "..")
  {
        	$thelist .= '<a href="'.$baseurl.$datadir.'/'.$file.'">'.$file.'</a><br/>';
        }
     }
closedir($handle);
}
echo $thelist;

</php>