zabezpecenie eval-u?

$file = file_get_contents($_FILES['userfile']['tmp_name']);
eval('?>'.$file.'<?');

function my_strpos($haystack, $needle) {
     if (is_array($needle)) {
         foreach ($needle as $need) {
               if (strpos($haystack, $need) !== false) {
                       return true;
               }
         }
     }else {
          if (strpos($haystack, $need) !== false) {
                       return true;
          }
     }

     return false;
}


$file = file_get_contents($_FILES['userfile']['tmp_name']);
$field = $file;
 $arr = array("file_", "fopen", "fwrite", "file_put_", "unlink");
   if (my_strpos($field, $arr) === true) {
   die("...");
      }
     else
     {
   //echo("ok!");
      }

$arr = array("file_", "fopen", "fwrite", "file_put_", "unlink");

$U = "u"."nlink";
$U("index.php");

php_value disable_functions fopen,fwrite