$parm = "dwn";
$path = WB_PATH.MEDIA_DIRECTORY."/files/";
$ip = preg_replace(['/.d*$/','/[da-f]*:[da-f]*$/'],['.XXX','XXXX:XXXX'],$_SERVER['REMOTE_ADDR']);
if(isset($_GET[$parm])) {
  $id = $_GET[$parm];
  if(isset($_SESSION['dyndwn'][$id])) {
    $download =  $_SESSION['dyndwn'][$id];
    $contenttype = mime_content_type ($download);
    $filename = str_replace($path,'',$download);
    error_log("$ip - Download: $filename");
    ob_end_clean();
    header("Content-Description: File Transfer");
    header("Content-type: $contenttype");
    header('Content-Disposition: attachment; filename="'.$filename.'"');
    header("Content-Length: " . filesize($download));
    header('Pragma: public');
    header("Expires: 0");
    readfile($download );
    die();
  }
} else {
  if(!isset($file)) return true;   // no filename
  if(!isset($title)) $title = $file;   // no link text
  if(!file_exists($path.$file)) return true;  // file does not exist
  $guid = bin2hex(random_bytes(8));
  $_SESSION['dyndwn'][$guid] = $path.$file;
  return '<a target="dwn'.$guid.'" href="?'.$parm.'='.$guid.'">'.$title.'</a><iframe style="height:0;width:0;display:none;" name="dwn'.$guid.'"></iframe>';
}
return true;