php下载远程大文件(获取远程文件大小)的实例

<"'.$file.'"');
  header('Content-Transfer-Encoding: binary');
  header('Expires: 0');
  header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
  header('Pragma: public');
  header('Content-Length: ' . $size);

  ob_clean();
  ob_end_flush();
  set_time_limit(0);
  
  $chunkSize = 1024 * 1024;
  while (!feof($fp)) {
    $buffer = fread($fp, $chunkSize);
    echo $buffer;
    ob_flush();
    flush();
  }
  fclose($fp);
  exit;