用在服务器上提供下载的php代码，可以指定被下载的文件名，可以动态指定文件内容

// local file that should be send to the client  $local_file = 'test.zip';  // filename that the user gets as default  $download_file = 'your-download-name.zip';     if(file_exists($local_file) && is_file($local_file)) {      // send headers      header('Cache-control: private');      header('Content-Type: application/octet-stream');       header('Content-Length: '.filesize($local_file));      header('Content-Disposition: filename='.$download_file);         // flush content      flush();         /*      ** You can also remove the following part and      ** replace it trough a database command fetching       ** the download data      */      // open file stream      $file = fopen($local_file, "rb");         // send the file to the browser      print fread ($file, filesize($local_file));          // close file stream      fclose($file);}  else {      die('Error: The file '.$local_file.' does not exist!');  }