php服务器限速代码

// local file that should be send to the client 

  $local_file = 'test-file.zip'; 

 
  // filename that the user gets as default 

  $download_file = 'your-download-name.zip'; 

  // set the download rate limit (=> 20,5 kb/s) 

  $download_rate = 20.5; 

  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(); 

  // open file stream 

  $file = fopen($local_file, "r"); 

   while (!feof($file)) { 

   // send the current file part to the browser 

  print fread($file, round($download_rate * 1024)); 

  // flush the content to the browser 

  flush(); 

 
  // sleep one second 

   sleep(1); 

  } 


  // close file stream 

   fclose($file); 

 
  } 

 
  else { 

  die('Error: The file '.$local_file.' does not exist!'); 

  }