php实现下载限制速度示例分享

// 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!);
}