php怎么控制文件下载速度，php编写的程序中实现文件下载，有时需要限速下载，其实用php header函数就可以控制文件下载速度，这里分享二个php实例代码，供大家参考。一、php控制文件下载速度的方法。
代码：
复制代码 代码示例:二、php下载限制速度代码
php限制下载速度实现代码：
复制代码 代码示例:// 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!');}