php控制文件下载速度的方法

本文实例讲述了php控制文件下载速度的方法。分享给大家供大家参考。具体实现方法如下：

本文实例讲述了php控制文件下载速度的方法。分享给大家供大家参考。具体实现方法如下：

<?php
 /*
 * set here a limit of downloading rate (e.g. 10.20 Kb/s)
 */
 $download_rate = 10.20;
 $download_file = 'download-file.zip'; 
 $target_file = 'target-file.zip';
 if(file_exists($download_file)){
 /* headers */
 header('Last-Modified:'.gmdate('D, d M Y H:i:s').'GMT');
 header('Cache-control: private');
 header('Content-Type: application/octet-stream');
 header('Content-Length: '.filesize($download_file));
 header('Content-Disposition: filename='.$target_file);
 /* flush content */
 flush();
 /* open file */
 $fh = @fopen($download_file, 'r');
 while(!feof($fh)){
 /* send only current part of the file to browser */
 print fread($fh, round($download_rate * 1024));
 /* flush the content to the browser */
 flush();
 /* sleep for 1 sec */
 sleep(1);
 }
 /* close file */
 @fclose($fh);
 }else{
 die('Fatal error: the '.$download_file.' file does not exist!');
 }
?>

希望本文所述对大家的php程序设计有所帮助。