Top Ten Web Game Rankings 2013 PHP Code to Control Web Page Expiration Time

Of course, the prerequisite is to turn on reload_into_ims on, a function in CDN. In this way, users will not be afraid of sending no-cache. Because this will convert no-cache into If-Modified-Since. So we write programs mainly for If-Modified -Since control is fine. Remember, in the cache system architecture, it is best to be controlled by the backend, so the best way is to manage expiration by program. Hehe, I only know PHP, so I will use PHP to write one. The same goes for programs.
See my program below, haha, it expires in 5 minutes.

Copy the code The code is as follows:

$headers = apache_request_headers();
$client_time = (isset($headers[' If-Modified-Since']) ? strtotime($headers['If-Modified-Since']) : 0);
$now=gmmktime();
$now_list=gmmktime()-60*5;
if ( $client_time<$now and $client_time >$now_list){
header('Last-Modified: '.gmdate('D, d M Y H:i:s', $client_time).' GMT', true, 304);
exit(0);
}else{
header('Last-Modified: '.gmdate('D, d M Y H:i:s', $now).' GMT', true, 200);
}
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The above introduces the top ten web game rankings in 2013. The PHP code for controlling the expiration time of web pages, including the top ten web game rankings in 2013. I hope it will be helpful to friends who are interested in PHP tutorials.