Super simple page caching.
 

When your project isn’t based on a CMS or framework, it can be a good idea to implement a simple caching system on your pages. The following code snippet is very simple, but works well for small websites.

PHP Code:
// define the path and name of cached file
$cachefile = 'cached-files/'.date('M-d-Y').'.php';
// define how long we want to keep the file in seconds. I set mine to 5 hours.
$cachetime = 18000;
// Check if the cached file is still fresh. If it is, serve it up and exit.
if (file_exists($cachefile) && time() - $cachetime < filemtime($cachefile)) {
include($cachefile);
exit;
}
// if there is either no file OR the file to too old, render the page and capture the HTML.
ob_start();
?>

output all your html here.

// We're done! Save the cached content to a file
$fp = fopen($cachefile, 'w');
fwrite($fp, ob_get_contents());
fclose($fp);
// finally send browser output
ob_end_flush();
?>

thanx for sharing.