Cache

<?php
 
// The location of the cache file
$cache_file = '/tmp/tweetmeme';
 
$url = 'http://api.tweetmeme.com/url_info';
 
// If the file doesn't exist or 1 hour has passed since the last update, write the new data to the file
if(!file_exists($cache_file) OR (time() - filemtime($cache_file) > 3600)) {
 
	$data = file_get_contents($url);
	$data = trim($data);
 
	$xml_string = simplexml_load_string($data);
 
	// If there is data and the data is XML, write it
	if($data != '' AND $xml_string !== FALSE) {
 
		file_put_contents($cache_file, $data);
 
	}
 
} else {
 
	$data = file_get_contents($cache_file);
 
}
 
echo $data;