Using the class:
1. upload the file "cache.class.php" somewhere at your server.
2. create new directory at the server and make it writable.
3. in the file where you'll use the class, include the class
4. make an instance of the class
$cache = new cache();
5. setup the cache dir:
$cache->cache_dir = './others/cache'; // the default is ./cache
6. follow the steps from the example (example.php).