file_name example

public function RSSCache( $base = '', $age = '' ) {
        self::__construct( $base, $age );
    }

/*=======================================================================*\ Function: set Purpose: add an item to the cache, keyed on url Input: url from which the rss file was fetched Output: true on success \*=======================================================================*/
    function set ($url, $rss) {
        $cache_option = 'rss_' . $this->file_name( $url );

        set_transient($cache_option, $rss, $this->MAX_AGE);

        return $cache_option;
    }

/*=======================================================================*\ Function: get Purpose: fetch an item from the cache Input: url from which the rss file was fetched Output: cached object on HIT, false on MISS \*=======================================================================*/