while ( false !== ( $file = readdir($handle) ) ) {

        if ($file == '.' || $file == '..') { continue; } 
        if (substr($file,0,$cam_len) != $cam_code) { continue; } 

        $date = strtotime(substr($file,$cam_len,strlen($file)-(4+$cam_len)));
        
        $files[$date] = $file; 

} // end while read dir

/* Sort it based on the keys */
rsort($files);