define('SHOP_KEYWORDS', ["shop", "cart"]);
$site = file_get_contents('url');
$words = implode("|", SHOP_KEYWORDS);
preg_match_all("/($words)/", $site, $matches);
switch (count($matches)) {
case 10 : echo 'not shop'; break;
case 30 : echo "shop, or not"; break;
case 90 : echo "shop"; break;
}