preg_match

        $url = "https://www.baidu.com/api/users";

        if (preg_match('/api/', $url)) {
            return "包含";
        } else {
            return "不包含";
        }

strpos

        $url = "https://www.baidu.com/";
        if (strpos($url, 'baidu') !== false) {
            return "包含";
        } else {
            return "不包含";
        }