PHP 修改 https 和 http （http和https之间转换）

function set_http_type($url, $type = 0)
    {
        $domainTop = substr($url, 0, 5);
        if ($type) {
            if ($domainTop == 'https') $url = 'http' . substr($url, 5, strlen($url));
        } else {
            if ($domainTop != 'https') $url = 'https:' . substr($url, 5, strlen($url));
        }
        return $url;
    }