Use session and cookie variables in Smarty Php template

Cookies: if they are in devtools/Application tab, we can access like this:
Chrome Devtools: Name: companyId Value: 8
Smarty: {$smarty.cookies.companyId}

Session variables:
Set: $_SESSION["userid"] = 1
{$smarty.session.userid}

Parameters in url: example: myurl.com?myindex=34
{$smarty.get.myindex}

Get contents of an array, $_SESSION for example:
{$smarty.session|@json_encode}

To see which file is running the current page:
{$smarty.server.SCRIPT_NAME}