How to properly write condition in Smarty template?

Question

PHP

It is necessary to display / not display content depending on the url address.
Example:
{if $smarty.server.REQUEST_URI == "/page"}
Everything would be fine, but this condition needs to work for:
/page-123
/page-newpage
/page-bla-bla-bla
How to implement?
UPD:
{if strpos($smarty.server.REQUEST_URI, "text_that_should_be_in_url")}

Answer 1

these checks should go to php, smart is a template engine, it is for html output. This is simply not true. But on the off-forum, smarty says that almost all PHP functions work. For example, checking for a number would look like this:
{if is_numeric($getnumeric)}