zx-spectrum

i also try this
i write searh2.php file what run then user click on url

<
$category == $_GET['c'];
		<h2 class="pagetitle">Search results</h2>
		<?php
		$category = wp_specialchars($c, 1);
		do_action(do_search_by_category, $category ); ?>

and put it into themes\default dir that is current active
and put code like
<a href="search2.php?c=1">Cat 1</a>" into sidebar

bun then i click on this url wordpress write “file not found”

i tried copy this file into www folder
but when search2.php run its dont see any plugin or wordpress functions