php - How to block some Pages if in .txt file

How to block (redirect) a Page if the Page is in a .txt file:

I have this snippet - the good news is the url in block.txt will be blocked (white Site) but i want it to redirect to /file-not-found.php

<?php
list($blockExist, $blockData) = array(false, null);

if (is_string($blockData = @file_get_contents('/block.txt'))) {
    $blockData = preg_replace('/\s+/', '', $blockData);
}

if (isset($_SERVER['REQUEST_URI'])) {
    $httpLink = explode('?', $_SERVER['REQUEST_URI']);
    $httpLink = $httpLink[0] == '/' ? null : $httpLink[0];
}

if ($blockData != null && $httpLink != null && stripos("{$blockData}http://", "{$httpLink}http://") !== false) {
    $blockExist = true;
}

if ($blockExist) {
    require_once dirname(__FILE__) . '/file-not-found.php';
    exit;
}
?>
Copy code