A simple router for PHP built-in server.

router.php

<?php
route('GET', '/', function ($data) {
    echo 'Welcome!';
});

return false;

function route($method, $uri, $callback) {
    $REQUEST_URI = explode('?', $_SERVER["REQUEST_URI"])[0];
    
    if ($uri == $REQUEST_URI && $method == $_SERVER['REQUEST_METHOD']) {
        call_user_func($callback, $_REQUEST);
        exit;
    }
}

php -S localhost:8080 router.php