Canonical URLs

gistfile1.aw

<?php

	function get_url($with_query_string = TRUE, $canonical_filter = array())
	{
		$query  = NULL;
		$path   = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
		$port   = ':' . $_SERVER['SERVER_PORT'];
		$host   = $_SERVER['SERVER_NAME'];
		$scheme = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off')
			? 'https'
			: 'http';

		if (($scheme == 'http' && $port == 80) || ($scheme == 'https' && $port == 443)) {
			$port = NULL;
		}

		if ($with_query_string) {

			$canonical_params = $_GET;

			foreach ($canonical_filter as $filter) {

				$match = FALSE;

				if (strpos($filter, '*') !== FALSE) {
					$regex_match = str_replace('*', '(.*?)', $filter);

					foreach ($canonical_params as $param => $value) {
						if (preg_match('/' . $regex_match . '/', $param)) {
							unset($canonical_params[$param]);
						}
					}
				} else {
					foreach ($canonical_params as $param => $value) {
						if ($filter == $param) {
							unset($canonical_params[$param]);
						}
					}
				}
			}

			$query = '?' . http_build_query($canonical_params);
		}

		$url = $scheme . '://' . $host . $port . $path . $query;
	}