Used for https://github.com/star-inc/PBP_Demo-LINEBOT

normalize-url.php

<?php
/**
 * Given a URL, normalize that URL.
 * @param String URL
 * @return String Normalized URL
 */
function normalizeUrl($input_url)
{
    $newUrl = "";
    $url = parse_url($input_url);
    $defaultSchemes = array("http" => 80, "https" => 443);

    if (isset($url['scheme'])) {
        $url['scheme'] = strtolower($url['scheme']);
        $newUrl .= "{$url['scheme']}://";
    } else {
        return normalizeUrl("http://" . $input_url);
    }

    if (isset($url['host'])) {
        $url['host'] = strtolower($url['host']);
        // Seems like a valid domain, properly validation should be made in higher layers.
        if (preg_match("/[a-z]+\Z/", $url['host'])) {
            if (preg_match("/^www\./", $url['host']) && gethostbyname($url['host']) == gethostbyname(str_replace("www.", "", $url['host']))) {
                $newUrl .= str_replace("www.", "", $url['host']);
            } else {
                $newUrl .= $url['host'];
            }

        } else {
            $newUrl .= $url['host'];
        }

    }

    if (isset($url['port'])) {
        // Strip scheme default ports
        if ($defaultSchemes[$url['scheme']] !== $url['port']) {
            $newUrl .= ":{$url['port']}";
        }
    }

    if (isset($url['path'])) {
        // Case normalization
        $url['path'] = strtolower($url['path']);

        //Strip duplicate slashes
        while (preg_match("/\/\//", $url['path'])) {
            $url['path'] = preg_replace("/\/\//", "/", $url['path']);
        }

        /*
         * Decode unreserved characters, http://www.apps.ietf.org/rfc/rfc3986.html#sec-2.3
         * Heavily rewritten version of urlDecodeUnreservedChars() in Glen Scott's url-normalizer.
         */

        $u = array();
        for ($o = 65; $o <= 90; $o++) {
            $u[] = dechex($o);
        }

        for ($o = 97; $o <= 122; $o++) {
            $u[] = dechex($o);
        }

        for ($o = 48; $o <= 57; $o++) {
            $u[] = dechex($o);
        }

        $chrs = array('-', '.', '_', '~');
        foreach ($chrs as $chr) {
            $u[] = dechex(ord($chr));
        }

        $url['path'] = preg_replace_callback(array_map(create_function('$str', 'return "/%" . strtoupper($str) . "/x";'), $u), create_function('$matches', 'return chr(hexdec($matches[0]));'), $url['path']);
        // Remove directory index
        $defaultIndexes = array("/default\.aspx/" => "default.aspx", "/default\.asp/" => "default.asp", "/index\.html/" => "index.html", "/index\.htm/" => "index.htm", "/default\.html/" => "default.html", "/default\.htm/" => "default.htm", "/index\.php/" => "index.php", "/index\.jsp/" => "index.jsp");
        foreach ($defaultIndexes as $index => $strip) {
            if (preg_match($index, $url['path'])) {
                $url['path'] = str_replace($strip, "", $url['path']);
            }

        }

        /**
         * Path segment normalization, http://www.apps.ietf.org/rfc/rfc3986.html#sec-5.2.4
         * Heavily rewritten version of removeDotSegments() in Glen Scott's url-normalizer.
         */

        $new_path = '';
        while (!empty($url['path'])) {
            if (preg_match('!^(\.\./|\./)!x', $url['path'])) {
                $url['path'] = preg_replace('!^(\.\./|\./)!x', '', $url['path']);
            } elseif (preg_match('!^(/\./)!x', $url['path'], $matches) || preg_match('!^(/\.)$!x', $url['path'], $matches)) {
                $url['path'] = preg_replace("!^" . $matches[1] . "!", '/', $url['path']);
            } elseif (preg_match('!^(/\.\./|/\.\.)!x', $url['path'], $matches)) {
                $url['path'] = preg_replace('!^' . preg_quote($matches[1], '!') . '!x', '/', $url['path']);
                $new_path = preg_replace('!/([^/]+)$!x', '', $new_path);
            } elseif (preg_match('!^(\.|\.\.)$!x', $url['path'])) {
                $url['path'] = preg_replace('!^(\.|\.\.)$!x', $url['path']);
            } else {
                if (preg_match('!(/*[^/]*)!x', $url['path'], $matches)) {
                    $first_path_segment = $matches[1];
                    $url['path'] = preg_replace('/^' . preg_quote($first_path_segment, '/') . '/', '', $url['path'], 1);
                    $new_path .= $first_path_segment;
                }
            }
        }
        $newUrl .= $new_path;
    }

    if (isset($url['fragment'])) {
        unset($url['fragment']);
    }

    // Sort GET params alphabetically, not because the RFC requires it but because it's cool!
    if (isset($url['query'])) {
        if (preg_match("/&/", $url['query'])) {
            $s = explode("&", $url['query']);
            $url['query'] = "";
            sort($s);
            foreach ($s as $z) {
                $url['query'] .= "{$z}&";
            }

            $url['query'] = preg_replace("/&\Z/", "", $url['query']);
        }
        $newUrl .= "?{$url['query']}";
    }

    return $newUrl;
}