getBaseUrl.php

function getBaseUrl($includeTrailingSlash = FALSE)
{
    $protocol = (isset($_SERVER['HTTPS']) && 'off' !== $_SERVER['HTTPS']) ? 'https' : 'http';
    $domain = php_uname('n');
    $port = '';

    if (isset($_SERVER['HTTP_HOST'])) {
        $domain = filter_input(
            INPUT_SERVER,
            'HTTP_HOST',
            FILTER_SANITIZE_STRING,
            FILTER_FLAG_NO_ENCODE_QUOTES
        );
    } elseif (isset($_SERVER['SERVER_NAME'])) {
        $domain = filter_input(
            INPUT_SERVER,
            'SERVER_NAME',
            FILTER_SANITIZE_STRING,
            FILTER_FLAG_NO_ENCODE_QUOTES
        );
    }

    if (FALSE === strpos($domain, ':')
        && (('http' === $protocol && 80 !== (int) $_SERVER['SERVER_PORT'])
            || ('https' === $protocol && 443 !== (int) $_SERVER['SERVER_PORT']))
    ) {
        $port = ':' . (int) $_SERVER['SERVER_PORT'];
    }

    $pathInfo = pathinfo($_SERVER['PHP_SELF']);
    $baseUrl = rtrim($pathInfo['dirname'], '/');
    if($baseUrl) {
        $basePath = basename(__DIR__);
        $posPath = strpos($baseUrl, $basePath);
        if($posPath){
          $baseUrl = substr($baseUrl, 0, strlen($basePath) + 1);
        } else {
            $baseUrl = '';
        }
    }
    $trailingSlash = $includeTrailingSlash ? '/' : '';

    return "${protocol}://${domain}${port}${baseUrl}${trailingSlash}";
}