Symfony\Component\HttpFoundation\Request::getRelativeUriForPath PHP Method

    public function getRelativeUriForPath($path)
    {
        // be sure that we are dealing with an absolute path
        if (!isset($path[0]) || '/' !== $path[0]) {
            return $path;
        }

        if ($path === $basePath = $this->getPathInfo()) {
            return '';
        }

        $sourceDirs = explode('/', isset($basePath[0]) && '/' === $basePath[0] ? substr($basePath, 1) : $basePath);
        $targetDirs = explode('/', isset($path[0]) && '/' === $path[0] ? substr($path, 1) : $path);
        array_pop($sourceDirs);
        $targetFile = array_pop($targetDirs);

        foreach ($sourceDirs as $i => $dir) {
            if (isset($targetDirs[$i]) && $dir === $targetDirs[$i]) {
                unset($sourceDirs[$i], $targetDirs[$i]);
            } else {
                break;
            }
        }

        $targetDirs[] = $targetFile;
        $path = str_repeat('../', count($sourceDirs)).implode('/', $targetDirs);

        // A reference to the same base directory or an empty subdirectory must be prefixed with "./".
        // This also applies to a segment with a colon character (e.g., "file:colon") that cannot be used
        // as the first segment of a relative-path reference, as it would be mistaken for a scheme name
        // (see http://tools.ietf.org/html/rfc3986#section-4.2).
        return !isset($path[0]) || '/' === $path[0]
            || false !== ($colonPos = strpos($path, ':')) && ($colonPos < ($slashPos = strpos($path, '/')) || false === $slashPos)
            ? "./$path" : $path;
    }