core-bundle/src/Resources/contao/library/Contao/Environment.php
protected static function path()
	{
		$request = System::getContainer()->get('request_stack')->getCurrentRequest();

		if ($request === null)
		{
			return '';
		}

		return $request->getBasePath();
	}
protected static function path()
	{
		$request = System::getContainer()->get('request_stack')->getCurrentRequest();

		if ($request === null)
		{
			return '';
		}

		return $request->getBasePath();
	}
Return the relative path to the base directory (e.g. /path)

@return string The relative path to the installation