Yes, I know that this question is a bit confusing, I just mean "the variables which are acessible from session's command line". 

I am writing an application which runs automatically by upstart on filesystem, to listen to DBus login1 events and thus It runs from root. But after any user logs in I need to listen to his session bus for additional signals. That's why I want to get `DBUS_SESSION_BUS_ADDRESS` of current user.

Other methods of getting `DBUS_SESSION_BUS_ADDRESS` don't work for me, for example `~/.dbus/session-bus/*` files are somehow outdated(?) ie their content does not match one in the environment.