.forward being run by a program the switches users to the one it applies to. It only runs with the primary rights of this user.

If you need to get ALL the groups, you need to change the "su" to and "su -". Personally, I've never done it, so I don't know how to do it.

I am betting someone has, but searching for this particular thing would strain even the best of any Google-Fu *ANYONE* has to offer.

forward is a messy messy messy search term. "forward looking" "going forward"... and so on.