oh no! Destroyed my admin account using USERMOD :(

[Alan McKinnon]

On Mon, 2006-07-10 at 11:24 +0800, Gabriel M Dragffy wrote:
> Hi,
> I wanted to add my default superuser to the nogroup group. I couldn't
> find a gui tool in gnome so I read the man page of usermod. I ran the
> command    $sudo usermod -Gnogroup gabe
> I thought this would have added me to the group but it seems to have
> removed all the other groups and now I can't do anything with my
> computer. I still have a terminal open so I can run sudo for the next
> fifteen minutes, and I'm going to set a root password. Could someone
> please tell me the default groups that the superuser is in?
> Then I will add my user back in. Please respond quickly!!

So you got caught out as well :-)

usermod -G is intended to be used when the user is first created, where
you list all the supplementary groups the user will be a member of. It
removes all groups, then adds the list you provide. For future
reference, the command you wanted was:

gpasswd -a <username> <group>

which adds the user to the group and leaves all others unaffected.

You want to add user gabe to the admin group to be able to sudo.

alan