Q:

How do I add a user to a group

How do I add a user to a group.
This is on a system with no root password and only a single user pi with sudo privileges.
usermod seems to have been designed to make this as difficult as possible.

A:

You can use usermod or edit the group file directly
# usermod -a -G ${group} ${user}

# vi /etc/group
...
wheel:x:10:root,user1,user2
...

Just remember group changes do not always propagate to active sessions. If you are changing your own user logout and then log back in.

