Debian user administration

Use adduser and addgroup for user administration.

add a new user

$ adduser [--shell shell] [--ingroup group] username

Configuration file is /etc/adduser.conf. Creates home directory with files from /etc/skel. By default it creates for the user a group with the same name.

add a system user

$ adduser --system

A system user can't login.

add group to user

$ adduser user group

change primary group of user

$ usermod -g group user