Users and Groups

Users

Check users by looking at /etc/passwd

Add users

Basic usage:
# useradd -m (user)

Important options:

login name -> by default
group -> -G //separate multiple by commas: group1,group2
with home dir -> -m
shell -> -s
full name -> -c

Example more complicated usage:
# useradd -m -c "Bruno Huber" -s /bin/bash -G sudo,systemd-journal bruhub

Remove user

The command userdel can be used to remove users from a system.
Using it with the -r additionally deletes the user home directory and mail spool.
# userdel -r (user)

Add user to groups

Add user to more groups:
# usermod -a -G (group1),(group2) (user)

Alternative command:
# gpasswd -a (user) (group)

Remove user from group

# gpasswd -d (user) (group)

Groups

Check a user's groups with id (user)

Create group

# groupadd (group)

Rename group

# groupmod -n (new_group) (old_group)

Delete group

# groupdel (group)