Ubuntu Users

List all users:

cut -d: -f1 /etc/passwd

Add a new user:

sudo adduser new_username

To remove/delete a user:

sudo userdel username

To delete the home directory for the deleted user account:

sudo rm -r /home/username

To modify the username of a user:

usermod -l new_username old_username

To change the password for a user:

sudo passwd username

To change the shell for a user:

sudo chsh username

To change the details for a user (for example real name):

sudo chfn username