Linux user account setup (basic)

Passwords
To change a password for another user:

# passwd [username]

To lock an account and unlock an account:

# passwd -l [username]
# passwd -u [username]

WARNING: If Locking the root account ensure that you have allowed and tested access with sudo first!
Users and Groups Creation and DeletionTo list the groups a user is a member of:

# groups [username]

Groups:

# groupadd [groupname]

To create a user and set primary group:

# useradd -g [groupname] [username]

To create a user and set secondary group:

# useradd -G [groupname] [username]

To add group to existing users secondary groups:

# usermod -a -G [groupname] [username]

To delete a user:

#userdel -r [username]

-r deletes the users home directory as well as account

Misc
To see a summary of logins to date (leave username blank to see all logins):

# last [username]