adduser <username>
passwd <username>
passwd
usermod -l <newUsername> <oldUsername>
usermod -d /home/<newHomeDir> -m <username>
usermod -L <username>
usermod -U <username>
deluser <username>
deluser --remove-home <username>
usermod -aG <groupname> <username>
groups <username>
addgroup <groupname>
delgroup <groupname>
sudo -i
su - <username>
cut -d: -f1 /etc/passwd
cut -d: -f1 /etc/group
passwd -l <username>
passwd -u <username>