Table of Contents:

• users and groups
  • add users
    • ubuntu
    • centos
  • modify users
  • delete users

users and groups

add users

• create user with home folder and login sudo useradd -m username -p PASSWORD
• add user to sudo group on ubuntu

  ubuntu

  usermod -aG sudo arvin

  centos

  usermod -aG wheel arvin

  modify users

• set expiry time for user

  sudo usermod --expiredate 1 arvin
  

• lock user password ( disable ssh )

  sudo passwd -l arvin
  

• enable user password

  sudo passwd -u training
  

• set expiry time for user password

  sudo passwd -e  2013-05-31 arvin
  

• enable root user

  su -
  passwd
  

  delete users

• r option removes home directory

  userdel -r arvin