Chapter 5: User Administration

User Commands

useradd -m -s /bin/bash username
passwd username
usermod -aG sudo username
userdel -r username

Group Commands

groupadd devs
usermod -aG devs alice
gpasswd -d alice devs
id alice

sudo

sudo command
sudo -l
visudo

Password Policy

chage -M 90 user
passwd -l user

Notes

• UID 0=root, 1000+=users
• Always -aG to append groups
• Use visudo to edit sudoers