Users, Permissions and Groups

Users

Command Action
adduser Create a new user
cat /etc/passwd View all users on the system
cat /etc/passwd | grep {name} search for user
chsh -s /path/to/shell Change default shell for a user
id View user details
passwd Change your own password
passwd Change user password
su - Switch to another user
userdel -r Delete a user and their home directory
usermod -aG sudo Add user to sudo group
usermod -l <new_username> <old_username> Change username
visudo (Add: ALL=(ALL:ALL) ALL) Grant sudo privileges to a user
whoami View current username

Groups

Command Action
grep '^sudo:' /etc/group Display members of the sudo group
groups View groups a user belongs to

Permissions

Command Action
chgrp new_group file Change group
chmod ### file Change permissions
chown -R new_owner:new_group dir Change owner and group
chown new_owner dir Change owner