Linux User Management Cheat Sheet

Manage user accounts, groups, and permissions.

What this cheat sheet is for

This linux user management reference helps you complete common developer tasks quickly and avoid repeated trial-and-error when working under deadlines.

When you need a reliable command or pattern during debugging and incident response.
When you are implementing a feature and want a known-good syntax example immediately.
When onboarding teammates and documenting repeatable workflows for daily use.
When reviewing pull requests and verifying that command usage follows best practices.

Add User

Create new user account.

sudo useradd username
sudo useradd -m username
sudo useradd -s /bin/bash username
sudo useradd -m -s /bin/bash -G sudo username

Delete User

Remove user account.

sudo userdel username
sudo userdel -r username

Modify User

Change user properties.

sudo usermod -aG groupname username
sudo usermod -s /bin/zsh username
sudo usermod -L username
sudo usermod -U username

Change Password

Set or change password.

passwd
sudo passwd username
passwd -l username
passwd -u username

Switch User

Switch to another user.

su username
su -
su - username

Sudo

Execute as root.

sudo command
sudo -i
sudo -u username command
sudo visudo

Group Management

Manage groups.

sudo groupadd groupname
sudo groupdel groupname
sudo gpasswd -a username groupname
sudo gpasswd -d username groupname

View Users

List users and info.

cat /etc/passwd
whoami
who
w
id username

Common mistakes / Pitfalls

People often copy a command or pattern without adapting placeholders, which can break production workflows unexpectedly.
It is easy to forget environment-specific differences, so always verify behavior in your shell, runtime, or API gateway before shipping.
Many errors come from skipping small validation steps, so test with realistic sample input before relying on the result.

Last updated: February 2026