Linux/User Management

Terminal commands to manage user accounts in linux.

Creating a New User

The most basic implementation is:

• useradd <user_name>

From there, you can add argument options such as:

• -M or --no-create-home - Skips creating a home directory for user.
• -N or --no-user-group - Skips creating a group with the same name as user.
• -G or --groups - Set additional user groups user is part of, during user creation.
• -r or --system - Create a "system" account. Aka, a user with no password, no home directory, and is unable to log in.

Example:
useradd -G admins,webadmin,developers my_user
This creates a user called "my_user" that is associated with groups "admins", "webadmin", and "developers".

Updating User Password

Update password for current account:

• passwd

Update password for another user account:

• passwd <user_name>

Group Management

Groups and Group Membership

View check all existing groups:

• cat /etc/group

View all members of a group:

• getent group <group_name>

View all groups for given user:

• groups <user_name>

Adding and Removing User Groups

Add current user to group:

• groupadd <group_name>

Add given user to group:

• usermod -a -G <group_name> <user_name>

Remove user from group:

• gpasswd -d <user_name> <group_name>