Linux User and Group Management
Linux User and Group Management
Introduction
This article provides a comprehensive guide to managing users and groups in Linux. We will cover essential commands and best practices for administering user accounts and permissions.
Creating Users and Groups
useradd
The useradd command is used to create new users. Here's an example:
useradd john
This creates a user named 'john'. You can add options like -m to create a home directory, -g to specify the group, and more. See man useradd for details.
groupadd
The groupadd command creates new groups. For example:
groupadd developers
This creates a group named 'developers'.
Do You Know?
You can specify the user's UID and GID when creating a user for better control over system resources.
Managing Passwords and Permissions
passwd
The passwd command allows you to change passwords. You can change your own password using passwd, or change another user's password using sudo passwd username.
passwd john
chage
The chage command is used to manage password expiry settings. You can use it to set the minimum and maximum password age.
chage -m 7 -M 90 john
This sets the minimum password age to 7 days and the maximum to 90 days for user 'john'.
Important Note
Always follow your organization's security policies when setting password expiry policies.
Avoid This
Avoid using weak or easily guessable passwords.
Hands-on: Configuring User Roles and Access
Let's configure user roles and access. This involves assigning users to groups and granting permissions using chmod and chown commands. For example, we will add the user 'john' to the 'developers' group:
usermod -a -G developers john
This adds user 'john' to the 'developers' group without removing him from any existing groups.
Summary
- Learned how to create users and groups using
useraddandgroupadd. - Understood how to manage passwords using
passwdand password expiry usingchage. - Gained practical experience in configuring user roles and access control.