Linux systems allow multiple users, and managing these users is an important administrative task. Two essential commands for this are useradd (to create users) and userdel (to delete users).

1. useradd Command

The useradd command is used to create a new user account in Linux.

Basic Syntax

useradd [options] username

Common Uses

1. Create a new user

useradd john

2. Create a user with a home directory

Some systems create it automatically; if not, use:

useradd -m john

3. Set a custom home directory

useradd -d /custom/home/path john

4. Assign a user to a specific group

useradd -g developers john

5. Specify login shell

useradd -s /bin/bash john

6. Set account expiration date

useradd -e 2025-12-31 john

2. userdel Command

The userdel command is used to delete a user account from the system.

Basic Syntax

userdel [options] username

Common Uses

1. Delete a user account

userdel john

2. Delete a user along with their home directory and mail

userdel -r john

This removes:

• Home folder

• Mail spool

• User account details

3. Force delete a user even if logged in

userdel -f john

Files Affected During User Creation and Deletion

When using useradd, Linux updates:

• /etc/passwd

• /etc/shadow

• /etc/group

• /etc/gshadow

When using userdel, Linux removes or updates:

• User entry in system files

• Home directory (if -r used)

Summary