Demo Managing User Accounts

In this lesson you’ll learn how to create, modify, and delete Linux user accounts from the command line. We’ll also show how to verify the changes by inspecting system files and using commands like id, getent, and passwd -S. By the end you’ll understand the common user-management commands (useradd, usermod, userdel) and the system changes they produce. Note: these examples assume you are running as the root user. If you are not root, prefix the commands with sudo. Resources:

useradd, usermod, userdel: useradd(8) / usermod(8) / userdel(8)
Check groups and passwd entries: getent (see getent passwd, getent group)

Verify accounts and system files

Use these commands to inspect accounts and groups:

Show user identity and groups:

id <username>

Lookup user entry in system databases (works with NSS like LDAP):

getent passwd <username>
getent group <groupname>

Check /etc/passwd and /etc/group directly (local files):

grep '^<username>:' /etc/passwd
grep '^<groupname>:' /etc/group

Create users

Create a basic user user1 (no home by default on some distros):

useradd user1

Verify the account and its primary group:

id user1
getent passwd user1

Expected sample id output (UID/GID numbers vary):

uid=1005(user1) gid=1005(user1) groups=1005(user1)

Create user2 with a custom home directory and ensure the home is created (-m and -d):

useradd -m -d /custom_home/user2 user2

Verify:

id user2
ls -ld /custom_home/user2

Create user3 with a specific UID:

useradd -u 1050 -m user3
id user3

Expected:

uid=1050(user3) gid=1050(user3) groups=1050(user3)

Create a non-login/system-style account user4 by setting the shell to /sbin/nologin:

useradd -m -s /sbin/nologin user4
id user4

Create user5 with an existing primary group student (the student group must already exist):

useradd -m -g student user5
id user5

Expected (if student has GID 1000):

uid=1006(user5) gid=1000(student) groups=1000(student)

Create user6 and add it to the wheel group as a supplementary group:

useradd -m -G wheel user6
id user6
getent group wheel

Expected output showing wheel membership (UID/GID numbers may differ):

uid=1007(user6) gid=1007(user6) groups=1007(user6),10(wheel)

Modify users

Use usermod to change existing accounts.

Rename user1 to newuser1:

usermod -l newuser1 user1
id newuser1

Note: renaming a user does not automatically rename the home directory. To rename the account and move its home directory, include -d and -m:

usermod -l newuser1 -d /home/newuser1 -m user1

Add user2 to the wheel group without removing existing supplementary groups (append with -aG):

usermod -aG wheel user2
id user2

Change the login shell for user5 to /bin/bash:

usermod -s /bin/bash user5
getent passwd user5

Lock user4 to disable password-based logins:

usermod -L user4
# On many distributions you can inspect account status:
passwd -S user4

Expected passwd -S output after locking (format varies by distro):

user4 L 01/01/1970 0 99999 7 -1 (Password locked.)

Provide default files for new users

Files in /etc/skel/ are copied into new users’ home directories when you create homes with useradd -m.

Create a welcome file in /etc/skel/:

echo "Welcome to the system!" > /etc/skel/welcome
chmod 644 /etc/skel/welcome

Create a new user user7 to test that the welcome file is copied:

useradd -m user7
ls -l /home/user7/welcome
cat /home/user7/welcome

You should see /home/user7/welcome and the message you added.

Delete users

Delete user4 (removes only the user account, not the home directory):

userdel user4

Delete user5 and remove its home directory and mail spool (-r):

userdel -r user5

Confirm deletion by checking the passwd database:

getent passwd user4 || echo "user4 not found"
getent passwd user5 || echo "user5 not found"

Quick reference — common options

Command	Option	Purpose	Example
`useradd`	`-m`	Create the user’s home directory	`useradd -m user7`
`useradd`	`-d /path`	Set custom home directory	`useradd -m -d /custom_home/user2 user2`
`useradd`	`-u UID`	Specify numeric UID	`useradd -u 1050 -m user3`
`useradd`	`-s /bin/sh`	Set login shell	`useradd -m -s /sbin/nologin user4`
`useradd`	`-g group`	Primary group (group must exist)	`useradd -m -g student user5`
`useradd`	`-G group[,..]`	Supplementary groups	`useradd -m -G wheel user6`
`usermod`	`-l newname`	Rename account	`usermod -l newuser1 user1`
`usermod`	`-d /newhome -m`	Move and update home directory	`usermod -d /home/newuser1 -m user1`
`usermod`	`-aG group`	Append supplementary group(s)	`usermod -aG wheel user2`
`usermod`	`-s /bin/bash`	Change login shell	`usermod -s /bin/bash user5`
`usermod`	`-L`	Lock account (disable password login)	`usermod -L user4`
`userdel`	`-r`	Remove user and home/mail spools	`userdel -r user5`

Summary

useradd — create user accounts. Useful options: -m, -d, -u, -s, -g, -G.
usermod — modify existing accounts. Common options: -l, -d -m, -s, -aG, -L.
userdel — remove accounts; add -r to delete home directories and mail spools.
Put default files in /etc/skel/ to have them copied into new users’ homes when using useradd -m.
Verify accounts with id, getent passwd, getent group, or by inspecting /etc/passwd and /etc/group.

Always ensure any groups you reference (for example student or wheel) exist before assigning them as primary or supplementary groups. Use getent group <groupname> to check.

Introduction

Working with the Command Line

File Management

Working with Text Files

Output Redirection

User Management

Linux Permissions

Enhanced Command Line

Storage Management

Managing Services

Controlling the Boot Process

Scheduling Future Tasks

Working with Logs

Installing Software

Process Management & Tuning

Managing Network Configuration and Security

SELinux

Configuring SSH

Demo Managing User Accounts

Verify accounts and system files

Create users

Modify users

Provide default files for new users

Delete users

Quick reference — common options

Summary

Watch Video

​Verify accounts and system files

​Create users

​Modify users

​Provide default files for new users

​Delete users

​Quick reference — common options

​Summary

Watch Video

Verify accounts and system files

Create users

Modify users

Provide default files for new users

Delete users

Quick reference — common options

Summary