sudo for elevated privileges in Linux CLI - Mini Project: Build & Apply

Using sudo for Elevated Privileges

📖 Scenario: You are managing files on a Linux system. Some files need special permissions to be accessed or modified. You will learn how to use sudo to run commands with elevated privileges safely.

🎯 Goal: Learn to use sudo to list a protected directory, create a file in it, and then display the file's contents.

📋 What You'll Learn

Use the sudo command to run commands with elevated privileges

List the contents of a protected directory /root

Create a file called secret.txt inside /root using sudo

Write text into the file using sudo

Display the contents of the file using sudo

💡 Why This Matters

🌍 Real World

System administrators often need to run commands with elevated privileges to manage system files and settings securely.

💼 Career

Knowing how to use <code>sudo</code> is essential for Linux system administrators, DevOps engineers, and anyone managing servers or secure environments.

1

List the contents of the /root directory using sudo

Type the command sudo ls /root to list the contents of the /root directory, which requires elevated privileges.

Linux CLI

# Type the command to list /root directory contents with sudo
# Your code here

Hint

The sudo command lets you run commands as the superuser. Use it before ls /root to see inside the protected directory.

2

Create a file called secret.txt inside /root using sudo

Type the command sudo touch /root/secret.txt to create an empty file named secret.txt inside the /root directory.

Linux CLI

sudo ls /root
# Create an empty file /root/secret.txt using sudo
# Your code here

Hint

Use sudo touch /root/secret.txt to create the file with superuser rights.

3

Write the text Top Secret Data into /root/secret.txt using sudo

Type the command echo 'Top Secret Data' | sudo tee /root/secret.txt to write the text Top Secret Data into the file /root/secret.txt with elevated privileges.

Linux CLI

sudo ls /root
sudo touch /root/secret.txt
# Write 'Top Secret Data' into /root/secret.txt using sudo
# Your code here

Hint

Use echo to send text and sudo tee to write it into the file with superuser rights.

4

Display the contents of /root/secret.txt using sudo

Type the command sudo cat /root/secret.txt to display the contents of the file /root/secret.txt with elevated privileges.

Linux CLI

sudo ls /root
sudo touch /root/secret.txt
echo 'Top Secret Data' | sudo tee /root/secret.txt
# Display the contents of /root/secret.txt using sudo
# Your code here

Hint

Use sudo cat /root/secret.txt to read the file contents with superuser rights.

Practice

1. What is the main purpose of using sudo in Linux?

easy

A. To create a new user account

B. To switch to another user account permanently

C. To list files in a directory

D. To run commands with higher privileges than a normal user

Solution

1. Step 1: Understand what sudo does

   sudo allows a user to run commands with elevated privileges, usually root access.

2. Step 2: Compare options with sudo purpose

   Only To run commands with higher privileges than a normal user describes running commands with higher privileges, which matches sudo's main use.

3. Final Answer:

   To run commands with higher privileges than a normal user -> Option D

4. Quick Check:

   sudo = elevated privileges [OK]

Hint: sudo means run as superuser or admin [OK]

Common Mistakes:

• Confusing sudo with user switching commands
• Thinking sudo creates users
• Assuming sudo lists files

2. Which of the following is the correct syntax to run the command apt update with elevated privileges?

easy

A. sudo apt update

B. apt sudo update

C. sudo -u apt update

D. apt update sudo

Solution

1. Step 1: Recall the correct sudo syntax

   The correct syntax is sudo [command], so sudo apt update is valid.

2. Step 2: Check each option

   Options A, B, and D place sudo incorrectly or misuse flags.

3. Final Answer:

   sudo apt update -> Option A

4. Quick Check:

   sudo before command = correct syntax [OK]

Hint: Put sudo before the command to elevate it [OK]

Common Mistakes:

• Placing sudo after the command
• Using sudo with wrong flags
• Mixing sudo with user flags incorrectly

3. What will be the output of the command sudo whoami if run by a normal user?

medium

A. root

B. sudo

C. normal user name

D. Permission denied

Solution

1. Step 1: Understand what whoami does

   whoami prints the current user's name.

2. Step 2: Effect of sudo on whoami

   Running sudo whoami runs the command as root, so it prints root.

3. Final Answer:

   root -> Option A

4. Quick Check:

   sudo changes user to root for command [OK]

Hint: sudo runs command as root user [OK]

Common Mistakes:

• Expecting normal username output
• Thinking sudo prints 'sudo'
• Assuming permission denied without sudo

4. You try to run sudo apt-get update but get the error: sudo: command not found. What is the most likely cause?

medium

A. You typed the command incorrectly

B. You are not logged in as root

C. The sudo package is not installed or not in PATH

D. You need to use su instead of sudo

Solution

1. Step 1: Analyze the error message

   sudo: command not found means the system cannot find the sudo program.

2. Step 2: Identify common reasons

   This usually happens if sudo is not installed or its location is missing from the PATH environment variable.

3. Final Answer:

   The sudo package is not installed or not in PATH -> Option C

4. Quick Check:

   command not found = missing sudo or PATH [OK]

Hint: command not found means sudo missing or PATH wrong [OK]

Common Mistakes:

• Assuming user login affects sudo command presence
• Thinking command typo causes 'command not found'
• Confusing su and sudo usage errors

5. You want to run a script backup.sh that requires root permissions. Which command correctly runs it with sudo and ensures the script's environment variables are preserved?

hard

A. sudo ./backup.sh

B. sudo -E ./backup.sh

C. sudo -u root ./backup.sh

D. sudo --preserve-env=ALL ./backup.sh

Solution

1. Step 1: Understand environment preservation with sudo

   By default, sudo resets environment variables for security. The -E flag preserves the user's environment.

2. Step 2: Evaluate options for preserving environment

   sudo -E ./backup.sh uses -E which preserves environment variables. sudo --preserve-env=ALL ./backup.sh uses a longer form but --preserve-env=ALL is less common and may not be supported everywhere.

3. Final Answer:

   sudo -E ./backup.sh -> Option B

4. Quick Check:

   sudo -E preserves environment variables [OK]

Hint: Use sudo -E to keep environment variables [OK]

Common Mistakes:

• Forgetting environment variables reset by sudo
• Using sudo without -E loses variables
• Confusing -u root with environment preservation