top and htop (live monitoring) in Linux CLI - Mini Project: Build & Apply

Monitor System Processes with top and htop

📖 Scenario: You are a system administrator who needs to check the current running processes and system resource usage on a Linux server. You will use the top and htop commands to monitor CPU, memory, and process information live.

🎯 Goal: Learn how to use the top command to view live system process information and then install and run htop for a more user-friendly interactive monitoring experience.

📋 What You'll Learn

Use the top command to display live system processes

Install htop using the package manager

Run htop to view interactive process monitoring

Exit both top and htop properly

💡 Why This Matters

🌍 Real World

System administrators and DevOps engineers use <code>top</code> and <code>htop</code> daily to monitor server health and troubleshoot performance issues.

💼 Career

Knowing how to monitor live system processes is essential for maintaining reliable and efficient servers in any IT or DevOps role.

1

Run the top command to view live system processes

Open your terminal and type top to start live monitoring of system processes. Let it run for a few seconds to observe CPU and memory usage.

Linux CLI

# Type top and observe the output
# Your code here

Hint

The top command shows a live list of running processes and system resource usage. Just type top and press Enter.

2

Install htop for enhanced process monitoring

Use the package manager to install htop. If you are on Ubuntu or Debian, type sudo apt-get install htop. For CentOS or RHEL, use sudo yum install htop.

Linux CLI

top
# Install htop using the package manager
# Your code here

Hint

Use sudo apt-get install htop on Debian-based systems or sudo yum install htop on RedHat-based systems to install htop.

3

Run htop to view interactive process monitoring

After installing, type htop in the terminal to start the interactive process viewer. Notice the color-coded bars and easier navigation.

Linux CLI

top
sudo apt-get install htop
# Run htop to start interactive monitoring
# Your code here

Hint

Simply type htop and press Enter to launch the interactive process viewer.

4

Exit top and htop properly

To exit top or htop, press the q key on your keyboard. This will return you to the normal terminal prompt.

Linux CLI

top
sudo apt-get install htop
htop
# Press q to exit both top and htop
# Your code here

Hint

Pressing q quits the live monitoring tools and returns you to the command prompt.

Practice

1. What is the main purpose of the top command in Linux?

easy

A. To display live system and process information

B. To edit text files

C. To compile programs

D. To manage user accounts

Solution

1. Step 1: Understand the function of top

   The top command shows real-time information about system processes and resource usage.

2. Step 2: Compare with other options

   Options B, C, and D relate to different commands or tools, not top.

3. Final Answer:

   To display live system and process information -> Option A

4. Quick Check:

   top = live system info [OK]

Hint: Remember: top shows live system stats [OK]

Common Mistakes:

• Confusing top with text editors like nano
• Thinking top manages users
• Assuming top compiles code

2. Which of the following commands correctly starts htop in the terminal?

easy

A. start htop

B. htop -start

C. htop &

D. run htop

Solution

1. Step 1: Identify correct syntax to run htop

   The command htop runs the program; adding & runs it in background.

2. Step 2: Check other options for correctness

   Options B, C, and D are not valid Linux commands to start htop.

3. Final Answer:

   htop & -> Option C

4. Quick Check:

   Run htop with 'htop &' [OK]

Hint: Run htop by typing 'htop' or 'htop &' [OK]

Common Mistakes:

• Using invalid flags like -start
• Typing 'start htop' which is Windows style
• Using 'run htop' which is not a Linux command

3. You run top and see a process using 95% CPU. What does this indicate?

medium

A. The process is waiting for user input

B. The process is sleeping and not active

C. The process is stopped

D. The process is using most of the CPU power

Solution

1. Step 1: Interpret CPU usage in top

   High CPU percentage means the process is actively using CPU resources.

2. Step 2: Understand other states

   Sleeping or waiting processes use little CPU; stopped processes do not use CPU.

3. Final Answer:

   The process is using most of the CPU power -> Option D

4. Quick Check:

   High CPU% = active process [OK]

Hint: High CPU% means active process using CPU [OK]

Common Mistakes:

• Thinking high CPU means sleeping
• Confusing waiting with stopped
• Assuming stopped processes use CPU

4. You try to run htop but get: command not found. What should you do?

medium

A. Restart the computer

B. Install htop using the package manager

C. Run top instead

D. Check if you typed htop correctly

Solution

1. Step 1: Understand 'command not found' error

   This means htop is not installed or not in PATH.

2. Step 2: Fix by installing htop

   Use package manager like sudo apt install htop or sudo yum install htop to install.

3. Final Answer:

   Install htop using the package manager -> Option B

4. Quick Check:

   command not found = install missing tool [OK]

Hint: Install missing commands with package manager [OK]

Common Mistakes:

• Restarting without installing
• Ignoring the error and running top
• Not checking spelling before install

5. You want to find and kill the process using the most memory using htop. What steps should you follow?

hard

A. Sort by memory, select process, press F9 to kill

B. Sort by CPU, select process, press F10 to kill

C. Sort by PID, select process, press F3 to kill

D. Sort by user, select process, press F5 to kill

Solution

1. Step 1: Sort processes by memory usage in htop

   Press F6 or click the memory column to sort descending by memory.

2. Step 2: Select the top memory-consuming process and kill it

   Use arrow keys to select process, then press F9 to kill it.

3. Final Answer:

   Sort by memory, select process, press F9 to kill -> Option A

4. Quick Check:

   htop kill = sort mem + F9 [OK]

Hint: In htop, F9 kills selected process after sorting [OK]

Common Mistakes:

• Using wrong function keys to kill
• Sorting by CPU instead of memory
• Trying to kill by PID without selecting