Kill Zombie Challenge

kill-zombie-challenge.md

🧟‍♂️ Kill the Zombie — Linux Process Challenge

Welcome to your 20-minute Linux shell mini-challenge!

🎯 Goal

Learn to:

• Launch background jobs (fake zombie-like processes)
• Identify and monitor running processes
• Kill them using kill, killall, or pkill
• Observe real CPU/MEM changes via top

---

🛠 How to Start

1. Give executable permission to both scripts:

   chmod +x spawn_zombies.sh monitor_top.sh

2. Run the zombie spawner:

   ./spawn_zombies.sh

3. Open a new terminal tab and monitor system resources:

   top

4. After attempting cleanup, run the monitor to compare system load:

   ./monitor_top.sh

---

✅ Your Task

• Locate processes using:

  ps aux | grep sleep
  top
  htop

• Kill them using:

  kill <PID>
  killall yes
  pkill tail

• Observe the drop in CPU/memory usage in top

---

📌 Bonus Challenges

• Can you killall all dummy jobs in one command?
• What’s the PID of the infinite while loop?
• Which process consumed the most CPU?
• What happens if you don’t & (background) a job?

---

💡 Useful Commands

Command	Description
jobs -l	Show running background jobs
ps aux	List all system processes
kill <PID>	Kill a process by PID
killall <name>	Kill all processes by name
top / htop	Monitor system resource usage live
pkill <name>	Kill process by name using pattern

---

🏁 Wrap-Up

This challenge simulates how we handle rogue or resource-hogging processes in production. You'll use these skills often when:

• Restarting broken services
• Automating cleanup tasks
• Managing cron jobs and daemons
• Debugging memory leaks and CPU spikes

✨ Bonus Tip: Always be cautious with kill -9. It's like the nuclear option. 🧨

---

Happy hunting! Let’s terminate those zombies! 🧟‍♀️💻

monitor_top.sh

#!/bin/bash
# monitor_top.sh - Snapshot system resource usage before & after challenge

echo "📊 CPU & Memory Snapshot BEFORE:"
top -b -n1 | head -15

echo -e "\\n⏳ Wait 10 seconds while you kill dummy jobs...\n"
sleep 10

echo "📊 CPU & Memory Snapshot AFTER:"
top -b -n1 | head -15

spawn_zombies.sh

#!/bin/bash
# 🧟‍♂️ spawn_zombies.sh - Simulate zombie-like jobs for kill practice

echo "🚀 Launching dummy background jobs..."

sleep 9999 &
yes > /dev/null &
tail -f /dev/null &
while true; do echo \"Still alive...\"; sleep 10; done &

echo "✅ 4 background jobs started:"
jobs -l

echo -e "\\n🧠 Challenge:"
echo "1. Use ps/top/htop to find all spawned zombie-like processes."
echo "2. Kill them individually or all together."
echo "3. Use 'top' to check CPU & memory before and after."

echo -e "\\n💡 Hints:"
echo "- Use 'ps aux | grep <pattern>'"
echo "- Use 'kill <PID>' or 'killall <name>'"
echo "- Watch top or htop side-by-side."

echo -e "\\n⚠️ Cleanup Reminder:"
echo "If you don't kill them, they will keep running until logout!"