MODULE 1 — INTRODUCTION TO SHELL SCRIPTING

Lesson 1: What Is Shell? What Is Bash?

A shell is a command interpreter in Linux. Bash is the most widely used.

#!/bin/bash
echo "Hello World!"

Lesson 2: Variables

name="Ved"
echo "Hello $name"

Lesson 3: User Input

read -p "Enter city: " city
echo "You are from $city"

Lesson 4: Conditions

ping -c 1 google.com &> /dev/null

if [ $? -eq 0 ]; then
  echo "Internet OK"
else
  echo "No Internet"
fi

Lesson 5: File Checks

if [ -f /etc/passwd ]; then
  echo "File exists"
fi

MODULE 2 — INTERMEDIATE AUTOMATION

Lesson 6: Loops

services=("nginx" "sshd")

for s in "${services[@]}"; do
  systemctl restart $s
done

Lesson 7: Log Analysis

grep "Failed password" /var/log/auth.log | awk '{print $11}' | uniq -c

Lesson 8: Backup Automation

src="/home/ved/docs"
dest="/backup/docs_$(date +%F).tar.gz"

tar -czf $dest $src

Lesson 9: Cron Jobs

0 2 * * * /scripts/backup.sh

Lesson 10: Menu Driven Tools

echo "1) Disk"
echo "2) Memory"
read choice

case $choice in
 1) df -h ;;
 2) free -h ;;
esac

MODULE 3 — ADVANCED SHELL SCRIPTING

Lesson 11: Functions

check_service() {
  systemctl is-active $1
}
check_service nginx

Lesson 12: Error Handling

set -euo pipefail
trap 'echo "Error at line $LINENO"' ERR

Lesson 13: Debugging

bash -x script.sh

Lesson 14: Arrays

servers=("node1" "node2")
for s in "${servers[@]}"; do
  ssh $s uptime
done

Lesson 15: JSON Parsing (DevOps)

curl -s https://api.github.com/users/ved | jq '.public_repos'

Lesson 16: Kubernetes Automation

kubectl get pods -A | grep "$1"

Lesson 17: Parallel Execution

parallel -j 5 ping -c 1 ::: server1 server2 server3

Lesson 18: Logging

log=/var/log/myscript.log
echo "$(date) - Started" >> $log

Lesson 19: Email Alerts

echo "Disk Alert" | mail -s "Warning" admin@example.com

MODULE 4 — REAL‑WORLD PROJECTS

Project 1: Server Health Dashboard

• CPU usage
• Memory
• Disk
• Top processes

Project 2: Log Analyzer

• Detect failed logins
• Detect suspicious IPs
• 500 error detection
• Export to CSV

Project 3: CI/CD Deployment Script

• Build Docker
• Push to registry
• Restart Kubernetes deployment

Project 4: Cloud Server Setup Script

• User creation
• SSH key automation
• Firewall setup
• Package installation

Project 5: Backup + Restore Automation

• Daily backup
• Encryption
• Upload to AWS S3
• Restore function

MODULE 5 — CHEAT SHEETS

Conditions

[ -f file ]
[ -d dir ]
[ -n "$x" ]
[ $a -eq $b ]

Loops

for i in {1..10}; do
for f in *.log; do

Useful Tools

• awk
• sed
• grep
• curl
• jq