Section 1: Getting Started with Shell Scripting

Lesson 1: Creating Your First Shell Script

Let's dive into creating a simple "Hello, World!" script and make it executable.

1.1 Writing a Simple "Hello, World!" Script 

#!/bin/bash

# This is a simple "Hello, World!" script

echo "Hello, World!"

1.2 Making the Script Executable

Make the script executable using the chmod command.

chmod +x hello_world.sh

Now, you can run the script: 

./hello_world.sh

This script uses echo to print the "Hello, World!" message to the terminal.

Lesson 2: Shell Scripting Basics

Understanding basic concepts like comments, shebang, variables, and data types is crucial for effective shell scripting.

2.1 Comments and Shebang (#!/bin/bash)

Comments in a script provide explanations for humans but are ignored by the interpreter. 

#!/bin/bash

# This is a comment

echo "Script with a comment"

2.2 Variables and Data Types

Shell scripts support simple variable assignments without explicit data types.

#!/bin/bash

# Variable assignment

name="John"

age=30

# Displaying variables

echo "Name: $name"

echo "Age: $age"

Lesson 3: Input and Output in Shell Scripts

Interacting with users through input and displaying output are fundamental operations in shell scripting.

3.1 Reading User Input

#!/bin/bash

# Reading user input

echo -n "Enter your name: "

read name

echo "Hello, $name!"

3.2 Displaying Output to the Terminal 

#!/bin/bash

# Displaying output to the terminal

echo "This is a message to the terminal"

These examples cover the basics of shell scripting, including creating your first script, making it executable, understanding script structure, and handling input and output. As we progress, we'll explore more advanced scripting techniques and practical applications.