Atul Maurya - Blogs

1. What is Bash?

Bash = Bourne Again SHell

It is like the upgraded version of sh — faster, smarter, and filled with modern features.

Think of it like this:

sh = Old Nokia phone

bash = Modern Android phone

(more features, smoother to use)

Bash is the default shell on most Linux systems.

2. Why is Bash so popular?

Because it gives you:

Auto-complete (press TAB)

Command history (press ↑)

Colourful prompt

Arrays

Functions

Better scripting features

Easier for daily use

Works everywhere (almost)

This is why most Linux users use bash daily.

3. Where is Bash located?

Usually at: /bin/bash

Many scripts start with:

#!/bin/bash

→ This means “Run this using the Bash shell.”

5. Your First Bash Script

Create a file: hello.sh

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

Run it:

chmod +x hello.sh
./hello.sh

Output:

Hello from bash!

7. Bash Prompt (PS1) — Why You See Colored Text

The colorful part of your terminal

atul@host:~/folder$

is controlled by bash.

It shows:

your username

your computer name

your current folder

You can even customize the color.

8. When should YOU use Bash?

For daily terminal usage

Easiest and most comfortable.

For writing scripts with loops, arrays, logic

More powerful than sh.

For DevOps, automation, servers, tools

9. Story to Remember Bash Forever

Story to Remember Bash (Short):

If sh is the grandfather, then Bash is the smart grandson — fast, modern, remembers everything, and helps you quickly while still respecting sh.

👉 Bash = sh + superpowers. That’s why everyone uses it today.

Home work (Must go though these Features) For getting a basic Idea :

6. Bash Features You Will Actually Use :

Here are only the most useful features — explained simply.

1. Variables

name="Atul"
echo $name

2. Arrays (sh cannot do this)

fruits=("apple" "mango" "banana")
echo ${fruits[1]}   # mango

3. If condition

if [ $name = "Atul" ]; then
  echo "Hi Atul"
else
  echo "Not Atul"
fi

4. For loop

for i in 1 2 3; do
  echo $i
done

5. Command history

Press:

↑ arrow key

to see old commands.

6. Auto-completion

Type:

cd Doc

Now press TAB → becomes:

cd Documents/

B.) BASH (Bourne Again SHell):