Variables & Arguments – Storing Secrets Like a Ninja!

Ah, young cyber warrior! 🥷 It is time to unlock the power of variables – the scrolls of wisdom that hold information inside your scripts. You will also learn arguments, the secret messages passed between commands. Master this, and you'll control the command line like a true ninja! ⚔️

The Secret of Variables

A variable is like a hidden scroll 🏯 that stores information for later use.

How to create a variable?

#!/bin/bash

# Declare a secret variable
ninja_name="Shadow Blade"

# Use the secret
echo "Welcome, $ninja_name! 🥷"

💡 Notice the $ before the variable name when using it! Forget $ and your script won’t recognize the variable (just like a ninja without a mask 🏴‍☠️).

The Power of Arguments – Passing Secret Messages

Arguments allow you to send secret data to a script. 🤫

Example: Passing a name when running a script

#!/bin/bash

echo "Welcome, $1! 🥷"
echo "You have been chosen for a secret mission!"

How to run it?

./my_noob_script.sh Hattori

🛡 Output:

Welcome, Hattori! 🥷
You have been chosen for a secret mission!

Special Argument Variables

Symbol	Meaning
$1, $2, $3	Arguments passed to the script
$0	The script name itself
$#	Number of arguments given
$@	All arguments as a list
$?	Exit status of the last command

💡 Think of arguments as scrolls delivered to your script by secret ninja messengers. 🏯📜

Interactive Scripts – Talking to the Ninja

Instead of passing arguments, you can ask for input during script execution.

Example: Taking user input

#!/bin/bash

echo "Enter your ninja name: "
read ninja_name

echo "Ah, welcome $ninja_name! Your training begins now! 🥷⚔️"

💡 The read command is like a wise old master waiting for your response. Answer wisely! 😎

Secret Mission – Test Your Knowledge

Try modifying your script to:

✅ Ask the user for their favorite Linux command

✅ Print out how many arguments were passed to the script

✅ Create a random password generator using $RANDOM