Linux Arithmetic Calculations

Introduction

Welcome to the year 2150, in a sprawling underground community beneath the megalopolis known as Neo-Babylon. As the surface of the planet became inhospitable, mankind has retreated into the earth's crust, building vast networks of interconnected living spaces, commerce hubs, and industrial sectors. In this new world, technology has progressed by leaps and bounds, but so has the complexity of its operations and the need for skilled operatives.

You are a member of the Resistance, a group of elite underground operatives fighting against the tyrannical super-corporations that control the heart of Neo-Babylon. Your mission today, should you choose to accept it, involves infiltrating the central computing nexus and cracking into its mainframe. To succeed, you will need to become a master of bc, the powerful Linux command-line calculator.

Only by mastering arithmetic calculations on the Linux system can you hope to navigate through the cryptographic barriers and unlock the secrets that will lead your band of rebels to a victorious uprising. This Lab will equip you with the knowledge to perform complex arithmetic computations and to script these operations, which are crucial for decoding the encrypted messages you'll encounter in the field.

Your journey into the Linux underground begins now!

Skills Graph

Getting Started with bc

In this step, we're going to explore the basics of bc. bc stands for Basic Calculator in Linux and it's a command-line utility that allows you to perform arithmetic operations.

At first, let's install bc on your system:

sudo apt-get update
sudo apt-get install bc

Start by creating a new script called simple_calc.sh in the ~/project directory:

cd ~/project
touch simple_calc.sh

Next, open the script in your favorite text editor and add the following content:

#!/bin/zsh

echo "20 + 5" | bc

This code will send a simple addition operation, 20 + 5, to bc and output the result.

Make the script executable:

chmod +x simple_calc.sh

Run the script:

./simple_calc.sh

You should see the output 25 displayed in the terminal.

Complex Expressions in bc

Now that you've seen how bc can handle a simple addition command, let's explore a more complex expression.

Create a new file named complex_calc.sh in the ~/project directory:

cd ~/project
touch complex_calc.sh

Add the following script to perform a series of operations and save the results in variables:

#!/bin/zsh

result=$(echo "scale=2; (10.5 * 4.2) - (5.5 / 2) + 3^2" | bc)
echo "Result: $result"

This script uses scale=2, which tells bc to use 2 decimal places for the answer. It then performs multiplication, division, and exponentiation, and combines them in a series of operations.

After saving the script, make it executable and run it:

chmod +x complex_calc.sh
./complex_calc.sh

The output should show the result of the complex expression.

Remember to observe how bc not only computes arithmetic expressions but also handles floating-point precision as per the scale setting.

Summary

In this lab, you have learned how to harness the bc utility for performing arithmetic calculations within Linux, which is a vital skill for the futuristic setting of your espionage and sabotage missions. As you progressed through the steps, we covered basic addition, later delving into more intricate expressions that included variables, scale management, and various operators.

Stepping into the shoes of a Resistance operative, you practiced these calculations not as mere academic exercises, but as essential parts of cracking security algorithms and decoding sensitive information against the oppressive regime. The necessity of learning through the context of real-world applications was realized as you encountered the complexity of bc in the shadows of Neo-Babylon.

Embrace the power of the Linux command line and the simplicity yet potency of bc, and take one more step towards overthrowing the overlords and leading your people to freedom. Good luck, agent.