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Jr Carreiro
Jr Carreiro

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🔴 Chapter 01 – Setting Up a Ruby Environment (Line by Line for Beginners

#hackingwithruby #offensivesecurity #appsec #mobilesec

Before we write any code, we need a place to work.
Think of this like setting up your workshop before you build a robot.

Let’s organize our tools and build the simplest thing we can:
a script that says "Hello, Hacker!"

🧰 What are we building?

We’re creating a Ruby project with:

  • 🗂️ Folders to keep things organized
  • 🔁 Logic we can reuse later
  • 🖥️ Scripts we can run from the terminal

🧃 Think of this like a kitchen:
You’ll have drawers (code) and buttons (scripts) that do things.

📦 Project Structure 

ruby/
└── Chapter 01 – Setting Up a Ruby Environment/
    ├── bin/
    │   └── hello_world.rb
    └── lib/
        └── hacking/
            └── core.rb
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💻 Installing Ruby

Choose the method for your OS:

✅ Option 1 – Using rbenv (Linux/macOS) 

sudo apt update && sudo apt install -y git curl build-essential libssl-dev libreadline-dev zlib1g-dev
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
cd ~/.rbenv && src/configure && make -C src
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init - bash)"' >> ~/.bashrc
source ~/.bashrc
git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
rbenv install 3.3.5
rbenv global 3.3.5
ruby -v
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✅ Option 2 – Using rvm (macOS or Linux) 

sudo apt install curl gpg
curl -sSL https://rvm.io/mpapis.asc | gpg --import -
\curl -sSL https://get.rvm.io | bash -s stable --ruby
source ~/.rvm/scripts/rvm
rvm install 3.3.5
rvm use 3.3.5 --default
ruby -v
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✅ Option 3 – Windows (RubyInstaller)

  1. Download from https://rubyinstaller.org
  2. Run installer (check "add to PATH")
  3. Open PowerShell or CMD: 
ruby -v
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📄 lib/hacking/core.rb 

module Hacking
  module Core
    def self.greet
      "Hello, Hacker! Ready to break things? 💥"
    end
  end
end
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📄 bin/hello_world.rb 

#!/usr/bin/env ruby
# frozen_string_literal: true

require_relative '../lib/hacking/core'

puts Hacking::Core.greet
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▶️ Run it! 

cd ruby/Chapter\ 01\ –\ Setting\ Up\ a\ Ruby\ Environment
ruby bin/hello_world.rb
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✅ Output:

Hello, Hacker! Ready to break things? 💥
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🧠 Final Recap

Concept What it means
rbenv / rvm / RubyInstaller Install Ruby safely
bin/ Where your scripts live
lib/ Where your logic lives
module Group of code
self.method Call a method directly
require_relative Load local file
puts Print message

✅ You now have:

  • Ruby installed (on any OS)
  • A clean project structure
  • Your first script up and running
  • The foundation for your Ruby offensive tools!

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