Enigma Machine C++ Simulator

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A command-line interface (CLI) simulator for the Enigma M3 encryption machine from World War 2, written in modern C++.

⏩ Features

• Complete Enigma M3 simulation with rotors (I-V), reflectors (A, B, C), and a configurable plugboard.

• Dual-Mode Operation: Functions as both an interactive menu and a command-line pipeline tool.

• Full I/O Support: Reads from stdin or files, writes to stdout or files, and works perfectly with pipes (|).

• Full Configuration: All machine settings are controllable via command-line flags (rotors, positions, reflector, and plugboard).

• Robust Validation: Protects against invalid machine configurations (e.g., incorrect rotor count, non-alphabetic positions).

• Step-by-Step Mode: A special feature in the interactive menu to visualize the character's path during encryption.

🔨 Building from Source

Required

• git (for cloning and FetchContent)
• cmake (version 3.14 or higher)
• A C++17 compliant compiler (e.g., g++, Clang, MSVC)

Instructions

# 1. Cloning repository
git clone https://github.com/devbrunofernandes/enigma.git
cd enigma

# 2. Creating build directory
mkdir build && cd build

# 3. Cmake config
# This will automatically download cxxopts dependency.
cmake ..

# 4. Building
cmake --build .

🔌 Usage

This simulator can run in two distinct modes, depending on how it's launched.

Interactive Mode

Starts an interactive menu that guides the user through setting up the Enigma machine and encrypting text.

How to run:

./enigma_machine

Use Case: Ideal for learning how the machine works, testing configurations, or using the step-by-step visualizer.

Argument (Pipeline) Mode

Runs as a command-line filter, processing all input from stdin or a file and printing the result to stdout or a file.

How to run:

• Pass any command-line argument (like -h or -f).

• Pipe (|) input to it.

• Redirect (>) output from it.

Use Case: Designed for scripting and integrating with other command-line tools in a Unix-like pipeline. Also for processing text files.

🖥️ Command-Line Examples