README.md

🗄️ File Manager with Encryption / Decryption

A command-line tool that allows you to create, read, edit, delete, and list files — along with encrypting and decrypting them using an extended Caesar cipher.
Built entirely in C++ using only standard libraries.

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🚀 Features

📁 File Management

• Create new text files
• Read file contents
• Append text to existing files
• Delete files
• List files (Windows uses dir, Linux uses ls)

🔐 Encryption & Decryption

• Extended Caesar Cipher implementation
• Key-based dynamic shifting
• Supports:
  • Lowercase letters
  • Uppercase letters
  • Digits
  • Printable ASCII characters (33–126)
• Whitespace remains untouched
• Wrap-around logic for every character range

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🛠️ Tech Stack

• C++
• Standard Library (iostream, fstream, string)

No frameworks or external dependencies.

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📦 How It Works

1. File Operations Menu

Users can:

• Create File
• Read File
• Edit File
• Delete File
• List Files

2. Encryption / Decryption

The shift value is derived from the key:

Character handling:

• Alphabet → Rotated within alphabet
• Numbers → Rotated within 0–9
• Symbols → Rotated within ASCII 33–126
• Whitespace → Preserved
• Byte-by-byte processing

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📥 How to Run

Clone the repository

git clone https://github.com/<your-username>/<your-repo>.git

Compile

g++ File.cpp -o filemanager

Run

./filemanager

📌 Example Usage

Encrypt

Input  : input.txt
Output : encrypted.txt
Key    : mykey123

Decrypt

Use the same key to restore original contents.

Project Structure

File.cpp      → Source code
README.md     → Documentation