C++ File System Implementation

A complete implementation of a simple, Unix-like file system on a simulated disk.

🚀 Features

✅ Fully Implemented Commands

• mkdir <directory> - Create empty subdirectory
• ls - List directory contents (directories show with /)
• cd <directory> - Change to specified subdirectory
• home - Switch to root directory
• rmdir <directory> - Remove empty subdirectory
• create <filename> - Create empty file
• append <filename> <data> - Append data to file
• stat <name> - Display file/directory statistics
• cat <filename> - Print file contents
• tail <filename> <n> - Print last n bytes of file
• rm <filename> - Remove file

🔧 Advanced Features

• Multi-block file support - Files can span multiple 128-byte blocks
• Smart block allocation - Fills last block before allocating new ones
• Data persistence - File system state persists across sessions
• Comprehensive error handling - All required error messages implemented
• Efficient resource management - Proper cleanup and block reclamation

🏗️ Architecture

The project follows a layered architecture:

Shell (CLI) → FileSys (Commands) → BasicFileSys (Low-level) → Disk (Storage)

Block Structure

• Block Size: 128 bytes
• Total Blocks: 1,024 (0-1023)
• Block Types:
  • Block 0: Superblock (bitmap)
  • Block 1: Root directory
  • Other blocks: Dynamic allocation

Data Structures

• Directory Block: Magic number + entry count + name/block pairs
• Inode Block: Magic number + file size + data block pointers
• Data Block: Raw file data (128 bytes)

📋 Requirements

• Compiler: C++ compatible compiler (g++, clang++)
• Make: GNU Make
• Platform: Linux/Unix

🚀 Quick Start

1. Clone the Repository

git clone https://github.com/Shan533/C-File-System.git
cd C-File-System

2. Navigate to Source Directory

cd "file system skeleton code"

3. Build the Project

make

4. Run the File System

# Interactive mode
./filesys

# Script mode
./filesys -s test_script.txt

📖 Usage Examples

Basic Operations

# Create and navigate directories
mkdir testdir
cd testdir
ls
home

# Create and manipulate files
create myfile
append myfile "Hello, World!"
cat myfile
stat myfile
tail myfile 5

# Clean up
rm myfile
cd ..
rmdir testdir

Multi-block File Example

# Create a large file that spans multiple blocks
create bigfile
append bigfile "This is a long string that will exceed 128 bytes and require multiple blocks to store properly in our file system implementation."
stat bigfile
cat bigfile

🧪 Testing

The project includes comprehensive test scripts:

• test_script.txt - Basic functionality test
• test_large_files.txt - Multi-block file testing
• test_edge_cases.txt - Edge case testing
• test_persistence1.txt - Persistence testing
• test_newline.txt - Special character handling

Run Tests

# Run basic test
./filesys -s test_script.txt

# Run large file test
./filesys -s test_large_files.txt

# Run edge case test
./filesys -s test_edge_cases.txt