Inventory Management System in C

A robust console-based Inventory Management System developed in C with file handling, data structures, and a menu-driven interface for managing products, stock levels, and sales records.

📋 Table of Contents

• Features
• Project Structure
• Prerequisites
• Installation
• Compilation
• Usage
• File Format
• Technology Stack
• Author
• License

✨ Features

Product Management

• ✅ Add New Product - Add products with ID, name, category, price, quantity, and reorder level
• ✅ View All Products - Display all products in a tabular format
• ✅ Search Product - Search products by ID
• ✅ Update Quantity - Update product stock levels
• ✅ Update Price - Modify product pricing
• ✅ Delete Product - Remove products from inventory
• ✅ Check Low Stock - Alert when stock falls below reorder level

Inventory Management

• ✅ View Inventory Status - Check total products and inventory value
• ✅ Low Stock Alert - Real-time warnings for products below reorder level
• ✅ Total Inventory Value - Calculate total worth of all products
• ✅ Product Listing - View all products with details

Sales Management

• ✅ Record Sale - Log product sales with automatic stock deduction
• ✅ Sales Report - View detailed sales history with revenue calculation
• ✅ Automatic Stock Update - Inventory updates automatically on sale
• ✅ Sale Tracking - Each sale has unique ID and timestamp

Data Management

• ✅ File Persistence - Data saved to text files
• ✅ Auto-Load Data - Load existing inventory on startup
• ✅ Cross-Platform - Works on Windows, Linux, and macOS
• ✅ Data Validation - Input validation for all operations

📁 Project Structure

Inventory-Management-System-in-C/
├── headers/
│   ├── product.h           # Product structure and operations
│   ├── inventory.h         # Inventory management functions
│   └── file_handler.h      # File I/O operations
├── src/
│   ├── main.c              # Main application with menu system
│   ├── product.c           # Product implementation
│   ├── inventory.c         # Inventory implementation
│   └── file_handler.c      # File handling implementation
├── data/
│   ├── products.txt        # Products storage
│   └── sales.txt           # Sales records
├── README.md               # Project documentation
├── LICENSE                 # MIT License
├── .gitignore              # Git ignore rules
└── Makefile                # Build configuration

🔧 Prerequisites

• GCC Compiler (gcc)
• Make utility
• C99 Standard or later
• Linux/Unix/Windows with terminal access

Installation

For Linux/macOS:

# Install GCC and Make
sudo apt-get install build-essential    # Ubuntu/Debian
brew install gcc make                   # macOS

For Windows:

• Install MinGW or TDM-GCC
• Or use WSL (Windows Subsystem for Linux)

📦 Compilation

Option 1: Using Makefile (Recommended)

# Navigate to project directory
cd Inventory-Management-System-in-C

# Compile the project
make

# Or compile and run directly
make run

Option 2: Manual Compilation

# Create object files
gcc -Wall -Wextra -std=c99 -Iheaders -c src/main.c -o src/main.o
gcc -Wall -Wextra -std=c99 -Iheaders -c src/product.c -o src/product.o
gcc -Wall -Wextra -std=c99 -Iheaders -c src/inventory.c -o src/inventory.o
gcc -Wall -Wextra -std=c99 -Iheaders -c src/file_handler.c -o src/file_handler.o

# Link and create executable
gcc -o inventory src/main.o src/product.o src/inventory.o src/file_handler.o

Option 3: Single Command

gcc -Wall -Wextra -std=c99 -Iheaders -o inventory src/*.c

🚀 Usage

Run the Application

./inventory

Main Menu

╔════════════════════════════════════════════╗
║   INVENTORY MANAGEMENT SYSTEM (C)         ║
║   Version 1.0                             ║
╚════════════════════════════════════════════╝

╔════════════════════════════════════════════╗
║          MAIN MENU                        ║
╠════════════════════════════════════════════╣
║ 1. Product Management                      ║
║ 2. Inventory Management                    ║
║ 3. Sales Management                        ║
║ 4. Save & Exit                             ║
╚════════════════════════════════════════════╝

Example Workflow

1. Add a Product:

   • Select: 1 (Product Management) → 1 (Add New Product)
   • Enter Product ID: 101
   • Enter Name: Laptop
   • Enter Category: Electronics
   • Enter Price: 50000
   • Enter Quantity: 10
   • Enter Reorder Level: 3

2. View All Products:

   • Select: 1 → 2 (View All Products)

3. Record a Sale:

   • Select: 3 (Sales Management) → 1 (Record New Sale)
   • Enter Product ID: 101
   • Enter Quantity: 2

4. View Sales Report:

   • Select: 3 → 2 (View Sales Report)

5. Check Inventory Status:

   • Select: 2 (Inventory Management) → 1 (View Inventory Status)

6. Save & Exit:

   • Select: 4 (Save & Exit)

📄 File Format

products.txt Format

ProductID|ProductName|Category|Price|Quantity|ReorderLevel
101|Laptop|Electronics|50000|10|3
102|Mouse|Electronics|500|50|10
103|Keyboard|Electronics|2000|25|5

sales.txt Format

SaleID|ProductID|Quantity|TotalAmount|Date&Time
1000|101|2|100000|2026-07-11 15:30:45
1001|102|5|2500|2026-07-11 15:35:20

🏗️ Technology Stack

• Language: C (C99 Standard)
• Paradigm: Procedural Programming
• File Format: Text files (pipe-delimited)
• Build System: Make
• Compiler: GCC
• Platform: Cross-platform (Linux, macOS, Windows)

📊 Key Data Structures

Product Structure

typedef struct {
    int productID;
    char name[50];
    char category[30];
    float price;
    int quantity;
    int reorderLevel;
} Product;

Inventory Structure

typedef struct {
    Product products[100];
    int totalProducts;
} Inventory;

Sale Structure

typedef struct {
    int saleID;
    int productID;
    int quantity;
    float totalAmount;
    char date[20];
} Sale;

🎯 Functions Overview

Product Management

• addProduct() - Add new product
• displayProduct() - Show single product
• displayAllProducts() - Show all products
• findProductByID() - Search by ID
• updateProductQuantity() - Update stock
• updateProductPrice() - Update price
• deleteProduct() - Remove product
• checkLowStock() - Stock alerts

Inventory Management

• initializeInventory() - Initialize
• displayInventoryStatus() - Show status
• getInventoryValue() - Calculate value
• displayLowStockAlert() - Show alerts

Sales Management

• recordSale() - Record sale
• displaySalesReport() - Show report

File Operations

• saveProductsToFile() - Save products
• loadProductsFromFile() - Load products
• saveSaleToFile() - Save sale
• loadSalesFromFile() - Load sales

🛠️ Makefile Commands

make          # Compile the project
make run      # Compile and run
make clean    # Remove build files
make rebuild  # Clean and rebuild
make help     # Show all commands

🐛 Troubleshooting

Issue: "gcc not found"

Solution: Install GCC compiler for your OS

Issue: "Permission denied" when running

Solution: Make file executable

chmod +x inventory

Issue: "data directory not found"

Solution: The program creates it automatically. If not, manually create:

mkdir -p data

Issue: "File not found" error

Solution: Ensure you run from the project root directory

📝 Sample Test Cases

1. Add Products → View → Search
2. Update Quantity → Record Sale → Verify Stock
3. View Sales Report → Check Revenue
4. Low Stock Alert → Reorder Check
5. Save Data → Restart → Load Data

🎓 Learning Outcomes

• Proficiency in C programming
• Understanding of data structures (structs, arrays)
• File I/O operations in C
• Menu-driven application design
• Real-world business logic implementation
• Cross-platform development
• Build system usage (Makefile)
• Software architecture and modularity

🚀 Future Enhancements

• Database integration (SQLite)
• User authentication
• Advanced reporting (PDF/CSV export)
• Graphical UI (GTK+/Qt)
• Multi-user support
• Network capability
• Backup/Restore feature
• Data encryption

🤝 Contributing

Contributions are welcome! Feel free to:

1. Fork the repository
2. Create a feature branch
3. Submit a pull request

📧 Contact

Author: Deepak Kumar
GitHub: @deepaksaranay
Email: deepakkumar.dar@gmail.com
LinkedIn: linkedin.com/in/deepak-kumar-083448115

📄 License

This project is licensed under the MIT License - see LICENSE file for details.

⭐ Acknowledgments

• C programming best practices
• Data structure design patterns
• File handling techniques
• Cross-platform development

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Made with ❤️ by Deepak Kumar

Last Updated: July 2026