Retail Management System (C)

A final project for the Advanced Programming Laboratory. This application is a console-based management system designed to handle the core operations of a retail business, including inventory tracking, employee permissions, customer relationships, and transaction logging.

📖 Description

This system allows a business to manage its three main pillars: Items, Employees, and Customers. It utilizes persistent storage to save data between sessions, ensuring that inventory levels and customer databases remain up to date.

The project demonstrates advanced C programming concepts, specifically dynamic memory management using Linked Lists and mixed file handling (Text & Binary).

🚀 Key Features

1. Employee Management (RBAC)

The system implements a Role-Based Access Control system with three permission levels:

• Admin (Level 1): Full access to all features, including adding/removing employees.
• Employee (Level 2): Can manage items/customers and process sales/returns.
• Practitioner (Level 3): Read-only access to search/view data and add new entries.
• Security: Includes a login system with a 3-attempt lockout mechanism.

2. Inventory Control

• Binary Storage: Items are stored in binary files for efficiency.
• Smart Sorting: The inventory is maintained as a Linked List, automatically sorted by Item ID.
• Attributes: Tracks Item ID, Name, Category, Price, Quantity, and specific attributes like Kosher Status.
• Search: Supports searching by ID or Name.

3. Customer CRM

• Sorted Database: Customer lists are automatically sorted by their Join Date.
• Purchase History: Tracks customer transactions and allows employees to view purchase history.
• Management: Efficient addition, removal, and searching of customer records.

4. System Logging

A comprehensive log.txt file automatically records all system activities with timestamps, including:

• User Logins/Logouts.
• Sales and Returns.
• Item/Customer updates.
• System Errors.

🛠️ Technical Implementation

• Language: C
• Data Structures: Singly Linked Lists (used for Employees, Customers, and Items) to allow dynamic memory allocation.
• File I/O:
  • items.bin: Binary file for inventory data.
  • customers.txt: Text file for customer data.
  • f_employee.txt: Text file for employee credentials.
  • log.txt: Text file for the audit trail.

📦 How to Run

1. Clone the repository.
2. Compile the source files using a C compiler (e.g., GCC):

   gcc main.c employees.c customers.c items.c log.c menu.c -o system.exe

3. Run the executable:

   ./system.exe

4. First Run: If no employee file exists, the system will create a default Admin account:
   • User: admin
   • Password: 12345678

👥 Authors

• Adam Korsunski (ID: 207803933)
• Nadav Rogers (ID: 326301520)