💳 ATM Management System (C Language)

The objective of this project is to demonstrate your ability to apply programming logic in the C language and adapt to an existing codebase by implementing new features and fixing existing issues. You are given a partially implemented ATM management system. Your task is to add the missing features and ensure proper file-based persistence and functionality.

1. 🧾 Registration

   • Users can register with a unique username (duplicates are not allowed).
   • User data is stored in database.db.

2. 🔐 Login

   • Users can log in to access account operations securely.

3. 🔄 Update Account Information

   • Users can update the country or phone number of an account.
   • Prompts for account id and field to update.
   • All changes are written back to database.db.

4. 🔍 Check Account Details

   • Users can retrieve information for a single account using its id.
   • Interest is displayed based on account type:
     • savings: 7%
     • fixed01: 4%
     • fixed02: 5%
     • fixed03: 8%
     • current: No interest

5. 💸 Make Transactions

   • Supports withdrawals and deposits for eligible accounts.
   • ❌ Transactions are not allowed for fixed-term accounts.

6. 🗑 Remove Account

   • Allows users to delete their own accounts.
   • Changes are persisted in database.db.

7. 🔁 Transfer Ownership

   • Users can transfer ownership of an account to another registered user.
   • Validates both accounts and updates ownership in the database.

.
├── data
│   └── database.db           # Stores all user and account data
└── src
    ├── auth.c                # Handles login and registration
    ├── funcs.c               # Core functionality for account operations
    ├── header.h              # Shared declarations
    ├── header.h.gch          # Precompiled header (can be ignored or regenerated)
    ├── main.c                # Program entry point
    ├── manageDB.c            # File/database handling
    └── system.c              # System UI and navigation logic

To compile the project, run:

gcc src/*.c -l sqlite3 -o atm

To execute:

./atm

• All data is stored in a single file: data/database.db.

Feel free to enhance this project further by adding encryption, a GUI, or additional validations.