📒 Address Book System (C Programming)

🚀 Overview

The Address Book System is a console-based application developed in C to store and manage contact details such as name, phone number, and email address. The application uses file handling to ensure data persistence using a CSV file.

This project demonstrates fundamental programming concepts including structures, modular programming, file handling, and input validation.

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✨ Features

• ➕ Add new contacts with validation
• 🔍 Search contacts by name, phone number, or email
• ✏️ Edit existing contact details
• ❌ Delete contacts from the system
• 📋 Display all contacts in alphabetical order
• 💾 Persistent storage using CSV file
• ⚠️ Input validation for data integrity
• 🔁 Handles duplicate entries and multiple matches
• 🧭 Menu-driven interface for easy navigation

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🛠️ Technologies Used

• C Programming
• Structures
• File Handling (CSV)
• Modular Programming

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📂 Project Structure

.
├── main.c
├── contact.c
├── contact.h
├── file.c
├── validation.c
├── address_book.csv
└── README.md

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⚙️ Functional Modules

📁 File Handling

• saveContactsToFile() – Saves contacts into CSV file
• loadContactsFromFile() – Loads contacts from CSV file

📋 Contact Management

• createContact() – Add new contacts
• searchContact() – Search contacts
• editContact() – Modify contact details
• deleteContact() – Remove contacts

🔎 Search Operations

• search_name()
• search_number()
• search_mail()

✅ Validation

• valname() – Validates name
• valnum() – Validates phone number
• valmail() – Validates email

✍️ Input Functions

• enter_name()
• enter_number()
• enter_email()

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⚠️ Challenges Faced

• Maintaining data consistency during edit and delete operations
• Preventing duplicate entries
• Handling invalid inputs and empty records
• Managing file pointers effectively

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📚 Learning Outcomes

• Improved understanding of file handling and data persistence
• Gained experience in modular coding and program structuring
• Learned defensive programming techniques
• Strengthened debugging and validation logic

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📌 Future Improvements

• Add GUI interface
• Support for more file formats
• Advanced search filters
• Integration with database systems

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🙌 Acknowledgment

Special thanks to mentors and learning resources that guided me during this project.