🔐 Login & Registration System — CodeAlpha C++ Internship

A console-based Login and Registration System developed in C++ as part of the CodeAlpha C++ Programming Internship — Task 2.

The application provides a simple user authentication workflow where users can create an account, register a username and password, and later log in using their saved credentials. User information is stored in a local text file and checked during authentication.

📌 Project Overview

The Login & Registration System is designed to demonstrate the basic concepts behind user registration and authentication using C++.

The system allows users to:

Register a new username and password
Validate usernames and passwords
Detect duplicate usernames
Store registered credentials in a local file
Log in using previously registered credentials
Receive success and error messages
Exit the application through a simple menu

The project also includes a colored console interface and sound feedback for successful and unsuccessful operations.

🏢 CodeAlpha Internship

Internship: CodeAlpha C++ Programming Internship Task: Task 2 — Login and Registration System Language: C++ Application Type: Console Application Platform: Windows

✨ Main Features

📝 User Registration

Users can create an account by providing:

Username
Password

The registration process checks the entered information before saving the credentials.

👤 Username Validation

A username:

Cannot be empty
Can contain letters
Can contain numbers
Can contain underscores (_)
Cannot contain spaces
Cannot contain other special characters

Example of a valid username:

Maira_123

🔎 Duplicate Username Detection

Before creating a new account, the program checks users.txt to determine whether the username already exists.

If the username is already registered, the user is asked to choose another one.

🔑 Password Validation

The program requires passwords to contain at least 6 characters.

Minimum password length: 6 characters

🔐 Login Verification

During login, the system:

Takes the username.
Takes the password.
Opens the credentials file.
Searches for a matching username and password.
Displays the appropriate result.

🔊 Audio Feedback

The program uses Windows Beep() functionality to provide different sounds for:

Successful operations
Errors

🎨 Console Interface

The application uses colored console text to distinguish:

Menu options
Input prompts
Success messages
Error messages
Section headings

🔄 System Workflow

                    ┌─────────────────────┐
                    │       Start         │
                    └──────────┬──────────┘
                               │
                               ▼
                    ┌─────────────────────┐
                    │     Main Menu       │
                    └──────────┬──────────┘
                               │
                 ┌─────────────┼─────────────┐
                 ▼             ▼             ▼
            Register         Login          Exit
                 │             │
                 ▼             ▼
        Validate Username   Enter Credentials
                 │             │
                 ▼             ▼
        Check Duplicate     Read users.txt
                 │             │
                 ▼             ▼
        Validate Password   Verify Credentials
                 │             │
                 ▼       ┌─────┴─────┐
          Save to File    │           │
                 │      Match       No Match
                 │       │           │
                 ▼       ▼           ▼
        Registration    Success     Error
          Successful

📂 Credential Storage

Registered credentials are stored locally in:

users.txt

The program writes each username and password as a pair separated by a space.

Example structure:

username1 password123
username2 mypass456

During login, the program reads the stored username and password pairs and compares them with the credentials entered by the user.

⚠️ Security Consideration

This project is intended as an educational authentication system.

The current implementation stores passwords in plain text inside users.txt. Therefore, it should not be considered suitable for real-world authentication or production use.

A production-ready authentication system should use techniques such as:

Password hashing
Salting
Secure credential storage
Encrypted communication
Strong authentication policies
Proper access control

This project focuses on demonstrating the basic C++ implementation of registration, file handling, validation, and login verification.

🧩 Core Functions

The program is organized into separate functions for different responsibilities.

`validUsername()`

Checks whether the username follows the allowed character rules.

bool validUsername(string username)

`validPassword()`

Checks whether the password meets the minimum length requirement.

bool validPassword(string password)

`usernameExists()`

Searches users.txt to determine whether a username is already registered.

bool usernameExists(string username)

`registration()`

Handles the complete registration process, including validation and saving the new credentials.

void registration()

`login()`

Reads stored credentials and verifies the user's login information.

void login()

`setColor()`

Changes the Windows console text color.

void setColor(int color)

`successSound()` / `errorSound()`

Provide audio feedback for successful and unsuccessful actions.

🛠️ Technologies Used

Programming Language

C++

Libraries

#include <iostream>
#include <fstream>
#include <string>
#include <cctype>
#include <windows.h>

Important C++ Concepts

Functions
Strings
File handling
Input validation
Loops
Conditional statements
Boolean functions
Character validation
File streams
Console formatting
Windows API functions

🖥️ Application Menu

When the program starts, the user is presented with:

========================================
       LOGIN & REGISTRATION SYSTEM
========================================

1. Register
2. Login
3. Exit

Enter choice:

The user can select one of the three available operations.

📝 Registration Process

The registration workflow is:

Enter Username
      ↓
Validate Username
      ↓
Check Existing Username
      ↓
Enter Password
      ↓
Validate Password
      ↓
Save Credentials
      ↓
Registration Successful

If an invalid username or password is entered, the program displays an appropriate error message and asks for valid information.

🔓 Login Process

The login workflow is:

Enter Username
      ↓
Enter Password
      ↓
Open users.txt
      ↓
Search Stored Credentials
      ↓
   ┌──┴──┐
   ↓     ↓
 Match  No Match
   ↓     ↓
Success  Error

When the credentials match a registered account, the program displays:

Login successful!
Welcome, username!

Otherwise, the user receives an invalid credentials message and can try again.

❌ Error Handling

The program handles several invalid situations, including:

Empty or invalid usernames
Unsupported username characters
Duplicate usernames
Passwords shorter than 6 characters
Invalid menu selections
Non-numeric menu input
Missing users.txt
File opening errors during registration

Error messages are displayed using a different console color and an error sound.

📁 Project Structure

CodeAlpha_LoginAndRegistrationSystem/
│── 1. Screenshot.jpg
│── 2. Screenshot.jpg
│── 3. Screenshot.jpg
├── 4. Screenshot.jpg
├── README.md
└── main.cpp

users.txt is created/updated by the program when users register. It contains the locally stored credentials used by the application.

⚙️ Requirements

To compile and run this project:

Windows operating system
C++ compiler
C++ compatible IDE
Support for Windows API

The project uses:

#include <windows.h>

for console colors, delays, and sound effects.

▶️ How to Run

1. Clone the Repository

git clone https://github.com/MairaAdil/CodeAlpha_LoginAndRegistrationSystem.git

2. Open the Project

Open main.cpp in a C++ compatible IDE such as Visual Studio, Code::Blocks, or another Windows-based C++ development environment.

3. Compile the Program

Build/compile the C++ source file.

4. Run

Start the program and choose:

1 → Register
2 → Login
3 → Exit

🧪 Example Usage

Registration

========================================
             REGISTRATION
========================================

Enter username: Maira_123
Enter password: password123

Registration successful!

Login

========================================
                 LOGIN
========================================

Enter username: Maira_123
Enter password: password123

Login successful!
Welcome, Maira_123!

Invalid Login

Invalid username or password!
Please try again.

🎯 Learning Objectives

This project provided practical experience with:

Building a menu-driven C++ application
Implementing registration logic
Implementing login verification
Working with text files
Reading and writing file data
Validating user input
Detecting duplicate usernames
Creating reusable functions
Using Boolean validation functions
Working with Windows console features
Designing a basic authentication workflow

🚀 Future Improvements

The system could be further enhanced by adding:

Password hashing
Salted password storage
Password masking during input
Stronger password requirements
Password recovery
Account deletion
Username/password update
Login attempt limits
User-specific files or a database
Encrypted credential storage
Session management
Multi-user roles and permissions
More secure authentication mechanisms

⚠️ Project Scope

This application was created as an educational C++ project for the CodeAlpha Internship.

It demonstrates the fundamental workflow of registration and login using local file storage. It is not intended to replace a production authentication system.

👩‍💻 Author

Maira Adil

BS Artificial Intelligence Student University of Central Punjab

Connect With Me

LinkedIn: linkedin.com/in/mairaadil
GitHub: github.com/MairaAdil

🏆 CodeAlpha Internship

This project was completed as Task 2 — Login and Registration System during the CodeAlpha C++ Programming Internship.

The project helped strengthen practical understanding of C++ functions, file handling, validation, and basic authentication workflows.

🎇 Acknowledgment

Special thanks to CodeAlpha for providing the internship opportunity and project-based learning experience to practice and apply C++ programming concepts.

⭐ If you found this project useful, feel free to explore the repository and leave a star.

Name		Name	Last commit message	Last commit date
1. Screenshot.jpg		1. Screenshot.jpg
2. Screenshot.jpg		2. Screenshot.jpg
3. Screenshot.jpg		3. Screenshot.jpg
4. Screenshot.jpg		4. Screenshot.jpg
README.md		README.md
main.cpp		main.cpp

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