TCP Chat

A command-line TCP chat server application that allows up to 10 clients to connect and communicate in a shared chat room.

Features

• Multi-client support
• Real-time chat functionality
• Color-coded usernames with unique color selection
• Chat history tracking
• Idle timeout management
• Logging system
• Clean client disconnection handling
• Private messaging support
• Command-based interaction
• IP-based connection restriction (one connection per IP)

Getting Started

Prerequisites

For running the application:

• No special prerequisites needed - the executable for linux is provided

For building from source:

• Go (Golang) installed on your system

Running the Server

You can run the server in several ways:

1. Using the provided executable without specifying a port (default port will be used):

./TCPChat

2. Using the provided executable with a specific port number:

./TCPChat [port]

3. Running from source code (requires Go installation):

go run .

or with a specific port:

go run . [port]

Connecting to the Server

You can connect to the server using the nc (netcat) command:

nc <host ip> [port]

Note: Only one connection per IP address is allowed. Multiple connections from the same IP will be rejected.

Usage

1. When you connect to the server, you will be prompted to enter your username
2. After username selection, you'll be asked to choose a unique color for your messages (each user must have a different color)
3. After successful login, you can start chatting with other connected users
4. Messages are broadcast to all connected clients
5. The server maintains a chat history
6. Inactive users will be automatically disconnected after a period of inactivity

Available Commands

The chat supports several commands for enhanced interaction:

• -h or --help: Display help message with all available commands
• -r [new_name] or --rename [new_name]: Change your username
• -c or --color: Change your display color
• -dm [username] [message]: Send a private message to a specific user
• -u or --users: List all online users
• -q or --quit: Leave the chat

Color System

• Each user must select a unique color upon joining
• Colors are used to distinguish between different users in the chat
• If a desired color is already taken, you'll need to choose a different one
• You can change your color later using the -c command
• Available colors will be displayed during selection

Implementation Details

The application is built with the following components:

• Main server handler
• Client connection management
• Chat display and formatting
• User authentication
• Message history tracking
• Idle timeout checker
• Logging system
• Color management system
• Command processor

Error Handling

The application includes robust error handling for:

• Invalid port numbers
• Connection issues
• Client disconnections
• Invalid usernames
• Duplicate colors
• Invalid commands
• Network errors
• Multiple connection attempts from same IP
• Connection limit enforcement

Authors

• Irem (@iremnurc)
• Taha (@tcavuslu)
• Thanos