C++ Socket-Based Chat System

A multi-threaded, client-server chat system built from scratch in C++ using TCP/IP sockets. It's designed to handle multiple concurrent users for real-time messaging, showcasing fundamental low-level network programming and concurrency concepts.

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Features

• Multi-Threaded Server: Utilizes a thread-per-client model to handle multiple concurrent users in parallel.
• Real-time Messaging: Supports both public broadcast messages and private one-to-one messages.
• User Nicknames: Allows users to set and change their nicknames with the /nick command.
• Online User List: Users can request a list of all currently connected clients with the /list command.
• Graceful Shutdown: The server can be shut down cleanly using a SHUTDOWN command in its console, notifying all clients.
• External Configuration: The server port is configured via an external server.conf file, so no recompilation is needed to change it.
• Asynchronous Client: The client uses select() to handle both user input and network messages simultaneously, ensuring notifications are never missed.
• Object-Oriented Design: The server code is refactored into a clean, encapsulated Server class.

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Building the Project

Prerequisites

• A C++ compiler that supports C++17 (e.g., g++ or clang++)
• make

Instructions

1. Clone the repository:

   git clone https://github.com/Angad8285/cpp-chat-system

2. Navigate to the project directory:

   cd cpp-chat-system

3. Compile the project:

   make

   This will create two executables in your root directory: server and client.

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Running the Application

You will need at least two separate terminal windows.

1. Start the Server: In your first terminal, run the server executable:

   ./server

   The server will start and listen on the port specified in server.conf (default is 8080).

2. Start the Client(s): In one or more other terminals, run the client executable:

   ./client

   The client will connect to the server. You can now start chatting!

3. Server Administration:

   • To change the port, edit the PORT value in the server.conf file and restart the server.
   • To shut down the server gracefully, type SHUTDOWN in the server's terminal window and press Enter.

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Chat Usage

Once connected, you can type messages to send them publicly. The following special commands are available:

• /nick <new_name> - Changes your nickname.
  • Example: /nick Alice
• /msg <username> <message> - Sends a private message to a specific user.
  • Example: /msg Bob Hello there!
• /list - Shows a list of all users currently online.
• /exit - Disconnects you from the server.