Multi-Client Chat Application

This project is a multi-client chat application implemented in C using TCP sockets and POSIX threads. It consists of a server that handles multiple clients and a client program that connects to the server.

Features

• Multiple clients can connect to the server simultaneously.
• Clients can send messages to all other connected clients.
• Private messaging with the /w <username> <message> command.
• Clients can disconnect using /quit.
• The server can shut down all connections using /shutdown.

Files

• task3_client.c: Client implementation for Task 3.
• task3_server.c: Server implementation for Task 3.
• Makefile: Compilation instructions.

Compilation

To compile the project, use:

make

To clean the compiled binaries:

make clean

Usage

Start the Server

./task3_server <port>

Start a Client

./task3_client <username> <port>

Commands

• /quit – Disconnects the client.
• /shutdown – Shuts down the server and disconnects all clients.
• /w <username> <message> – Sends a private message to a specific user.

Implementation Details

Server

• Listens for incoming connections and spawns a new thread for each client.
• Maintains a list of connected clients.
• Broadcasts messages to all clients except the sender.
• Supports private messaging.
• Handles client disconnections and removes them from the active client list.

Client

• Connects to the server and sends the username upon connection.
• Runs a separate thread to listen for messages from the server.
• Reads user input and sends messages to the server.
• Supports private messaging and disconnection commands.

Dependencies

• POSIX Threads (-pthread)
• Real-Time Library (-lrt)

Notes

• The server runs indefinitely until manually stopped or a client sends /shutdown.
• The maximum number of clients is defined as MAX_CLIENTS in the server code.
• The message buffer size is defined as MAX_SIG.