Computer Network Final Project

This is a simple server-client implementation using TCP. The project includes functionality for sending messages, files, and even some fun options! Note that only one client is allowed to connect to the server at a time.

Table of Contents

• Environment
• Dependencies
• Features
• Usage
• Options

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Environment

This project is designed to run on macOS Sonoma 14.6.1. Compatibility with other macOS versions or operating systems is not guaranteed.

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Dependencies

This project requires the following external libraries:

1. OpenSSL

   • Used for secure connections between the server and client.
   • Installation:

     brew install openssl

   • Ensure OpenSSL is linked correctly:

     export LDFLAGS="-L/opt/homebrew/opt/openssl@3/lib"
     export CPPFLAGS="-I/opt/homebrew/opt/openssl@3/include"

2. PortAudio

   • Used for audio processing and playback.
   • Installation:

     brew install portaudio

3. mpg123

   • Used for decoding MP3 files for audio playback.
   • Installation:

     brew install mpg123

4. Standard C Libraries

   • Used for basic input/output and networking (<stdio.h>, <stdlib.h>, <string.h>, <arpa/inet.h>, <unistd.h>).

Ensure these libraries are properly installed before running the project.

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Features

This implementation includes the following features:

• Sending and receiving messages between the client and server.
• Sending messages to other clients.
• Registering and logging in users.
• Sending files to other clients.
• Receiving files from other clients.
• Fun and interactive options, including audio playback with PortAudio and mpg123.
• Encrypted message transfer.
• Beautiful and colorful client terminal interface.

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Usage

Follow these steps to compile and run the server and client:

1. Compile the Server and Client Use the provided Makefile to compile both the server and client programs:

   make

2. Start the Server

   ./server [port_number]

3. Start the Client We support up to 10 clients for a single server.

   ./client [port_number]

4. Example

   ./server 8080
   ./client 8080

If the makefile can't run properly on your machine, you can directly use the executable file "server" and "client" in the code directory to run the program.

Options

Log in ([L]):

• Enter your username and password to log in.
• If the credentials are correct, you will gain access to the system's features.
• If the credentials are incorrect, the server will notify you.

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Register ([R]):

• Create a new account by providing a unique username and password.
• The server will confirm successful registration.
• If the username is already in use, you will be asked to try another one.

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Quit ([Q]):

• Exit the application gracefully.

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Send a Message to the Server ([S]):

• Type a message, and it will be sent directly to the server.
• The server will respond with a confirmation message.

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Send a Message to Another User ([T]):

• Enter the recipient's username and the message you wish to send.
• If the user is valid, the message will be delivered.

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Read Messages from Others ([R]):

• View messages that have been sent to you by other users.
• The server will list the messages with the sender's username.

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Send a File to Another Client ([F]):

• Provide the filename and the recipient's username.
• The file will be securely transferred to the specified user.

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Get a File from Other Clients ([G]):

• View and download files that other users have sent to you.
• The file will be saved in your local directory.

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Listen to Chipi Chipi Chapa Chapa ([A]):

• Relax and enjoy a fun audio feature as a small Easter egg. 🐻🎶

Quit ([Q]):

• Exit the application gracefully.