Minitalk

a simple project that demonstrates inter-process communication using Unix signals. It involves creating a server and a client, where the client sends messages to the server using signals, and the server decodes and handles those messages.

Features

• Server-Client Communication using signals
• Message Encoding and Decoding: Messages are transmitted bit by bit using the SIGUSR1 and SIGUSR2 signals.
• Signal-based Communication instead of traditional sockets or IPC mechanisms.
• Lightweight and efficient: Demonstrates an interesting way to exchange information without relying on external libraries.

How It Works

1. Client: Sends a message to the server by using a series of signals (SIGUSR1 for 0 and SIGUSR2 for 1).
2. Server: Listens for incoming signals and reconstructs the message from the signals received.
3. Communication Flow:
   • The server needs to be running first.
   • The client sends a string (message) encoded in binary using signals.
   • The server receives the signals, decodes the message, and prints it on the console.

Project Structure

minitalk/
├── src/                   # Main source directory
│   ├── src_client/         # Client source code
│   │   ├── cli_utiles.c    # Client utility functions
│   │   ├── client.h        # Client header file
│   │   ├── main.c          # Client program entry point
│   ├── src_server/         # Server source code
│   │   ├── ft_putnbr.c     # Helper function to print numbers
│   │   ├── main.c          # Server program entry point
│   │   ├── server.h        # Server header file
│   │   ├── srv_utiles.c    # Server utility functions
│   ├── Makefile            # Makefile to build the project
├── src_client_bonus/       # Bonus client source code
│   ├── cli_helper_bonus.c  # Bonus client helper functions
│   ├── cli_utiles_bonus.c  # Bonus client utility functions
│   ├── client_bonus.h      # Bonus client header file
│   ├── main_bonus.c        # Bonus client main entry point
├── src_server_bonus/       # Bonus server source code
│   ├── buffer_bonus.c      # Bonus buffer handling
│   ├── ft_putnbr_bonus.c   # Bonus number printing helper
│   ├── main_bonus.c        # Bonus server entry point
│   ├── server_bonus.h      # Bonus server header
│   ├── server_helper_bonus.c  # Bonus server helper functions
│   ├── srv_utiles_bonus.c  # Bonus server utility functions
└── README.md               # Project documentation

Compilation

1. Clone the repository:

   git clone https://github.com/iaceene/minitalk42.git
   cd minitalk42

2. Use the Makefile to compile both the server and client:

   make

3. This will create the following executables:

   • server: The program that will listen for incoming signals.
   • client: The program that will send signals to the server.

Usage

1. Start the server: Open a terminal and run the server program:

   ./server

2. Start the client: In another terminal, run the client program with the PID of the running server and the message you want to send:

   ./client <server_pid> "Hello, Minitalk!"

   Example:

   ./client 12345 "Hello"

   • The client will send the message "Hello" to the server, and the server will print it as it is decoded.

Example

Running the Server:

$ ./server
PID : 1234

Running the Client:

$ ./client <server_pid> "Hello World"

The server will output:

>> Hello World

Signal Handling

• The communication uses the SIGUSR1 and SIGUSR2 signals for encoding the message:
  • SIGUSR1: Represents a binary 1
  • SIGUSR2: Represents a binary 0

The message is sent bit by bit, with each signal representing a single bit of the message.

Notes

• Signal Safety: Signals are a low-level form of inter-process communication. Ensure that your signal handler functions are minimal and do not rely on non-async-safe functions.
• Error Handling: The program assumes basic error handling, such as invalid PID or failure to send/receive signals.
• OS Compatibility: This project assumes you're working on a Unix-like operating system (Linux, macOS)..

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If you have any questions or issues, feel free to open an issue or reach out!