minitalk

📡 Description

minitalk is a 42 project that introduces inter-process communication in Unix using POSIX signals. The objective is to implement a basic client-server communication system, where messages are transmitted bit by bit using SIGUSR1 and SIGUSR2.

This project offers a hands-on approach to signal handling, bit manipulation, and asynchronous communication.

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🎯 Objective

Build two programs :

• Server : Waits for messages sent by clients.
• Client : Sends a message (string) to the server, one bit at a time, using Unix signals.

Once the server receives the full message, it prints it to the terminal.

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🚀 Features

✅ Communication System

• Sends messages from client to server using :
  • SIGUSR1 → bit 0.
  • SIGUSR2 → bit 1.
• Signals are sent for each bit of each character in the message.
• End of message is marked by a null terminator ('\0').

📥 Server

• Starts by displaying its PID.
• Listens for incoming bits and rebuilds characters.
• Prints the received message to the terminal.

📤 Client

• Takes the server PID and the message as arguments.
• Converts each character of the string into binary.
• Sends each bit with a corresponding signal.
• Waits briefly between signals to ensure the server processes them.

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🧠 Technical Highlights

• Uses sigaction() for signal handling.
• Implements signal acknowledgment (optional bonus).
• Handles message termination and edge cases.
• Ensures reliable bitwise transmission via proper timing.

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🛠️ Compilation

make
./server

In another terminal.

./client <PID> <Message>

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📝 Resources

• 1 : https://webusers.i3s.unice.fr/~tettaman/Classes/L2I/ProgSys/6_ProgSysLinuxSignaux.pdf