system-programming/exercises/signal_handler/README.md

Signal Handler

Overview

This project demonstrates how to handle UNIX signals in C using sigaction.
It specifically intercepts SIGINT and SIGUSR1 and prints messages when these signals are received.

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Features

• Intercepts SIGINT (usually generated with Ctrl + C) and SIGUSR1`.
• Prints a custom message for each signal.
• Tracks the number of SIGINT signals received and terminates after a defined count.
• Demonstrates proper use of:
  • sigaction() instead of signal() for consistent behavior.
  • volatile sig_atomic_t for safe signal state handling.

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Build

make

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Run

./signal_handler

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Test

• Open another terminal and run:

kill -USR1 <PID>

where <PID> is the process ID of signal_handler.

• Press Ctrl + C in the terminal running the program to send SIGINT.

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Clean

make clean