How to Write Signal Handlers in Rust

Rust does not support traditional OS signal handlers because its memory safety guarantees conflict with the asynchronous nature of signals. You must use external crates like signal-hook to register callbacks that safely handle signals without violating the borrow checker.

use signal_hook::consts::signal::SIGINT;
use signal_hook::iterator::Signals;

fn main() {
    let mut signals = Signals::new(&[SIGINT]).unwrap();
    for _signal in signals.forever() {
        println!("Received SIGINT, exiting gracefully.");
        break;
    }
}

Add signal-hook = "0.3" to your Cargo.toml dependencies.

Rust prevents you from writing code that runs instantly when an OS signal arrives because it could crash your program by accessing memory incorrectly. Instead, you use a helper tool that listens for these signals and tells your main program to handle them safely at the next available moment. Think of it like a secretary who takes a message for you and hands it to you only when you are free to read it.