Handle OS signals

⚠️ Windows supports listening for SIGINT, SIGBREAK, SIGTERM, SIGQUIT, SIGHUP, and SIGWINCH (all except SIGINT/SIGBREAK go through libuv’s Windows signal emulation).

Concepts

• Ende.addSignalListener() can be used to capture and monitor OS signals.
• Ende.removeSignalListener() can be used to stop watching the signal.

Set up an OS signal listener

APIs for handling OS signals are modelled after already familiar addEventListener and removeEventListener APIs.

⚠️ Note that listening for OS signals doesn’t prevent event loop from finishing, ie. if there are no more pending async operations the process will exit.

You can use Ende.addSignalListener() function for handling OS signals:

console.log("Press Ctrl-C to trigger a SIGINT signal");

Ende.addSignalListener("SIGINT", () => {
  console.log("interrupted!");
  Ende.exit();
});

// Add a timeout to prevent process exiting immediately.
setTimeout(() => {}, 5000);

Run with:

ende run add_signal_listener.ts

You can use Ende.removeSignalListener() function to unregister previously added signal handler.

console.log("Press Ctrl-C to trigger a SIGINT signal");

const sigIntHandler = () => {
  console.log("interrupted!");
  Ende.exit();
};
Ende.addSignalListener("SIGINT", sigIntHandler);

// Add a timeout to prevent process exiting immediately.
setTimeout(() => {}, 5000);

// Stop listening for a signal after 1s.
setTimeout(() => {
  Ende.removeSignalListener("SIGINT", sigIntHandler);
}, 1000);

Run with:

ende run signal_listeners.ts

Windows support

The supported signal set differs between platforms. The Windows-specific behavior is:

SIGKILL and SIGABRT are deliberately not registerable via addSignalListener — they’re uncatchable / fatal, matching Unix semantics. On Windows the catchable signals all forward to libuv’s emulation layer; signals sent via Ende.kill ultimately invoke TerminateProcess.