What is the Windows equivalent of process.on('SIGINT') in node.js?

Question

I\'m following the guidance here (listening for SIGINT events) to gracefully shutdown my Windows-8-hosted node.js application in response to Ctrl+

Answer 1

I'm not sure as of when, but on node 8.x and on Windows 10 the original question code simply works now.

process.on( "SIGINT", function() {
  console.log( "\ngracefully shutting down from SIGINT (Crtl-C)" );
  process.exit();
} );

process.on( "exit", function() {
  console.log( "never see this log message" );
} );

setInterval( () => console.log( "tick" ), 2500 );

also works with a windows command prompt.

Answer 2

Since node.js 0.8 the keypress event no longer exists. There is however an npm package called keypress that reimplements the event.

Install with npm install keypress, then do something like:

// Windows doesn't use POSIX signals
if (process.platform === "win32") {
    const keypress = require("keypress");
    keypress(process.stdin);
    process.stdin.resume();
    process.stdin.setRawMode(true);
    process.stdin.setEncoding("utf8");
    process.stdin.on("keypress", function(char, key) {
        if (key && key.ctrl && key.name == "c") {
            // Behave like a SIGUSR2
            process.emit("SIGUSR2");
        } else if (key && key.ctrl && key.name == "r") {
            // Behave like a SIGHUP
            process.emit("SIGHUP");
        }
    });
}

Answer 3

Currently there is still no support in node for capturing the windows console control events, so there are no equivalents to the POSIX signals:

https://github.com/joyent/node/issues/1553

However the tty module documentation does give an example of a mechanism to capture the key presses in order to initiate a graceful shutdown, but then this does only work for ctrl+c.

var tty = require('tty');

process.stdin.resume();
tty.setRawMode(true);

process.stdin.on('keypress', function(char, key) {
  if (key && key.ctrl && key.name == 'c') {
    console.log('graceful exit of process %d', process.pid);
    process.exit();
  }
});

Answer 4

Nowadays it just works on all platforms, including Windows.

The following code logs and then terminates properly on Windows 10:

process.on('SIGINT', () => {
    console.log("Terminating...");
    process.exit(0);
});

Answer 5

Unless you need the "readline" import for other tasks, I would suggest importing "readline" once the program has verified that it's running on Windows. Additionally, for those who might be unaware - this works on both Windows 32-bit and Windows 64-bit systems (which will return the keyword "win32"). Thanks for this solution Gabriel.

if (process.platform === "win32") {
  require("readline")
    .createInterface({
      input: process.stdin,
      output: process.stdout
    })
    .on("SIGINT", function () {
      process.emit("SIGINT");
    });
}

process.on("SIGINT", function () {
  // graceful shutdown
  process.exit();
});

Answer 6

You have to use the readline module and listen for a SIGINT event:

http://nodejs.org/api/readline.html#readline_event_sigint

if (process.platform === "win32") {
  var rl = require("readline").createInterface({
    input: process.stdin,
    output: process.stdout
  });

  rl.on("SIGINT", function () {
    process.emit("SIGINT");
  });
}

process.on("SIGINT", function () {
  //graceful shutdown
  process.exit();
});