index.js

var http = require('http');

console.log(process.pid);

http.createServer().listen(9001);

process.on('SIGINT', function () {
  console.log('I totally caught this and won\'t exit');
});

Info.md

• When this app is started with node index, a SIGINT (Ctrl+c) is caught by the app and it continues running.
• When this app is started with npm start, a SIGINT causes npm to exit, detaching the still running node process from the foreground.

package.json

{
  "name": "example",
  "scripts": {
    "start": "node index"
  }
}