io.js有一个exit和一个beforeExit事件，它们做你想做的事情。

我需要在退出时做一个异步清理操作，这个问题的答案都不适合我。

所以我自己试了一下，最后发现了这个:

process.once('uncaughtException', async () => {
  await cleanup()

  process.exit(0)
})

process.once('SIGINT', () => { throw new Error() })

这将捕获我能找到的可以处理的每个退出事件。目前看来很可靠，也很干净。

[`exit`, `SIGINT`, `SIGUSR1`, `SIGUSR2`, `uncaughtException`, `SIGTERM`].forEach((eventType) => {
  process.on(eventType, cleanUpServer.bind(null, eventType));
})

io.js有一个exit和一个beforeExit事件，它们做你想做的事情。

这里有一个针对windows的好方法

process.on('exit', async () => {
    require('fs').writeFileSync('./tmp.js', 'crash', 'utf-8')
});

function fnAsyncTest(callback) {
    require('fs').writeFile('async.txt', 'bye!', callback);
}

function fnSyncTest() {
    for (var i = 0; i < 10; i++) {}
}

function killProcess() {

    if (process.exitTimeoutId) {
        return;
    }

    process.exitTimeoutId = setTimeout(() => process.exit, 5000);
    console.log('process will exit in 5 seconds');

    fnAsyncTest(function() {
        console.log('async op. done', arguments);
    });

    if (!fnSyncTest()) {
        console.log('sync op. done');
    }
}

// https://nodejs.org/api/process.html#process_signal_events
process.on('SIGTERM', killProcess);
process.on('SIGINT', killProcess);

process.on('uncaughtException', function(e) {

    console.log('[uncaughtException] app will be terminated: ', e.stack);

    killProcess();
    /**
     * @https://nodejs.org/api/process.html#process_event_uncaughtexception
     *  
     * 'uncaughtException' should be used to perform synchronous cleanup before shutting down the process. 
     * It is not safe to resume normal operation after 'uncaughtException'. 
     * If you do use it, restart your application after every unhandled exception!
     * 
     * You have been warned.
     */
});

console.log('App is running...');
console.log('Try to press CTRL+C or SIGNAL the process with PID: ', process.pid);

process.stdin.resume();
// just for testing