onDeath()

Syntax: onDeath(callbackFn, options);

The callbackFn will run just before the Node.js process exits.

The options

The options object is by default:

{
    SIGINT: true,
    SIGHUP: true,
    SIGQUIT: true,
    SIGTERM: true,
    uncaughtException: true,
    exit: true
}

You can override the defaults:

// Override uncaughtException:
onDeath(myCleanUpFn, { uncaughtException: false });

Abort program termination

The callbackFn can abort program termination by returning false, if the termination was triggered by SIGINT, SIGHUP, SIGQUIT, SIGTERM or an unhandled exception. In other cases, it is not possible to abort program termination.

Note! ALL your callbacks WILL run when the program is about to terminate. If your first callback returns false, the other callbacks will still run. Then, program termination is aborted after all callbacks has finished.

Regarding asynchronous clean up functions

If you have asynchronous clean up jobs, you could return false to abort program termination, and then do a process.exit() yourself when your asynch jobs are finished. However, as stated above, it is not always possible to abort program termination.