README

Node.js - death

Gracefully cleanup when termination signals are sent to your process.

Why?

Because adding clean up callbacks for uncaughtException, SIGINT, and SIGTERM is annoying. Ideally, you can use this package to put your cleanup code in one place and exit gracefully if you need to.

Operating System Compatibility

It's only been tested on POSIX compatible systems. Here's a nice discussion on Windows signals, apparently, this has been fixed/mapped.

Installation

npm install death

Example

var ON_DEATH = require('death'); //this is intentionally ugly

ON_DEATH(function(signal, err) {
  //clean up code here
})

Usage

By default, it sets the callback on SIGINT, SIGQUIT, and SIGTERM.

Signals

SIGINT: Sent from CTRL-C
SIGQUIT: Sent from keyboard quit action.
SIGTERM: Sent from operating system kill.

More discussion and detail: http://www.gnu.org/software/libc/manual/html_node/Termination-Signals.html and http://pubs.opengroup.org/onlinepubs/009695399/basedefs/signal.h.html and http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap11.html.

AS they pertain to Node.js: http://dailyjs.com/2012/03/15/unix-node-signals/

Want to catch uncaughtException?

No problem, do this:

var ON_DEATH = require('death')({uncaughtException: true})

Want to know which signals are being caught?

Do this:

var ON_DEATH = require('death')({debug: true})

Your process will then log anytime it catches these signals.

Want to catch SIGHUP?

Be careful with this one though. Typically this is fired if your SSH connection dies, but can also be fired if the program is made a daemon.

Do this:

var ON_DEATH = require('death')({SIGHUP: true})

Why choose the ugly "ON_DEATH"?

Name it whatever you want. I like ON_DEATH because it stands out like a sore thumb in my code.

Want to remove event handlers?

If you want to remove event handlers ON_DEATH returns a function for cleaning up after itself:

var ON_DEATH = require('death')
var OFF_DEATH = ON_DEATH(function(signal, err) {
  //clean up code here
})

// later on...
OFF_DEATH();

License

(MIT License)

Usage no npm install needed!