gracefully closing node.js applications via signal handling

To make your node.js application gracefully respond to shutdown signals, use process.on(SIGNAL,HANDLER).

For example, to respond to SIGINT (typically Ctrl-c), you can use:

process.on( "SIGINT", function() {
  console.log('CLOSING [SIGINT]');
  process.exit();
} );

Note that without the process.exit(), the program will not be shutdown. (This is you chance to override or "trap" the signal.)

Some common examples (in CoffeeScript):

process.on 'SIGHUP',  ()->console.log('CLOSING [SIGHUP]');  process.exit()
process.on 'SIGINT',  ()->console.log('CLOSING [SIGINT]');  process.exit()
process.on 'SIGQUIT', ()->console.log('CLOSING [SIGQUIT]'); process.exit()
process.on 'SIGABRT', ()->console.log('CLOSING [SIGABRT]'); process.exit()
process.on 'SIGTERM', ()->console.log('CLOSING [SIGTERM]'); process.exit()

PS: On Linux (and similar) you can enter kill -l on the command line to see a list of possible signals, and kill -N PID to send signal N to the process with process ID PID.