fs.watch()

fs.watch(filename[, options][, listener])

Watch for changes on filename, where filename is either a file or a directory. The returned object is a fs.FSWatcher.

The second argument is optional. The options if provided should be an object. The supported boolean members are persistent and recursive. persistent indicates whether the process should continue to run as long as files are being watched. recursive indicates whether all subdirectories should be watched, or only the current directory. This applies when a directory is specified, and only on supported platforms (See Caveats).

The default is { persistent: true, recursive: false }.

The listener callback gets two arguments (event, filename). event is either 'rename' or 'change', and filename is the name of the file which triggered the event.