Slightly modified fsnotify-test.go. In theory this would add newly created directories to the active watcher. In practise, on OS X, it quickly runs out of file resources and crashes.

gistfile1.txt

package main

import (
  "github.com/howeyc/fsnotify"
	"log"
	"os"
)

func ExampleNewWatcher() {
	watcher, err := fsnotify.NewWatcher()
	if err != nil {
		log.Fatal(err)
	}

	go func() {
		for {
			select {
			case ev := <-watcher.Event:
				if ev.IsCreate() {
					fn := ev.Name
					fi, err := os.Lstat(fn)
					if err != nil {
						log.Fatal(err)
					}
					if fi.IsDir() {
						err = watcher.Watch(fn)
						if err != nil {
							log.Fatal(err)
						}
						log.Println(">>", fn)
					}
				}
				// log.Println("event:", ev)
			case err := <-watcher.Error:
				log.Println("error:", err)
			}
		}
	}()

	err = watcher.Watch("/tmp/foo")
	if err != nil {
		log.Fatal(err)
	}
}