File system notifications for Go

Build Status


Cross platform, works on:

  • Windows
  • Linux
  • BSD
  • OSX


package main

import (


func main() {
	watcher, err := fsnotify.NewWatcher()
	if err != nil {

	done := make(chan bool)

	// Process events
	go func() {
		for {
			select {
			case ev := <-watcher.Event:
				log.Println("event:", ev)
			case err := <-watcher.Error:
				log.Println("error:", err)

	err = watcher.Watch("testDir")
	if err != nil {


	/* ... do stuff ... */

For each event:

  • Name
  • IsCreate()
  • IsDelete()
  • IsModify()
  • IsRename()


  • When a file is renamed to another directory is it still being watched?
    • No (it shouldn't be, unless you are watching where it was moved to).
  • When I watch a directory, are all subdirectories watched as well?
    • No, you must add watches for any directory you want to watch.
  • Do I have to watch the Error and Event channels in a separate goroutine?
    • As of now, yes. Looking into making this single-thread friendly.
  • There are OS-specific limits as to how many watches can be created:
    • Linux: /proc/sys/fs/inotify/max_user_watches contains the limit, reaching this limit results in a “no space left on device” error.
    • BSD / OSX: sysctl variables “kern.maxfiles” and “kern.maxfilesperproc”, reaching these limits results in a “too many open files” error.