README

File system notifications for Go

GoDoc

This branch contains fsnotify.v0 which is API-compatible with howeyc/fsnotify. Bugfixes may be backported, but I recommend upgrading.

Cross platform: Windows, Linux, BSD and OS X.

Example:

package main

import (
	"log"

	"gopkg.in/fsnotify.v0"
)

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

	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 {
		log.Fatal(err)
	}

	<-done

	/* ... do stuff ... */
	watcher.Close()
}

For each event:

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

FAQ

When a file is moved 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 (a recursive watcher is in the works #56).

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 (see #7)

Why am I receiving multiple events for the same file on OS X?

Spotlight indexing on OS X can result in multiple events (see #62). A temporary workaround is to add your folder(s) to the Spotlight Privacy settings until we have a native FSEvents implementation (see #54).

How many files can be watched at once?

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.

Documentation

Overview

Package fsnotify provides a platform-independent interface for file system notifications.

Index

Examples

Constants

View Source
const (
	FSN_CREATE = 1
	FSN_MODIFY = 2
	FSN_DELETE = 4
	FSN_RENAME = 8

	FSN_ALL = FSN_MODIFY | FSN_DELETE | FSN_RENAME | FSN_CREATE
)

Variables

This section is empty.

Functions

This section is empty.

Types

type FileEvent

type FileEvent struct {
	Name string // File name (optional)
	// contains filtered or unexported fields
}

func (*FileEvent) IsAttrib

func (e *FileEvent) IsAttrib() bool

IsAttrib reports whether the FileEvent was triggered by a change in the file metadata.

func (*FileEvent) IsCreate

func (e *FileEvent) IsCreate() bool

IsCreate reports whether the FileEvent was triggered by a creation

func (*FileEvent) IsDelete

func (e *FileEvent) IsDelete() bool

IsDelete reports whether the FileEvent was triggered by a delete

func (*FileEvent) IsModify

func (e *FileEvent) IsModify() bool

IsModify reports whether the FileEvent was triggered by a file modification or attribute change

func (*FileEvent) IsRename

func (e *FileEvent) IsRename() bool

IsRename reports whether the FileEvent was triggered by a change name

func (*FileEvent) String

func (e *FileEvent) String() string

String formats the event e in the form "filename: DELETE|MODIFY|..."

type Watcher

type Watcher struct {
	Error chan error // Errors are sent on this channel

	Event chan *FileEvent // Events are returned on this channel
	// contains filtered or unexported fields
}

func NewWatcher

func NewWatcher() (*Watcher, error)

NewWatcher creates and returns a new inotify instance using inotify_init(2)

Example
package main

import (
	"log"

	"github.com/go-fsnotify/fsnotify"
)

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

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

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

func (*Watcher) Close

func (w *Watcher) Close() error

Close closes an inotify watcher instance It sends a message to the reader goroutine to quit and removes all watches associated with the inotify instance

func (*Watcher) RemoveWatch

func (w *Watcher) RemoveWatch(path string) error

Remove a watch on a file

func (*Watcher) Watch

func (w *Watcher) Watch(path string) error

Watch a given file path

func (*Watcher) WatchFlags

func (w *Watcher) WatchFlags(path string, flags uint32) error

Watch a given file path for a particular set of notifications (FSN_MODIFY etc.)