131 lines
5.9 KiB
Markdown
Vendored
131 lines
5.9 KiB
Markdown
Vendored
# File system notifications for Go
|
|
|
|
[](https://godoc.org/github.com/fsnotify/fsnotify) [](https://goreportcard.com/report/github.com/fsnotify/fsnotify)
|
|
|
|
fsnotify utilizes [golang.org/x/sys](https://godoc.org/golang.org/x/sys) rather than `syscall` from the standard library. Ensure you have the latest version installed by running:
|
|
|
|
```console
|
|
go get -u golang.org/x/sys/...
|
|
```
|
|
|
|
Cross platform: Windows, Linux, BSD and macOS.
|
|
|
|
| Adapter | OS | Status |
|
|
| --------------------- | -------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
|
|
| inotify | Linux 2.6.27 or later, Android\* | Supported [](https://travis-ci.org/fsnotify/fsnotify) |
|
|
| kqueue | BSD, macOS, iOS\* | Supported [](https://travis-ci.org/fsnotify/fsnotify) |
|
|
| ReadDirectoryChangesW | Windows | Supported [](https://travis-ci.org/fsnotify/fsnotify) |
|
|
| FSEvents | macOS | [Planned](https://github.com/fsnotify/fsnotify/issues/11) |
|
|
| FEN | Solaris 11 | [In Progress](https://github.com/fsnotify/fsnotify/issues/12) |
|
|
| fanotify | Linux 2.6.37+ | [Planned](https://github.com/fsnotify/fsnotify/issues/114) |
|
|
| USN Journals | Windows | [Maybe](https://github.com/fsnotify/fsnotify/issues/53) |
|
|
| Polling | *All* | [Maybe](https://github.com/fsnotify/fsnotify/issues/9) |
|
|
|
|
\* Android and iOS are untested.
|
|
|
|
Please see [the documentation](https://godoc.org/github.com/fsnotify/fsnotify) and consult the [FAQ](#faq) for usage information.
|
|
|
|
## API stability
|
|
|
|
fsnotify is a fork of [howeyc/fsnotify](https://godoc.org/github.com/howeyc/fsnotify) with a new API as of v1.0. The API is based on [this design document](http://goo.gl/MrYxyA).
|
|
|
|
All [releases](https://github.com/fsnotify/fsnotify/releases) are tagged based on [Semantic Versioning](http://semver.org/). Further API changes are [planned](https://github.com/fsnotify/fsnotify/milestones), and will be tagged with a new major revision number.
|
|
|
|
Go 1.6 supports dependencies located in the `vendor/` folder. Unless you are creating a library, it is recommended that you copy fsnotify into `vendor/github.com/fsnotify/fsnotify` within your project, and likewise for `golang.org/x/sys`.
|
|
|
|
## Usage
|
|
|
|
```go
|
|
package main
|
|
|
|
import (
|
|
"log"
|
|
|
|
"github.com/fsnotify/fsnotify"
|
|
)
|
|
|
|
func main() {
|
|
watcher, err := fsnotify.NewWatcher()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
defer watcher.Close()
|
|
|
|
done := make(chan bool)
|
|
go func() {
|
|
for {
|
|
select {
|
|
case event, ok := <-watcher.Events:
|
|
if !ok {
|
|
return
|
|
}
|
|
log.Println("event:", event)
|
|
if event.Op&fsnotify.Write == fsnotify.Write {
|
|
log.Println("modified file:", event.Name)
|
|
}
|
|
case err, ok := <-watcher.Errors:
|
|
if !ok {
|
|
return
|
|
}
|
|
log.Println("error:", err)
|
|
}
|
|
}
|
|
}()
|
|
|
|
err = watcher.Add("/tmp/foo")
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
<-done
|
|
}
|
|
```
|
|
|
|
## Contributing
|
|
|
|
Please refer to [CONTRIBUTING][] before opening an issue or pull request.
|
|
|
|
## Example
|
|
|
|
See [example_test.go](https://github.com/fsnotify/fsnotify/blob/master/example_test.go).
|
|
|
|
## 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 on the roadmap [#18][]).
|
|
|
|
**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 [howeyc #7][#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 [howeyc #62][#62]). A temporary workaround is to add your folder(s) to the *Spotlight Privacy settings* until we have a native FSEvents implementation (see [#11][]).
|
|
|
|
**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.
|
|
|
|
**Why don't notifications work with NFS filesystems or filesystem in userspace (FUSE)?**
|
|
|
|
fsnotify requires support from underlying OS to work. The current NFS protocol does not provide network level support for file notifications.
|
|
|
|
[#62]: https://github.com/howeyc/fsnotify/issues/62
|
|
[#18]: https://github.com/fsnotify/fsnotify/issues/18
|
|
[#11]: https://github.com/fsnotify/fsnotify/issues/11
|
|
[#7]: https://github.com/howeyc/fsnotify/issues/7
|
|
|
|
[contributing]: https://github.com/fsnotify/fsnotify/blob/master/CONTRIBUTING.md
|
|
|
|
## Related Projects
|
|
|
|
* [notify](https://github.com/rjeczalik/notify)
|
|
* [fsevents](https://github.com/fsnotify/fsevents)
|
|
|