94 lines
2.3 KiB
Markdown
94 lines
2.3 KiB
Markdown
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# File system notifications for Go
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[](http://godoc.org/github.com/howeyc/fsnotify)
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Cross platform: Windows, Linux, BSD and OS X.
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## Moving Notice
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There is a fork being actively developed with a new API in preparation for the Go Standard Library:
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[github.com/go-fsnotify/fsnotify](https://github.com/go-fsnotify/fsnotify)
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## Example:
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```go
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package main
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import (
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"log"
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"github.com/howeyc/fsnotify"
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)
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func main() {
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watcher, err := fsnotify.NewWatcher()
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if err != nil {
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log.Fatal(err)
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}
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done := make(chan bool)
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// Process events
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go func() {
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for {
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select {
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case ev := <-watcher.Event:
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log.Println("event:", ev)
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case err := <-watcher.Error:
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log.Println("error:", err)
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}
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}
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}()
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err = watcher.Watch("testDir")
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if err != nil {
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log.Fatal(err)
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}
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// Hang so program doesn't exit
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<-done
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/* ... do stuff ... */
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watcher.Close()
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}
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```
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For each event:
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* Name
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* IsCreate()
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* IsDelete()
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* IsModify()
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* IsRename()
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## FAQ
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**When a file is moved to another directory is it still being watched?**
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No (it shouldn't be, unless you are watching where it was moved to).
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**When I watch a directory, are all subdirectories watched as well?**
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No, you must add watches for any directory you want to watch (a recursive watcher is in the works [#56][]).
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**Do I have to watch the Error and Event channels in a separate goroutine?**
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As of now, yes. Looking into making this single-thread friendly (see [#7][])
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**Why am I receiving multiple events for the same file on OS X?**
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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][]).
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**How many files can be watched at once?**
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There are OS-specific limits as to how many watches can be created:
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* Linux: /proc/sys/fs/inotify/max_user_watches contains the limit,
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reaching this limit results in a "no space left on device" error.
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* BSD / OSX: sysctl variables "kern.maxfiles" and "kern.maxfilesperproc", reaching these limits results in a "too many open files" error.
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[#62]: https://github.com/howeyc/fsnotify/issues/62
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[#56]: https://github.com/howeyc/fsnotify/issues/56
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[#54]: https://github.com/howeyc/fsnotify/issues/54
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[#7]: https://github.com/howeyc/fsnotify/issues/7
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