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fsnotify example: Detect file changes in real time.
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package main | |
import ( | |
"log" | |
"os" | |
"time" | |
"github.com/fsnotify/fsnotify" | |
) | |
func waitUntilFind(filename string) error { | |
for { | |
time.Sleep(1 * time.Second) | |
_, err := os.Stat(filename) | |
if err != nil { | |
if os.IsNotExist(err) { | |
continue | |
} else { | |
return err | |
} | |
} | |
break | |
} | |
return nil | |
} | |
func main() { | |
if len(os.Args) != 2 { | |
log.Fatalln("error") | |
} | |
filename := os.Args[1] | |
err := waitUntilFind(filename) | |
if err != nil { | |
log.Fatalln(err) | |
} | |
watcher, err := fsnotify.NewWatcher() | |
if err != nil { | |
log.Fatalln(err) | |
} | |
defer watcher.Close() | |
err = watcher.Add(filename) | |
if err != nil { | |
log.Fatalln(err) | |
} | |
renameCh := make(chan bool) | |
removeCh := make(chan bool) | |
errCh := make(chan error) | |
go func() { | |
for { | |
select { | |
case event := <-watcher.Events: | |
switch { | |
case event.Op&fsnotify.Write == fsnotify.Write: | |
log.Printf("Write: %s: %s", event.Op, event.Name) | |
case event.Op&fsnotify.Create == fsnotify.Create: | |
log.Printf("Create: %s: %s", event.Op, event.Name) | |
case event.Op&fsnotify.Remove == fsnotify.Remove: | |
log.Printf("Remove: %s: %s", event.Op, event.Name) | |
removeCh <- true | |
case event.Op&fsnotify.Rename == fsnotify.Rename: | |
log.Printf("Rename: %s: %s", event.Op, event.Name) | |
renameCh <- true | |
case event.Op&fsnotify.Chmod == fsnotify.Chmod: | |
log.Printf("Chmod: %s: %s", event.Op, event.Name) | |
} | |
case err := <-watcher.Errors: | |
errCh <- err | |
} | |
} | |
}() | |
go func() { | |
for { | |
select { | |
case <-renameCh: | |
err = waitUntilFind(filename) | |
if err != nil { | |
log.Fatalln(err) | |
} | |
err = watcher.Add(filename) | |
if err != nil { | |
log.Fatalln(err) | |
} | |
case <-removeCh: | |
err = waitUntilFind(filename) | |
if err != nil { | |
log.Fatalln(err) | |
} | |
err = watcher.Add(filename) | |
if err != nil { | |
log.Fatalln(err) | |
} | |
} | |
} | |
}() | |
log.Fatalln(<-errCh) | |
} |
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