reload.go

package main

import (
	"fmt"
	"github.com/fsnotify/fsnotify"
	"os"
	"io"
)

func main() {
	const configFile = "/test/test.txt"

	w, err := fsnotify.NewWatcher()
	if err != nil {
		panic(err)
	}

	defer w.Close()

	err = w.Add(configFile)
	if err != nil {
		panic(err)
	}

	for {
		select {
		case event, ok := <-w.Events:
			if !ok {
				return
			}
			if event.Op == fsnotify.Remove {
				w.Remove(event.Name)
				w.Add(configFile)
				fmt.Println("Remove (reload)")
				reload(configFile)
			}
			if event.Op&fsnotify.Write == fsnotify.Write {
				fmt.Println("Write (reload)")
				reload(configFile)
			}
			fmt.Println("event:", event)
		case err, ok := <-w.Errors:
			if !ok {
				return
			}
			fmt.Println("error:", err)
		}
	}
}

func reload(name string) {
	f, _ := os.Open(name)
	defer f.Close()
	buf, _ := io.ReadAll(f)
	fmt.Println("content:", string(buf))
}