Check if files and directories exist

file_exists.go

func fileExists(filename string) bool {
	_, err := os.Stat(filename)
	return !errors.Is(err, fs.ErrNotExist) 
}

func dirExists(name string) (bool, error) {
	fi, err := os.Stat(name)
	if err != nil {
		if errors.Is(err, fs.ErrNotExist) {
			return false, nil
		}
		return false, err
	}
	if !fi.IsDir() {
		return false, fmt.Errorf("%s is not a directory", name)
	}
	return true, nil
}

func dirEmpty(name string) (bool, error) {
	f, err := os.Open(name)
	if err != nil {
		return false, err
	}
	defer f.Close()

	_, err = f.Readdirnames(1)
	if err == io.EOF {
		return true, nil
	}
	return false, err
}

func fileChanged(filePath string, modTime time.Time) (time.Time, bool, error) {
	fi, err := os.Stat(filePath)
	if err != nil {
		return modTime, false, err
	}
	if fi.ModTime() != modTime {
		return fi.ModTime(), true, nil
	}
	return modTime, false, nil
}