log.Println(r.RemoteAddr, "put", filename, "by", username)
path := filepath.Join(dirPath, filename)
if _, err = os.Stat(path); err == nil {
log.Println(r.RemoteAddr, "put", filename, "by", username)
path := filepath.Join(dirPath, filename)
if _, err = os.Stat(path); err == nil {