golang調試日誌寫到txt

func log_output(str_content string)  {
   fd,_:=os.OpenFile("a.txt",os.O_RDWR|os.O_CREATE|os.O_APPEND,0644)
   fd_time:=time.Now().Format("2006-01-02 15:04:05");
   fd_content:=strings.Join([]string{"======",fd_time,"=====",str_content,"\n"},"")
   buf:=[]byte(fd_content)
   fd.Write(buf)
   fd.Close()
}