golang执行命令实时输出(协程通过channel更新数据到主进程)

type Charset string

const (
   UTF8    = Charset("UTF-8")
   GB18030 = Charset("GB18030")
)
//对字符进行转码
func ConvertByte2String(byte []byte, charset Charset) string {
   var str string
   switch charset {
   case GB18030:
      var decodeBytes,_=simplifiedchinese.GB18030.NewDecoder().Bytes(byte)
      str= string(decodeBytes)
   case UTF8:
      fallthrough
   default:
      str = string(byte)
   }
   return str
}

func TestCmdOut(t *testing.T) {
	fmt.Println("start")
	cmdstr := "dir /s C:"
	cmd := exec.Command("cmd","/c",cmdstr)
	fmt.Println("11111111")
	stdout,err := cmd.StdoutPipe()
	if err != nil {
		fmt.Println(err)
		return
	}
	stderr,err := cmd.StderrPipe()
	if err != nil {
		fmt.Println(err)
		return
	}

	err = cmd.Start()

	if err != nil {
		fmt.Println(err)
	}

	stdoutScanner := bufio.NewScanner(stdout)
	stderrScanner := bufio.NewScanner(stderr)
	charset := GB18030

	totalOut := ""
	totalErr := ""
	outChan :=  make(chan string, 10000)
	errChan :=  make(chan string, 10000)
	exeEnd := false
	go func(scanner *bufio.Scanner) {
		for scanner.Scan() {
			stdoutstr := ConvertByte2String(scanner.Bytes(), charset)
			outChan <- stdoutstr
		}
		exeEnd = true
	}(stdoutScanner)

	go func(scanner *bufio.Scanner) {
		for scanner.Scan() {
			stderrstr := ConvertByte2String(scanner.Bytes(), charset)
			errChan <- stderrstr
		}
	}(stderrScanner)

	j := 0
	for {
		for i:=0;i<10000;i++ {
			select {
			case outTemp :=  <- outChan:
				fmt.Println("chan:"+outTemp)
				totalOut += "
" + outTemp
			default:
				fmt.Println(fmt.Sprintf("j:%d",j))
				fmt.Println("direct end")
				goto outexit
			}
		}
		outexit:
		for i:=0;i<10000;i++ {
			select {
			case errTemp := <- errChan:
				totalErr += "
" + errTemp
			default:
				fmt.Println("err direct end")
				goto errexit
			}
		}
		errexit:

		fmt.Println(fmt.Sprintf("totalOut:%s",totalOut))
		fmt.Println(fmt.Sprintf("totalErr:%s",totalErr))
		time.Sleep(1*time.Second)
		fmt.Println(exeEnd)
		if exeEnd {
			j += 1
		}
		if j>=2 {
			break
		}


	}

	err = cmd.Wait()


}