bug： katana execution cannot be started without closing the standard input pipe

[hktalent]

projectdiscovery/nuclei#4560

same bug

var re1 = regexp.MustCompile(` +`)

func testCmd(s string, data string) {
	a := re1.Split(s, -1)
	//log.Println(strings.Join(a, "\n"))
	Cmd := exec.Command(a[0], a[1:]...)
	var err error
	var wt io.WriteCloser
	var wg sync.WaitGroup
	wg.Add(2)
	if wt, err = Cmd.StdinPipe(); nil == err {
		bufout := bufio.NewWriter(wt)
		go func() {
			defer wg.Done()
			bufout.Write([]byte(data + "\n"))
			/*
				I am not in a hurry to close wt here, there will be more uses in the future
				At this point I hope nuclei has started running and output the results
				But we found that if wt is not closed here, http will hang and will never start execution.
				In other words, it will not friendly process and execute the stream from time to time.
				When the stream becomes larger one by one, it will cause memory overflow, the same problem., tlsx does not have this problem. It can process the stream line by line in a friendly manner without waiting for the stream to be closed.
			*/
			bufout.Flush()
			//wt.Close()
		}()
	} else {
		fmt.Println(err)
	}
	if out, err1 := Cmd.StdoutPipe(); nil == err1 {
		go func() {
			defer wg.Done()
			buf := make([]byte, 4096) // 设置适当的缓冲区大小
			for {
				n, err8 := out.Read(buf)
				if 0 < n {
					os.Stdout.Write(buf[:n])
				}
				if err8 == io.EOF {
					break
				}
				if err8 != nil {
					log.Println(err8)
					break
				}
			}
		}()
	} else {
		log.Println(err)
	}
	if err4 := Cmd.Start(); nil != err4 {
		log.Println("Cmd.Start", err4)
	}

	if err6 := Cmd.Wait(); nil != err6 {
		log.Println("Cmd.Wait", err6)
	}
	wg.Wait()
	wt.Close()
}
func TestKatana(t *testing.T) {
	testCmd("katana -nc -silent -j -hl -system-chrome -headless-options '--blink-settings=\"imagesEnabled=false\",--enable-quic=\"imagesEnabled=false\"' -jc -kf all", "https://51pwn.com")
}

If it can friendly support line-by-line processing stream
This helps parse the results in one pass, including the results of other programs, and then give them continuous input of some parameters that need to be iterated over