code: func echoOn(fd []uintptr) {
  	// Turn on the terminal echo.
  	pid, e := syscall.ForkExec(sttyArg0, sttyArgvEOn, &syscall.ProcAttr{Dir: execCWDir, Files: fd})
  
  	if e == nil {
  		_, _ = syscall.Wait4(pid, &ws, 0, nil)
  	}
  }
docs: // echoOn turns back on the terminal echo.