Why does redirecting standard input cause stdout not to be printed in the new console process?

So, I am trying to start a separate program using Process.Start () .

The program is temporarily suspended and waiting for input. I want to be able to send information to this process on standard input.

I am trying to understand the difference between creating a new process using the Windows shell and the standard input redirection effects.

Exe                 UseShell    RedirectSTDIN  WINDOW Displays  OutputDisplays
cmd.exe /c program     Y               N             Y                Y
                       N               N             Y                Y
                       N               Y             Y                N

program.exe            Y               N             Y                Y
                       N               N             Y                Y
                       N               Y             Y                N

      

        
        
        
      

    

The only important information is that if I redirect stdin, no data is displayed on the screen.

Why is this so?

Usually program.exe

it should be written to the file descriptor stdout

.

I am assuming it Process.Start()

creates a console process. According to MSDN :

Creating a new console creates a new console window as well as separate I / O screen buffers.

I am assuming this new window contains the console and displays the data in the console buffer. Thus, if the program outputs to stdout

, we should see this data on the screen.

This is normal. Why does stdin redirection result in nothing being displayed on the screen even though I don't touch stdout redirection?

edit:

       startInfo.WindowStyle = ProcessWindowStyle.Normal;
        //startInfo.FileName = Path.Combine(BinaryDirectory, "program.exe");
        startInfo.FileName = "cmd.exe";
        startInfo.CreateNoWindow = false;

        //startInfo.Arguments = "";
        startInfo.Arguments = "/C program.exe" + startInfo.Arguments;
        startInfo.UseShellExecute = false;
        startInfo.RedirectStandardInput = true;
        startInfo.RedirectStandardOutput = true;

      

        
        
        
      

    

According to the documentation here: https://msdn.microsoft.com/en-us/library/windows/desktop/ms681953(v=vs.85).aspx

A process can use the AttachConsole function to attach to the console. The process can be connected to one console. A console can have many processes attached to it.

I thought my process could just connect to the console used by the simulator and then I can write to the console. However, it returns error code 6: The console handle is not valid.