c# redirected stderr asking me to type answer. I am not getting question

Question

c# redirected stderr asking me to type answer. I am not getting question

Piotr Rybak 21

I do

    var psi = new ProcessStartInfo
    {
        FileName = "ffmpeg.exe",
        RedirectStandardError = true,
        RedirectStandardOutput = true,
        RedirectStandardInput = true,
        UseShellExecute = false
    };
    var p = Process.Start(psi);
    var reader = p.StandardError;

    while (!reader.EndOfStream) {
        string currentLine = reader.ReadLine();
        File.AppendAllText(fNamestdout, currentLine+"\r\n");
    }

It is getting all lines into file till the last line that awaits for typing into keyboard.
I am not getting the last line with question asking me to type something
so I do not know what answer I should type.

How to get the last line asking me to type something?

Program is blocking at reader.ReadLine(); while awaiting me type answer
but I do not know question.

Daniel Zhang-MSFT 9,661 Reputation points

2021-04-08T05:23:04.55+00:00

Hi @Piotr Rybak ,
Based on your code, I can't reproduce the situation.
In order to understand your problem more accurately, please provide your "ffmpeg.exe" to reproduce the situation.
Best Regards,
Daniel Zhang
josh bauer 6 Reputation points

2021-04-08T09:09:19.86+00:00
var psi = new ProcessStartInfo { FileName = "cmd.exe", RedirectStandardError = false, RedirectStandardOutput = false, RedirectStandardInput = false, UseShellExecute = false }; var p = Process.Start(psi);

I do like above to see command DOS.
But when I write RedirectStandardInput = true.

I am not getting anything on screen. Where is command prompt asking me to type something?
How to read it?
Daniel Zhang-MSFT 9,661 Reputation points

2021-04-08T09:31:50.013+00:00

Hi @josh bauer ,
By redirecting the StandardInput stream, you can programmatically specify the input of a process.
Please refer to the code example in this document.
Best Regards,
Daniel Zhang
josh bauer 6 Reputation points

2021-04-08T14:59:40.92+00:00

But where is MESSAGE from cmd asking me to to type something?
It is not in StandardError, not in StandardOutput, not in StandardInput.
I read them with

var reader = p.StandardError;
while (!reader.EndOfStream) {
string currentLine = reader.ReadLine();
File.AppendAllText(fNamestdout, currentLine+"\r\n");
}

AND

var reader = p.StandardOutput;
while (!reader.EndOfStream) {
string currentLine = reader.ReadLine();
File.AppendAllText(fNamestdout, currentLine+"\r\n");
}

It is not there so I do not know is program asking me to type.

Your answer

Daniel Zhang-MSFT 9,661 Reputation points

2021-04-08T05:23:04.55+00:00

Hi @Piotr Rybak ,
Based on your code, I can't reproduce the situation.
In order to understand your problem more accurately, please provide your "ffmpeg.exe" to reproduce the situation.
Best Regards,
Daniel Zhang
josh bauer 6 Reputation points

2021-04-08T09:09:19.86+00:00

var psi = new ProcessStartInfo { FileName = "cmd.exe", RedirectStandardError = false, RedirectStandardOutput = false, RedirectStandardInput = false, UseShellExecute = false }; var p = Process.Start(psi);

I do like above to see command DOS.
But when I write RedirectStandardInput = true.

I am not getting anything on screen. Where is command prompt asking me to type something?
How to read it?
Daniel Zhang-MSFT 9,661 Reputation points

2021-04-08T09:31:50.013+00:00

Hi @josh bauer ,
By redirecting the StandardInput stream, you can programmatically specify the input of a process.
Please refer to the code example in this document.
Best Regards,
Daniel Zhang
josh bauer 6 Reputation points

2021-04-08T14:59:40.92+00:00

But where is MESSAGE from cmd asking me to to type something?
It is not in StandardError, not in StandardOutput, not in StandardInput.
I read them with

var reader = p.StandardError;
while (!reader.EndOfStream) {
string currentLine = reader.ReadLine();
File.AppendAllText(fNamestdout, currentLine+"\r\n");
}

AND

var reader = p.StandardOutput;
while (!reader.EndOfStream) {
string currentLine = reader.ReadLine();
File.AppendAllText(fNamestdout, currentLine+"\r\n");
}

It is not there so I do not know is program asking me to type.

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c# redirected stderr asking me to type answer. I am not getting question

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