C# Show output of Process in real time [duplicate]

Question

This question already has answers here:

Redirect console output to textbox in separate program (5 answers)

C# - Capturing Windows Application Output (3 answers)

Closed 6 years ago.

In C# I am starting a 3rd party application that takes 2 - 3 hours to complete. I need the output of the Process to write to the console in real time. I have done research on BeginOutputReadLine() and RedirectStandardOutput from Microsoft's website but my code is still not working.

Currently my code is only showing the output when the process is finished. I don't know where its gone wrong.

static void Main(string[] args)
{
  Process process;
  process = new Process();
  process.StartInfo.FileName = "C:\\ffmbc\\ffmbc.exe";
  process.StartInfo.Arguments = "-i \\\\dssp-isi-t\\TMD\\B002C010_130520_R2R7.2398v5.mxf -an -vcodec libx264 -level 4.1 -preset veryslow -tune film -x264opts bluray-compat=1:weightp=0:bframes=3:nal-hrd=vbr:vbv-maxrate=40000:vbv-bufsize=30000:keyint=24:b-pyramid=strict:slices=4:aud=1:colorprim=bt709:transfer=bt709:colormatrix=bt709:sar=1/1:ref=4 -b 30M -bt 30M -threads 0 -pass 1 -y \\\\dss-isi-t\\MTPO_Transfer\\dbay\\B002C010_130520_R2R7.2398v5.mxf.h264";
  process.StartInfo.UseShellExecute = false;
  process.StartInfo.CreateNoWindow = true;
  process.StartInfo.RedirectStandardOutput = true;
  process.OutputDataReceived += new DataReceivedEventHandler(OutputHandler);
  process.StartInfo.RedirectStandardInput = true;
  process.Start();
  process.BeginOutputReadLine();
  process.WaitForExit();
  process.Close();
}

private static void OutputHandler(object sendingProcess, DataReceivedEventArgs outLine)
{
  string line;
  line = (outLine.Data.ToString());
  Console.WriteLine(line);
}

Answer 1

Similar to a previous question I'd answered, maybe even a duplicate. See: Pipe a stream to Debug.Write()

Here's my answer (modified slightly) from that:

process.StartInfo.UseShellExecute = false; 
process.StartInfo.RedirectStandardOutput = true;
process.OutputDataReceived += p_OutputDataReceived;
process.Start();
process.BeginOutputReadLine();

Then, your event handler for receiving data.

void p_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
    Console.Write(e.Data);
}

Basically, you just need to nix the WaitForExit(), since that makes your program hang until the process completes.

Answer 2

The line

process.WaitForExit();

will cause the current program to wait until the given process finishes. This is most certainly not what you want; you probably want to start the process, let it run asynchronously, and then let it tell you when it finishes. For that, you will want to use the process.Exited event.