Process.start: how to get the output?

stighy picture stighy · Nov 27, 2010 · Viewed 310.1k times · Source

I would like to run an external command line program from my Mono/.NET app. For example, I would like to run mencoder. Is it possible:

  1. To get the command line shell output, and write it on my text box?
  2. To get the numerical value to show a progress bar with time elapsed?

Answer

Ferruccio picture Ferruccio · Nov 27, 2010

When you create your Process object set StartInfo appropriately:

var proc = new Process 
{
    StartInfo = new ProcessStartInfo
    {
        FileName = "program.exe",
        Arguments = "command line arguments to your executable",
        UseShellExecute = false,
        RedirectStandardOutput = true,
        CreateNoWindow = true
    }
};

then start the process and read from it:

proc.Start();
while (!proc.StandardOutput.EndOfStream)
{
    string line = proc.StandardOutput.ReadLine();
    // do something with line
}

You can use int.Parse() or int.TryParse() to convert the strings to numeric values. You may have to do some string manipulation first if there are invalid numeric characters in the strings you read.