How to redirect standard output to a file from psexec process in c# within a Windows Forms Application

Question

I've been trying to get the console output from running psexec as a process in a c# windows forms application. I've found I can redirect the standardoutput(and standard error) to a specified text file fine in a console application, and can redirect the output when the process used is something other than PsExec (ping for instance), but when I try to use psexec from a windows forms application I usually get an empty line in my logs, or at best I've been able to get the first line. I know psexec has had issues with synchronous redirected output, but even asychronous runs into this problem, but only when used within a Windows Forms Application.

My code for the method called that runs the process:

class Tester
    {

        static readonly StringBuilder outputText = new StringBuilder();
        static readonly StringBuilder errorText = new StringBuilder();

        public void Installer(string command, string arguments)
        {
            using (var psexec = Process.Start(new ProcessStartInfo(
               command,
                arguments)
            {
                CreateNoWindow = true,
                ErrorDialog = false,
                RedirectStandardError = true,
                RedirectStandardOutput = true,
                UseShellExecute = false
            }))
            {

                psexec.OutputDataReceived += (sendingProcess, outLine) =>
                    outputText.AppendLine(outLine.Data);

                psexec.ErrorDataReceived += (sendingProcess, errorLine) =>
                    errorText.AppendLine(errorLine.Data);

                psexec.BeginOutputReadLine();
                psexec.BeginErrorReadLine();

                psexec.WaitForExit();

                string text = outputText.ToString();
                File.AppendAllText(@"C:\test\psexec-test.log", text);

            }

        }
    }

The above works (gives me the output from psexec I expect in a designated file) when called within a console application like this:

class Program
{
    static void Main(string[] args)
    {
        Tester test1 = new Tester();

        test1.Installer("PsExec.exe", @"-h \\remoteserver ipconfig");
    }
}

However, if I call it from an equivalent Windows Forms Application like so:

public partial class Form1 : Form
{

    Tester test = new Tester();

    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        string sendAddress = Address.Text;
        test.Installer("psexec.exe", @"-h \\remoteserver ipconfig");
    } }

I only get:

Windows IP Configuration

Done! Without the rest of the results from ipconfig.

In the larger application I made everything else does work and I know real work is done (it runs an installer on the remote machine, or multiple remote machines), but I don't get the output from psexec. Is there something I'm missing with the Windows Forms Applications, and how to get the redirection to work with psexec?

Answer 1

Seems like you're jumping the gun on starting the process. It surprises me you're getting what you want in a console app. But I think you want to create your process, hook the events, and then start:

public void Installer( string command, string arguments, string logFile )
{
  var outputText = new StringBuilder( );
  var errorText = new StringBuilder( );

  var startInfo = new ProcessStartInfo( command, arguments )
  {
    CreateNoWindow = true,
    ErrorDialog = false,
    RedirectStandardError = true,
    RedirectStandardOutput = true,
    UseShellExecute = false
  };

  using ( var psexec = new Process( ) )
  {
    psexec.StartInfo = startInfo;
    psexec.OutputDataReceived += ( _, dat ) => outputText.AppendLine( dat.Data );
    psexec.ErrorDataReceived += ( _, dat ) => errorText.AppendLine( dat.Data );
    psexec.Start( );
    psexec.BeginOutputReadLine( );
    psexec.BeginErrorReadLine( );
    psexec.WaitForExit( );

    File.AppendAllText( logFile, outputText.ToString( ) );
  }
}