Processinfo and Redirectstandardoutput

ProcessInfo and RedirectStandardOutput

I've experienced this before. Sometimes, the way in which the process you're calling outputs to the console is not compatible with this sort of output redirection. I've been fortunate enough in this case to be able to modify the external process to get around this.

You might try running your code on another process that outputs to the console, and see if it works properly. It reads about right to me right now.

EDIT:

I went and pulled a code block I've used to do this. This is in a WPF app which redirects the process output to the window. Notice the event binding. Since this is WPF I have to invoke my call to write the data out. Since you aren't worried about blocking, ou should be able to simply replace that with:

Console.WriteLine(e.Data);

Hopefully it helps!

    private static void LaunchProcess()
    {
        Process build = new Process();
        build.StartInfo.WorkingDirectory =  @"dir";
        build.StartInfo.Arguments = "";
        build.StartInfo.FileName = "my.exe";

        build.StartInfo.UseShellExecute = false;
        build.StartInfo.RedirectStandardOutput = true;
        build.StartInfo.RedirectStandardError = true;
        build.StartInfo.CreateNoWindow = true;
        build.ErrorDataReceived += build_ErrorDataReceived;
        build.OutputDataReceived += build_ErrorDataReceived;
        build.EnableRaisingEvents = true;
        build.Start();
        build.BeginOutputReadLine();
        build.BeginErrorReadLine();
        build.WaitForExit();
    }

    // write out info to the display window
    static void build_ErrorDataReceived(object sender, DataReceivedEventArgs e)
    {
        string strMessage = e.Data;
        if (richTextBox != null && !String.Empty(strMessage))
        {
            App.Instance.Dispatcher.BeginInvoke(DispatcherPriority.Send, (ThreadStart)delegate()
            {
                Paragraph para = new Paragraph(new Run(strMessage));
                para.Margin = new Thickness(0);
                para.Background = brushErrorBrush;
                box.Document.Blocks.Add(para);
            });
       }
    } 

Workaround mutually exclusive UseShellExecute and RedirectStandardOutput

I don't see why you want to set UseShellExecute to true. It needs to be false to allow redirection of the standard IO channels

If the location of the perl compiler executable is in PATH then you can just set FileName to perl. It's also better to use String.Format to build strings out of variables rather than use all those escaped quotes and concatenations

Dim myProcess As New System.Diagnostics.Process
myProcess.StartInfo.WorkingDirectory = "K:\Engineering\Temp\perl"
myProcess.StartInfo.UseShellExecute = False
myProcess.StartInfo.FileName = "perl"
myProcess.StartInfo.Arguments = String.Format(
        "perlcompare.pl ""{0}"" ""{1}"" ""{2}""",
        MasterFile,
        MasterOutput,
        ComparisonsOutput)
myProcess.StartInfo.RedirectStandardOutput = True
myProcess.Start()

If the location of the perl compiler isn't in the PATH then you can just put a fully-qualified file path into FileName

Redirect a process's output to both a file and the console

Could use something like that

using System;
using System.Diagnostics;

    namespace InteractWithConsoleApp
    {
        class Program
        {
            static void Main(string[] args)
            {
                ProcessStartInfo cmdStartInfo = new ProcessStartInfo();
                cmdStartInfo.FileName = @"C:\Windows\System32\cmd.exe";
                cmdStartInfo.RedirectStandardOutput = true;
                cmdStartInfo.RedirectStandardError = true;
                cmdStartInfo.RedirectStandardInput = true;
                cmdStartInfo.UseShellExecute = false;
                cmdStartInfo.CreateNoWindow = true;

                Process cmdProcess = new Process();
                cmdProcess.StartInfo = cmdStartInfo;
                cmdProcess.ErrorDataReceived += cmd_Error;
                cmdProcess.OutputDataReceived += cmd_DataReceived;
                cmdProcess.EnableRaisingEvents = true;
                cmdProcess.Start();
                cmdProcess.BeginOutputReadLine();
                cmdProcess.BeginErrorReadLine();

                cmdProcess.StandardInput.WriteLine("ping google.com.ua");     //Execute ping google.com.ua
                cmdProcess.StandardInput.WriteLine("exit");                  //Execute exit.

                cmdProcess.WaitForExit();
            }

            static void cmd_DataReceived(object sender, DataReceivedEventArgs e)
            {
                Console.WriteLine("Output from other process");
                Console.WriteLine(e.Data);
            }

            static void cmd_Error(object sender, DataReceivedEventArgs e)
            {
                Console.WriteLine("Error from other process");
                Console.WriteLine(e.Data);
            }
        }
    }

Redirect standard output and prompt for UAC with ProcessStartInfo

UseShellExecute must be set to false to redirect IO, and to true to use the Verb property. So you can't.

But this article seems do the magic, although I haven't tested it.

It's written in C++, but a wrapper API can easily be created to be called from C# by using DllImport.

Note: If you want to pass data between the two programs and have access to the target program's source code, you can easily re-design you application to use Named Pipes instead of redirecting standard I/O.

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