Question

I seem to have created an “immortal” process with the following piece of code:

System.Diagnostics.ProcessStartInfo test = new ProcessStartInfo("cmd", " /c " + aCommandLine); //aCommandLine is : ruby test.rb
test.CreateNoWindow = true;
test.RedirectStandardError = true;
test.RedirectStandardOutput = true;
test.UseShellExecute = false;
test.WorkingDirectory = System.IO.Path.GetDirectoryName(aRTextFilePath);
System.Diagnostics.Process aProcess = Process.Start(test);
aProcess.EnableRaisingEvents = true;
aProcess.Exited += new EventHandler(aProcess_Exited);
try
{
    //read synchronously to get the port number
    string aPortInformationLine = aProcess.StandardOutput.ReadLine();
    if (!aProcess.HasExited)
    {
        aProcess.Kill();
        Debug.Print("Process Has Exited");
    }
    //return true;
    errorOut = String.Format("Could not start process with command line : {0} from .rtext file {1}", aCommandLine, aRTextFilePath);
    port = -1;
    return false;
}
catch (Win32Exception ex)
{
    Debug.WriteLine(ex.NativeErrorCode.ToString());
    errorOut = String.Format("Could not start process with command line : {0} from .rtext file {1}. Error : {2}", aCommandLine, aRTextFilePath, ex.NativeErrorCode.ToString());
}
catch (Exception ex)
{
    Debug.WriteLine(ex.Message);
    errorOut = String.Format("Could not start process with command line : {0} from .rtext file {1}. Error : {2}", aCommandLine, aRTextFilePath, ex.Message);
}

So I am using cmd to start a ruby server of some sort. The process starts, and I am able to read output from the newly created process. However when the kill command is executed , no exceptions are thrown but the ruby process doesn’t die.

Does this have anything to do with using the cmd ? Am I doing something else wrong? Thanks

Edit:

I used process explorer and took 2 pics before and after the kill:

Before:

After:

So while cmd.exe dies , ruby somehow manages to go on and live to see another day..

Edit2:

Answer to my problem: Kill process tree programmatically in C#

Answer 1

Your hope that killing the command processor will also kill any process started by it is an idle one, Windows just doesn’t work that way. There is a mechanism for it in Windows, job objects, but you don’t want to go there. Simply don’t use cmd.exe, it doesn’t add any value. Start ruby.exe directly.