[RESOLVED] Help on my Process coding

[frankwhite]

Hi,

I have some coding which just runs cmd commands.

 Private Sub RunCMD()
        Dim myProcess As Process = New Process
        Dim s As String
        myProcess.StartInfo.FileName = "c:\windows\system32\cmd.exe"
        myProcess.StartInfo.UseShellExecute = False
        myProcess.StartInfo.CreateNoWindow = True
        myProcess.StartInfo.RedirectStandardInput = True
        myProcess.StartInfo.RedirectStandardOutput = True
        myProcess.StartInfo.RedirectStandardError = True
        myProcess.Start()

        Dim sIn As System.IO.StreamWriter = myProcess.StandardInput
        Dim sOut As System.IO.StreamReader = myProcess.StandardOutput
        Dim sErr As System.IO.StreamReader = myProcess.StandardError

        sIn.AutoFlush = True
        sIn.Write("Insert Command Here" & System.Environment.NewLine)
        sIn.Write("exit" & System.Environment.NewLine)

        s = sOut.ReadToEnd()

        If Not myProcess.HasExited Then
            myProcess.Kill()
        End If
   
        sIn.Close()
        sOut.Close()
        sErr.Close()
        myProcess.Close()

    End Sub

    Private Sub Button11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button11.Click

        Dim processThread As New Threading.Thread(AddressOf RunCMD)
        processThread.IsBackground = True
        processThread.Start()

End Sub

Now the code works perfectly fine but would it be possible to make the coding shorter or is there any extra coding which I can remove?

[Niya]

Not really. What Id do is make a function to create the process object and set its StartInfo before returning the reference. This doesn't actually reduce the amount of code but it would make RunCMD smaller.

[frankwhite]

thanks, one more thing if I wanted to add a cancel button which will kill any process and any cmd what would be the best way?

If possible can you also give me an example?

I was thinking.

  Dim processThread As New Threading.Thread(AddressOf RunCMD)
        processThread.IsBackground = True
        processThread.Abort

but this does not kill the command.

[Niya]

What I'm suggesting is really simple. Basically what I meant is that you can split that procedure into two procedures. One to set up the process object and the other to do that other stuff you wrote:-

'
    Public Function CreateCMDProcess() As Process
 
        Dim myProcess As Process = New Process
 
        myProcess.StartInfo.FileName = "c:\windows\system32\cmd.exe"
        myProcess.StartInfo.UseShellExecute = False
        myProcess.StartInfo.CreateNoWindow = True
        myProcess.StartInfo.RedirectStandardInput = True
        myProcess.StartInfo.RedirectStandardOutput = True
        myProcess.StartInfo.RedirectStandardError = True
 
        Return myProcess
    End Function

You simply call this procedure to return the process thereby reducing the amount of code in RunCMD

[frankwhite]

ok many thanks, what are your thoughts about the cancel button? is that possible?

[Niya]

Your thread doesn't run for long so I don't see a need for a cancel in this case. What are you trying to do there any way ?

[frankwhite]

well some commands that I run will be collecting data, they can run for up to 1 hour at a time so I would need a way of canceling the process if possible.

[Niya]

Then you should widen the scope of myProcess because as it is now, it will go out of scope leaving nothing to reference the process. Also, each process in Windows has its own set of threads so executing RunCMD on a different thread is a bit redundant and you don't seem to be waiting for the process to exit in that thread.