Asynchronously Read Cmd Output In .net - Hanging On Process Input Request

[madlan]

I'm asynchronously reading the output from a batch file, after starting it with some parameters. If the batch file is waiting for input - the input request text is not being redirected - unless the process is terminated (which is obviously too late to respond).

If executed in a standard cmd window, the prompt is:

OpenEdge Release 10.2B07 as of Fri Sep 7 02:16:54 EDT 2012
testdb already exists.
Do you want to over write it? [y/n]:


The output when using redirect will hang, without triggering the outputdatarecieved event, so I cannot process the input request and respond accordingly. The console does not read the last line (input request):

OpenEdge Release 10.2B07 as of Fri Sep 7 02:16:54 EDT 2012
testdb already exists.


Code:

Private Sub someMethod()
Dim process As New Process()
process.StartInfo = New ProcessStartInfo("C:\OEV10\bin\_dbutil")
process.StartInfo.WorkingDirectory = "C:\Temp\"
process.StartInfo.Arguments = "prorest testdb C:\Temp\testdb.bck -verbose"
process.EnableRaisingEvents = True

With process.StartInfo
.UseShellExecute = False
.RedirectStandardError = True
.RedirectStandardOutput = True
.RedirectStandardInput = True
.CreateNoWindow = False
.StandardOutputEncoding = System.Text.Encoding.GetEncoding(Globalization.CultureInfo.CurrentUICulture.TextInfEMCodePage)
.StandardErrorEncoding = System.Text.Encoding.GetEncoding(Globalization.CultureInfo.CurrentUICulture.TextInfEMCodePage)
End With

AddHandler process.Exited, AddressOf ProcessExited
AddHandler process.OutputDataReceived, AddressOf Async_Data_Received2
AddHandler process.ErrorDataReceived, AddressOf Async_Data_Received2

process.Start()
process.BeginOutputReadLine()
process.BeginErrorReadLine()
End Sub

Private Sub Async_Data_Received2(ByVal sender As Object, ByVal e As DataReceivedEventArgs)
Console.WriteLine(e.Data)
End Sub

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