Run CMD in VB.Net using files as StandardInput and StandardOutput - vb.net

Question

I'm trying to run a command in VB.Net such as:
my_program.exe < input_commands.txt > console_outputs.txt
I tried using the RedirectStandardInput :
myProcessStartInfo.FileName = programPath
myProcessStartInfo.RedirectStandardInput = True
myprocess.StartInfo = myProcessStartInfo
myprocess.Start()
And a StreamWriter to input my text file :
Dim myStreamWriter As StreamWriter = myprocess.StandardInput
For Each Line As String In System.IO.File.ReadLines(processInputFile)
myStreamWriter.WriteLine(Line)
Next
myStreamWriter.Close()
And a similar approach to get the ouputs to a file text :
startInfo.RedirectStandardOutput = True
Dim output As String = Process.StandardOutput.ReadToEnd()
But results are quite limited...
Could you please guide me toward a proper solution?

Answer 1

What I would do is, first read all the lines from the input_commands.txt file into mem:
Private Sub ReadInputFile(programPath as String, processInputFile as String, processOuputFile as String)
' Open the file to read from.
Dim readText() As String = File.ReadAllLines(processInputFile)
For Each s As String In readText
' Run the command through the cmd process
OutPutResults(programPath, s, processOuputFile)
Next
End Sub
and output (append) the results to console_output.txt:
Private Sub OutPutResults(programPath as String, strArgument as String, processOuputFile as String)
Dim p As New Process()
' Set it to run hidden from user
With p.StartInfo
.RedirectStandardOutput = True
.RedirectStandardError = True
.FileName = programPath
.Arguments = strArgument
.UseShellExecute = False
.CreateNoWindow = True
End With
p.Start()
' Save all output to the variable "strOutput"
Dim strOutput As String = p.StandardOutput.ReadToEnd()
' Wait for programPath .exe to finish before we handle it's output:
' (Sync method, meaning the thread won't continue until this one is finished. Use .exited if wanting to do Async)
' Also note that you can add a timeout in milliseconds to this if wanted. i.e. .WaitForExit(1000)
p.WaitForExit()
' Save the output to console_output.txt
File.AppendAllText(processOuputFile, strOutput)
End Sub
Note the above code is completely untested; I just whipped it up to give you the idea.

Answer 2

I wrote the following function that does the trick :
Sub runProgrammCommandsInputFileResultsOutputFile(ByVal myProcessStartInfo As ProcessStartInfo, ByVal myProcess As Process, ByVal programPath As String, ByVal commandsInputFile As String, ByVal resultsOutputFile As String)
myProcessStartInfo.FileName = programPath
myProcessStartInfo.RedirectStandardInput = True
myProcessStartInfo.RedirectStandardOutput = True
myProcessStartInfo.RedirectStandardError = True
myProcessStartInfo.UseShellExecute = False
myProcessStartInfo.CreateNoWindow = True
myProcess.StartInfo = myProcessStartInfo
myProcess.Start()
' Read commands from text file
Dim readCommandsInputFile() As String = System.IO.File.ReadAllLines(commandsInputFile)
' Open StreamWriter to StandardInput
Dim myStreamWriter As StreamWriter = myProcess.StandardInput
' Write read commands to Streamwriter openned to StandardInput
For Each s As String In readCommandsInputFile
myStreamWriter.WriteLine(s)
Next
myStreamWriter.Close()
'Read StandardOutput
Dim resultsOutputStrings As String = myProcess.StandardOutput.ReadToEnd()
' Write StandardOutput read to text file
System.IO.File.AppendAllText(resultsOutputFile, resultsOutputStrings)
End Sub