Capture 7-Zip output and exit code from a process in VB - vb.net

Question

I have the following VB.NET 4.0 console application that runs 7z.exe in a process and successfully completes with a zipped file:
Public Sub CompressFiles(sZipFileName As String, sDriveLetter As String)
Dim s7ZipCmdArgs As String = ""
Dim myProcess As New Process
Console.WriteLine()
Console.WriteLine("Scanning files...")
'Compress files
s7ZipCmdArgs = " a -r -y -xr!windows\ -xr!$Recycle.Bin\ " + sZipFileName _
+ " " + sDriveLetter + "\*.txt" _
+ " " + sDriveLetter + "\*.doc" _
+ " " + sDriveLetter + "\*.xls" _
+ " " + sDriveLetter + "\*.ppt" _
+ " " + sDriveLetter + "\*.url" _
+ " " + sDriveLetter + "\*.docx" _
+ " " + sDriveLetter + "\*.xlsx" _
+ " " + sDriveLetter + "\*.pptx" _
+ " " + sDriveLetter + "\*.pdf" _
+ " " + sDriveLetter + "\*.wav" _
+ "> C:\test\zipresults.txt"
myProcess.StartInfo.FileName = "C:\test\7-Zip\7z.exe"
myProcess.StartInfo.Arguments = s7ZipCmdArgs
myProcess.StartInfo.WorkingDirectory = "C:\test"
myProcess.StartInfo.UseShellExecute = False
myProcess.StartInfo.CreateNoWindow = True
myProcess.Start()
myProcess.WaitForExit()
End Sub
The code executes fine except for the redirect to a text file: "> C:\test\zipresults.txt" in the s7ZipCmdArgs string variable. I'm not sure why that's not working, I've tried different sets of double and triple quotes without success. It does work in a batch file using the same string.
My second question is: How do I capture the 7Zip exit code so that I can determine if it completed successfully? It returns the following integers: 0 (No errors), 1 (Non fatal error), 2 (Fatal error), 7 (Command line error), 8 (Memory error), and 255 (User error). I'm not sure how to capture the integer so that I can decode it.

Answer 1

For the first part, have you tried adding a space before the > in your command args? You could also check out this answer for capturing the output in code.
For the first part, per this answer you can't redirect the standard output using > when using Process.Start(). So, you will need to remove the redirect from the arguments, set StartInfo.RedirectStandardOutput to true, and then write the output to a file in the OutputDataReceived event. Something like this:
Dim pgm = "C:\Program Files\7-Zip\7z.exe"
Dim args = "l C:\Dev\Test.zip"
Dim myProcess = New Process()
With myProcess.StartInfo
.FileName = pgm
.Arguments = args
.WorkingDirectory = "C:\Dev"
.UseShellExecute = False
.CreateNoWindow = True
.RedirectStandardOutput = True
End With
Using out = New StreamWriter("C:\Dev\test.txt")
AddHandler myProcess.OutputDataReceived,
Sub(sender, e)
out.WriteLine(e.Data)
End Sub
myProcess.Start()
myProcess.BeginOutputReadLine()
myProcess.WaitForExit()
End Using
For the second, myProcess.ExitCode will have the result after the WaitForExit() call.