I have some old code in visual basic script. Instead of re-writing this old code into PowerShell, I'd like to call the VB scripts from PowerShell and capture their return value.
How can I get the return value of a visual basic script in powershell?
Something like this:
$returnValue = Invoke-Command -ScriptBlock{.\vbs\legacyVbsFunction.vbs}
The visual basic function may look like this
Function MyFunction() As Double
Return 3.87 * 2
End Function
It sounds like you want to capture a VBScript's (stdout) output:
$output = cscript.exe //nologo .\vbs\legacyVbsFunction.vbs
Note that $output will either be a single string - if the script outputs just 1 line - or an array of strings in case of multi-line output.
For example, assuming that .\vbs\legacyVbsFunction.vbs contains the following code:
Function MyFunction
MyFunction = 3.87 * 2
End Function
' Call the function and print it to stdout.
Wscript.Echo(MyFunction)
You could capture the output and convert it to a [double] as follows:
[double] $output = cscript.exe //nologo .\vbs\legacyVbsFunction.vbs
$output then contains 7.74.
You can actually embed a vbscript function right in powershell using a com object called ScriptControl, but it only works in 32-bit powershell, C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe: Embed VBS into PowerShell
function Call-VBScript
{
$sc = New-Object -ComObject ScriptControl
$sc.Language = 'VBScript'
$sc.AddCode('
Function MyFunction
MyFunction = 3.87 * 2
End Function
')
$sc.CodeObject
}
$vb = Call-VBScript
$returnvalue = $vb.MyFunction()
"returnvalue is " + $returnvalue
I found out you can run a job as 32-bit:
$returnvalue =
start-job {
function Call-VBScript {
$sc = New-Object -ComObject MSScriptControl.ScriptControl.1
$sc.Language = 'VBScript'
$sc.AddCode('
Function MyFunction
MyFunction = 3.87 * 2
End Function
')
$sc.CodeObject
}
$vb = call-vbscript
$vb.MyFunction()
} -runas32 | wait-job | receive-job
"returnvalue is " + $returnvalue
You don't really have an exit code in the VBS, you have a return for a function. To actually have a return code you must close the script with something like:
wscript.quit(0)
or
wscript.quit(returncode)
In the powershell script you must execute the vbs something like this:
(Start-Process -FilePath "wscript.exe" -ArgumentList "Script.vbs" -Wait -Passthru).ExitCode
Start-Process is not required. PowerShell stores the exit code of the last external command in the automatic variable $LastExitCode. You may need to run VBScripts with cscript.exe instead of the default wscript.exe, though.
wscript.exe can't be used either way, since it doesn't return the exit code (probably because it runs the script asynchronously).-PassThru. Makes sense now. But even so, wscript.exe would only be usable with Start-Process -Wait -PassThru, so I'd still recommend using cscript.exe instead.