Testing the Script

If you jumped ahead and already tried to execute the final script, you realize that it's flawed. If you haven't, go ahead and give it a whirl now. Take a few minutes to see if you can track down the problem. There are actually three errors, and here are some hints.

• One is a simple typo.

• One is a sort of logic error, where something isn't being used properly for the situation.

• The last one is a typo, and could have been avoided if I had followed my own advice from earlier in the book.

Can you find them all? The first one is an easy mistake: I simply forgot a closing parentheses.

'connect to domain and retrieve

'a list of member objects

Dim oDomain

Set oDomain = GetObject("WinNT://" & sDomain

The correct code should be Set oDomain = GetObject("WinNT://" & sDomain). The next one's a bit trickier.

'open an output file

Dim oOutput

oOutput = oFSO.CreateTextFile("\\server1\public\output.txt")

Can you see it? I'm using oOutput to represent an object, but I forgot to use the Set keyword when making the assignment. VBScript requires Set whenever you're assigning an object to a variable. The corrected code looks like this.

'open an output file

Dim oOutput

Set oOutput = oFSO.CreateTextFile("\\server1\public\output.txt")

The last error is tricky, too. It's in the GetOSInfo() function.

Function GetOSInfo(sComputer)



      'declare variables

      Dim objWMIService

      Dim colItems

      Dim strOutput



      'get WMI service

      Set objWMIService = GetObject("winmgmts:\\" & _

       strComputer & "\root\cimv2")

Did you find it? The problem is that I used the wizard-generated code, which uses "str" as a prefix for string variables. I'm in the habit of using the shorter prefix "s" for string variables, and that's where my problem lies. In the function definition, I declared sComputer, but in the line of code that connects to the WMI service, I used strComputer. I continued using sComputer elsewhere, so strComputer is wrong. Here's the corrected code snippet.

Function GetOSInfo(sComputer)



      'declare variables

      Dim objWMIService

      Dim colItems

      Dim strOutput



      'get WMI service

      Set objWMIService = GetObject("winmgmts:\\" & _

       sComputer & "\root\cimv2")

The problem with this error is that it doesn't cause a problem for the script; the script will execute just fine. You just won't get any results, because the script would try to connect to a computer named "". I mentioned that I could have avoided this problem by following my own advice. Had I included Option Explicit, VBScript would have produced an error on the offending line of code, because strComputer wasn't declared. sComputer, on the other hand, is implicitly declared because it's part of a function declaration. You'll notice that I did the same thing with strOutput and sOutput, meaning they'll have to be corrected, too.

Just to make sure you've got it all, Listing 20.5 includes the complete, corrected script. Remember that this script is also available on the CD that accompanies this book.

Listing 20.5. InventoryDomain2.vbs. This corrected script produces the expected results.

'get domain name

Dim sDomain

sDomain = InputBox("Enter domain to inventory")



'connect to domain and retrieve

'a list of member objects

Dim oDomain

Set oDomain = GetObject("WinNT://" & sDomain)



'get the filesystemobject

Dim oFSO

Set oFSO = CreateObject("Scripting.FileSystemObject")



'open an output file

Dim oOutput

Set oOutput = oFSO.CreateTextFile("\\server1\public\output.txt")



'run through the objects

Dim oObject, sComputerName, sDetails

For Each oObject In oDomain



 'is this object a computer?

 If oObject.Class = "Computer" Then



  'yes - get computer name

  sComputerName = oObject.Name



  'get OS info

  sDetails = GetOSInfo(sComputerName)



  'write info to the file

  oOutput.Write sDetails



 End If

Next

'close the output file

oOutput.Close



'release objects

Set oOutput = Nothing

Set oFSO = Nothing

Set oObject = nothing

Set oDomain = Nothing



'display completion message

WScript.Echo "Output saved to \\server1\public\output.txt"



Function GetOSInfo(sComputer)



      'declare variables

      Dim objWMIService

      Dim colItems

      Dim strOutput



      'get WMI service

      Set objWMIService = GetObject("winmgmts:\\" & _

       sComputer & "\root\cimv2")



      'get item collection

      Set colItems = objWMIService.ExecQuery( _

       "Select * from Win32_OperatingSystem",,48)



      'init output string

      strOutput = String(70,"-")

      strOutput = strOutput & sComputer



      'append info to output string

      For Each objItem in colItems

            strOutput = strOutput & "BuildNumber: " & _

             objItem.BuildNumber & vbCrLf

            strOutput = strOutput & "BuildType: " & _

             objItem.BuildType & vbCrLf

            strOutput = strOutput & "Caption: " & _

             objItem.Caption & vbCrLf

            strOutput = strOutput & "EncryptionLevel: " & _

             objItem.EncryptionLevel & vbCrLf

            strOutput = strOutput & "InstallDate: " & _

             objItem.InstallDate & vbCrLf

            strOutput = strOutput & "Manufacturer: " & _

             objItem.Manufacturer & vbCrLf

            strOutput = strOutput & "MaxNumberOfProcesses: " & _

             objItem.MaxNumberOfProcesses & vbCrLf

      strOutput = strOutput & "MaxProcessMemorySize: " & _

             objItem.MaxProcessMemorySize & vbCrLf

       strOutput = strOutput & "Name: " & _

             objItem.Name & vbCrLf

            strOutput = strOutput & _

             "NumberOfLicensedUsers: " & _

             objItem.NumberOfLicensedUsers & vbCrLf

            strOutput = strOutput & "NumberOfProcesses: " & _

             objItem.NumberOfProcesses & vbCrLf

            strOutput = strOutput & "NumberOfUsers: " & _

             objItem.NumberOfUsers & vbCrLf

            strOutput = strOutput & "OSProductSuite: " & _

             objItem.OSProductSuite & vbCrLf

            strOutput = strOutput & "OSType: " & _

             objItem.OSType & vbCrLf

            strOutput = strOutput & "OtherTypeDescription: " & _

             objItem.OtherTypeDescription & vbCrLf

            strOutput = strOutput & "Primary: " & _

             objItem.Primary & vbCrLf

            strOutput = strOutput & "ProductType: " & _

             objItem.ProductType & vbCrLf

            strOutput = strOutput & "RegisteredUser: " & _

             objItem.RegisteredUser & vbCrLf

            strOutput = strOutput & "SerialNumber: " & _

             objItem.SerialNumber & vbCrLf

            strOutput = strOutput & _

             "ServicePackMajorVersion: " & _

             objItem.ServicePackMajorVersion & vbCrLf

            strOutput = strOutput & _

             "ServicePackMinorVersion: " & _

             objItem.ServicePackMinorVersion & vbCrLf

            strOutput = strOutput & "Version: " & _

             objItem.Version & vbCrLf

            strOutput = strOutput & "WindowsDirectory: " & _

             objItem.WindowsDirectory & vbCrLf

      Next



 'return results

      GetOSInfo = sOutput



End Function

Testing a large script like this is much easier with the Script Debugger. You can spot lines that are causing trouble just by following the execution path.

For more information on the Script Debugger, see "Testing the Script" in Chapter 13. You can also read up on the Script Debugger in the VBScript documentation at http://msdn.microsoft.com/scripting.