How to: Get and Set WMI Object Properties

Article
08/18/2014

This content is no longer actively maintained. It is provided as is, for anyone who may still be using these technologies, with no warranties or claims of accuracy with regard to the most recent product version or service release.

To read and write Windows Management Instrumentation (WMI) object property values, you:

Get and set property and qualifier values.
Load and save configurations.

Getting and Setting Properties on WMI Objects

Use properties to provide information about the characteristics of a WMI object. For more information about Speech Server WMI classes, see Speech Server WMI Classes.

To read property values

Use code similar to the following sample.

Note

All Speech Server classes inherit from the SWbemObject object, which explains why the SWbemObject.Properties_ property is available in the following sample.

Set objMSS = GetObject("winmgmts:root\MSSV2:MSS=@")
' Read each member of SWbemObject.Properties_
For Each p in objMSS.Properties_
' Display the values of the Name and Value properties of the SWbemProperty object  
 If p.IsArray Then
      WScript.Echo p.Name, "=", Join(p.Value)
     Else
      WScript.Echo p.Name, " = ", p.Value
   End If
Next

To write property values of Speech Server objects

To write a property value, you must, at a minimum, retrieve an instance of the class containing the property, assign the property a value, and use the Put_ method to update the value in the object. The following sample gets the MSS object (using the GetObject function), sets the UpperMemoryThreshold property, and saves the change.
```
Set objMSS = GetObject("winmgmts:root\MSSV2:MSS=@")
objMSS.UpperMemoryThreshold=1800
objMSS.Put_()
```

Reading Qualifiers on WMI Objects

A qualifier is a tag that provides additional information about a WMI object, method, or property.

To gain access to a WMI object's qualifiers

Use the SWbemObject.Qualifiers_ property, as shown in the following sample.

Set p = objMSS.Properties_(strProperty)

If strNewValue <> "" Then
    'p is a MSS property variable
    p.Value = strNewValue
Else
    d = p.Qualifiers_("DefaultValue")
    p.Value = d
End If

Loading and Saving Configurations

To load values from a configuration file

Use the VBScript Split function and FileSystemObject to parse the file and read property values, as shown in the following sample.

Use the SWbemObjectProperties_ property to store the values read from the configuration file, and use the SWbemObjectPut_ method to update the server instance with those values.

For Each line in Split(f.ReadAll, vbCrLf)

    ' Omit empty lines and comments
    ' ...
    ' Split line into name and value parts
    ' ...

        Set p = objMSS.Properties_(strName)

        If Not Err Then

            If p.IsArray Then
                p.Value = Join(strValue)
            Else
                p.Value = strValue
            End If

            If Err Then
                WScript.Echo "Failed to assign " & strName & ": " & Err.Description : Err.Clear
            End If

        Else
            WScript.Echo "No such property: " & strName : Err.Clear
        End If
Next

' Update WMI with modified instance
objMSS.Put_

To save a server configuration to a file

Use the SWbemObjectProperties_ property to provide the collection of properties on the server, as shown in the following sample.

Set fso = CreateObject("Scripting.FileSystemObject")
Set f = fso.CreateTextFile(strFilename, true)

' Write all configuration settings
For Each p In objMSS.Properties_
    If p.IsArray Then
        f.WriteLine p.Name & ":" & Join(p.Value)
    Else
        f.WriteLine p.Name & ":" & p.Value
    End If
Next

Use the VBScript WriteLine method to write property values to a file.

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