{"id":15361,"date":"2011-03-10T00:01:00","date_gmt":"2011-03-10T00:01:00","guid":{"rendered":"https:\/\/blogs.technet.microsoft.com\/heyscriptingguy\/2011\/03\/10\/use-powershell-to-find-wmi-classes-that-contain-methods\/"},"modified":"2011-03-10T00:01:00","modified_gmt":"2011-03-10T00:01:00","slug":"use-powershell-to-find-wmi-classes-that-contain-methods","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/scripting\/use-powershell-to-find-wmi-classes-that-contain-methods\/","title":{"rendered":"Use PowerShell to Find WMI Classes that Contain Methods"},"content":{"rendered":"

Summary<\/b>: Learn how to use Windows PowerShell to find WMI classes that contain usable methods for making configuration changes in Windows.<\/span><\/p>\n

\"Hey,  Hey, Scripting Guy! I that know you spend a lot of time working with WMI. The one thing that I really do not like about WMI is that although it seems like there is a lot of information that can be retrieved, it seems that there are not very many things that WMI can actually do. I guess what I am really interested in is: Are there WMI classes that have methods?<\/span><\/p>\n

—SH<\/span><\/p>\n

\"Hey, Hello SH, <\/span><\/p>\n

Microsoft Scripting Guy, Ed Wilson, here. It is less than a month until the 2011 Scripting Games, and things are really heating up. While I was in Seattle last week visiting with the Microsoft MVPs, I was able to round up a large number of judges and expert commentators. I have already begun emailing the events to the expert commentators, and I am compiling my list of judges. The judges and the judging criteria will be posted soon. The one location you need to bookmark is the <\/span>2011 Scripting Games: All Links on One Page<\/span><\/a> site. Links to vital information will be presented throughout the next couple of months. <\/span><\/p>\n

While sipping a cup of English Breakfast tea and munching a caramel flavored Tim Tam (provided by Microsoft MVP Shane Hoey from Australia), I finally had a chance to write a script I have been wanting to write for a long time. I had written a similar script for my Microsoft Press book, <\/span>Windows Scripting with WMI<\/span><\/a>, but I used VBScript for that endeavor, and I wanted to update it to Windows PowerShell. <\/span><\/p>\n

One nice change in Windows PowerShell 2.0 is direct access to a methods collection. (In Windows PowerShell 1.0, it was more difficult to obtain this information.) One thing that makes the script a bit complicated is the way that WMI exposes information. <\/span><\/p>\n

In the end, the Get-WmiClassMethods.ps1 script is a bit more complicated than I would like it to be, but it works and it accomplishes the job. Feel free to email improvements to the script to <\/span>scripter@microsoft.com<\/span><\/a>, or better yet, post a revision to the script to the <\/span>Scripting Guys Script Repository<\/span><\/a> so other scripters will have access to your work. <\/span><\/p>\n

The complete Get-WmiClassMethods.ps1 script appears here:<\/span><\/p>\n

Get-WmiClassMethods.ps1<\/span><\/strong><\/p>\n

\n

# —————————————————————————–<\/span><\/span><\/span><\/p>\n

# Script: Get-WmiClassMethods.ps1<\/span><\/span><\/span><\/p>\n

# Author: ed wilson, msft<\/span><\/span><\/span><\/p>\n

# Date: 03\/08\/2011 12:46:15<\/span><\/span><\/span><\/p>\n

# Keywords: Scripting Techniques, WMI<\/span><\/span><\/span><\/p>\n

# comments: Gets dynamic WMI classes that have methods marked with the implemented<\/span><\/span><\/span><\/p>\n

# qualifier<\/span><\/span><\/span><\/p>\n

# HSG-3-10-11<\/span><\/span><\/span><\/p>\n

# —————————————————————————–<\/span><\/span><\/span><\/p>\n

function New-Underline<\/span><\/span><\/span><\/p>\n

{<\/span><\/span><\/span><\/p>\n

<#<\/span><\/span><\/span><\/p>\n

.Synopsis<\/span><\/span><\/span><\/p>\n

 <\/span>Creates an underline the length of the input string<\/span><\/span><\/span><\/p>\n

.Example<\/span><\/span><\/span><\/p>\n

 <\/span>New-Underline -strIN “Hello world”<\/span><\/span><\/span><\/p>\n

.Example<\/span><\/span><\/span><\/p>\n

 <\/span>New-Underline -strIn “Morgen welt” -char “-” -sColor “blue” -uColor “yellow”<\/span><\/span><\/span><\/p>\n

.Example<\/span><\/span><\/span><\/p>\n

 <\/span>“this is a string” | New-Underline<\/span><\/span><\/span><\/p>\n

.Notes<\/span><\/span><\/span><\/p>\n

 <\/span>NAME:<\/span><\/span><\/span><\/p>\n

 <\/span>AUTHOR: Ed Wilson<\/span><\/span><\/span><\/p>\n

 <\/span>LASTEDIT: 5\/20\/2009<\/span><\/span><\/span><\/p>\n

 <\/span>KEYWORDS:<\/span><\/span><\/span><\/p>\n

.Link<\/span><\/span><\/span><\/p>\n

 <\/span>Http:\/\/www.ScriptingGuys.com<\/span><\/span><\/span><\/p>\n

#><\/span><\/span><\/span><\/p>\n

[CmdletBinding()]<\/span><\/span><\/span><\/p>\n

param(<\/span><\/span><\/span><\/p>\n

      <\/span>[Parameter(Mandatory = $true,Position = 0,valueFromPipeline=$true)]<\/span><\/span><\/span><\/p>\n

      <\/span>[string]<\/span><\/span><\/span><\/p>\n

      <\/span>$strIN,<\/span><\/span><\/span><\/p>\n

      <\/span>[string]<\/span><\/span><\/span><\/p>\n

      <\/span>$char = “=”,<\/span><\/span><\/span><\/p>\n

      <\/span>[string]<\/span><\/span><\/span><\/p>\n

      <\/span>$sColor = “Green”,<\/span><\/span><\/span><\/p>\n

      <\/span>[string]<\/span><\/span><\/span><\/p>\n

      <\/span>$uColor = “darkGreen”,<\/span><\/span><\/span><\/p>\n

      <\/span>[switch]<\/span><\/span><\/span><\/p>\n

      <\/span>$pipe<\/span><\/span><\/span><\/p>\n

 <\/span>) #end param<\/span><\/span><\/span><\/p>\n

 <\/span>$strLine= $char * $strIn.length<\/span><\/span><\/span><\/p>\n

 <\/span>if(-not $pipe)<\/span><\/span><\/span><\/p>\n

  <\/span>{<\/span><\/span><\/span><\/p>\n

   <\/span>Write-Host -ForegroundColor $sColor $strIN<\/span><\/span><\/span><\/p>\n

   <\/span>Write-Host -ForegroundColor $uColor $strLine<\/span><\/span><\/span><\/p>\n

  <\/span>}<\/span><\/span><\/span><\/p>\n

  <\/span>Else<\/span><\/span><\/span><\/p>\n

  <\/span>{<\/span><\/span><\/span><\/p>\n

  <\/span>$strIn<\/span><\/span><\/span><\/p>\n

  <\/span>$strLine<\/span><\/span><\/span><\/p>\n

  <\/span>}<\/span><\/span><\/span><\/p>\n

} #end new-underline function<\/span><\/span><\/span><\/p>\n

 <\/span><\/span><\/span><\/p>\n

Function Get-WmiClassMethods<\/span><\/span><\/span><\/p>\n

{ <\/span><\/span><\/span><\/p>\n

 <\/span>Param(<\/span><\/span><\/span><\/p>\n

   <\/span>[string]$namespace = “root\\cimv2”,<\/span><\/span><\/span><\/p>\n

   <\/span>[string]$computer = “.”<\/span><\/span><\/span><\/p>\n

)<\/span><\/span><\/span><\/p>\n

 <\/span>$abstract = $false<\/span><\/span><\/span><\/p>\n

 <\/span>$method = $null<\/span><\/span><\/span><\/p>\n

 <\/span>$classes = Get-WmiObject -List -Namespace $namespace | Where-Object { $_.methods }<\/span><\/span><\/span><\/p>\n

 <\/span>Foreach($class in $classes)<\/span><\/span><\/span><\/p>\n

 <\/span>{<\/span><\/span><\/span><\/p>\n

  <\/span>Foreach($q in $class.Qualifiers)<\/span><\/span><\/span><\/p>\n

   <\/span>{ if ($q.name -eq ‘Abstract’) {$abstract = $true} }<\/span><\/span><\/span><\/p>\n

  <\/span>If(!$abstract) <\/span><\/span><\/span><\/p>\n

    <\/span>{ <\/span><\/span><\/span><\/p>\n

     <\/span>Foreach($m in $class.methods)<\/span><\/span><\/span><\/p>\n

      <\/span>{ <\/span><\/span><\/span><\/p>\n

       <\/span>Foreach($q in $m.qualifiers) <\/span><\/span><\/span><\/p>\n

        <\/span>{ <\/span><\/span><\/span><\/p>\n

         <\/span>if($q.name -match “implemented”) <\/span><\/span><\/span><\/p>\n

          <\/span>{ <\/span><\/span><\/span><\/p>\n

            <\/span>$method += $m.name + “`r`n”<\/span><\/span><\/span><\/p>\n

          <\/span>} #end if name<\/span><\/span><\/span><\/p>\n

        <\/span>} #end foreach q<\/span><\/span><\/span><\/p>\n

      <\/span>} #end foreach m<\/span><\/span><\/span><\/p>\n

      <\/span>if($method) {New-Underline $class.name}<\/span><\/span><\/span><\/p>\n

      <\/span>$method<\/span><\/span><\/span><\/p>\n

    <\/span>} #end if not abstract<\/span><\/span><\/span><\/p>\n

  <\/span>$abstract = $false<\/span><\/span><\/span><\/p>\n

  <\/span>$method = $null<\/span><\/span><\/span><\/p>\n

 <\/span>} #end foreach class<\/span><\/span><\/span><\/p>\n

} #end function Get-WmiClassMethods<\/span><\/span><\/span><\/p>\n

 <\/span><\/span><\/span><\/p>\n

# *** Entry Point to Script ***<\/span><\/span><\/p>\n

 <\/span><\/span><\/p>\n

Get-WmiClassMethods<\/span><\/span><\/span><\/p><\/blockquote>\n

The first thing I do in the Get-WmiClassMethods.ps1 script is to create the New-Underline<\/b> function. I wrote this standard function when I was writing all of the scripts for the <\/span>Windows 7 Resource Kit<\/span><\/a>. I have also used it in a <\/span>number of Hey Scripting Guy! articles<\/span><\/a>; therefore, I will not expound upon it here. <\/span><\/p>\n

In the Get-WmiClassMethods<\/b> function, I first create two input parameters. The first one is used for the WMI namespace, and the second one is for the computer name. Both are set to default parameters. I then initialize two variables that are used later in the function. This portion of the script is shown here.<\/span><\/p>\n

\n

Function Get-WmiClassMethods<\/span><\/span><\/p>\n

{ <\/span><\/span><\/p>\n

Param(<\/span><\/span><\/p>\n

[string]$namespace = “root\\cimv2”,<\/span><\/span><\/p>\n

[string]$computer = “.”<\/span><\/span><\/p>\n

)<\/span><\/span><\/p>\n

$abstract = $false<\/span><\/span><\/p>\n

$method = $null<\/span><\/span><\/p>\n<\/blockquote>\n

There are numerous WMI namespaces, and therefore the ability to change namespaces is an essential technique. In addition, the ability to run the script against a remote computer makes it a valuable tool because various versions of the operating system (and indeed various features and roles) provide access to different classes and namespaces. <\/span><\/p>\n

By using the list <\/i>parameter from the Get-WmiObject<\/b> Windows PowerShell cmdlet, I am able to obtain a listing of all the WMI classes in a namespace. This listing contains abstract classes (that are not usable for scripting), in addition to classes that do not have methods. I use the Where-Object<\/b> cmdlet to limit the results to only WMI classes that have methods. This list is stored in the variable $classes<\/b> as shown here.<\/span><\/p>\n

\n

$classes = Get-WmiObject -List -Namespace $namespace | Where-Object { $_.methods }<\/span><\/span><\/p>\n<\/blockquote>\n

Next I use the foreach <\/i>statement to walk through the array of WMI classes. For each WMI class (stored in the $class<\/b> variable) I look at the collection of qualifiers that are associated with the WMI class. If a WMI class has the abstract<\/i> qualifier, I eliminate it from further consideration and I set the $abstract<\/b> variable to $true<\/b>. This portion of the script is shown here.<\/span><\/p>\n

\n

Foreach($class in $classes)<\/span><\/span><\/p>\n

{<\/span><\/span><\/p>\n

Foreach($q in $class.Qualifiers)<\/span><\/span><\/p>\n

{ if ($q.name -eq ‘Abstract’) {$abstract = $true} }<\/span><\/span><\/p>\n<\/blockquote>\n

If the $abstract<\/b> variable is not set to $true<\/b>, I proceed to obtain a collection of all of the methods that are associated with the WMI class (contained in the $class<\/b> variable). To see if a method will work, I look for a qualifier named implemented.<\/i> If the implemented <\/i>qualifier exists, the method should work. If the method is not implemented, it will not work, and there is no point in returning it to my list. I then create a variable called $method<\/b> to hold all of the implemented method names for each WMI class. This portion of the script is shown here.<\/span><\/p>\n

\n

If(!$abstract) <\/span><\/span><\/p>\n

{ <\/span><\/span><\/p>\n

Foreach($m in $class.methods)<\/span><\/span><\/p>\n

{ <\/span><\/span><\/p>\n

Foreach($q in $m.qualifiers) <\/span><\/span><\/p>\n

{ <\/span><\/span><\/p>\n

if($q.name -match “implemented”) <\/span><\/span><\/p>\n

{ <\/span><\/span><\/p>\n

$method += $m.name + “`r`n”<\/span><\/span><\/p>\n

} #end if name<\/span><\/span><\/p>\n

} #end foreach q<\/span><\/span><\/p>\n

} #end foreach m<\/span><\/span><\/p>\n<\/blockquote>\n

Now it is time to produce the report. I want to list only WMI class names that contain implemented methods. Therefore, I examine the $method<\/b> variable to see if it contains any methods. If it does, I call the New-Underline<\/b> function to underline the WMI class name, and I print the methods that are associated with the class. <\/span><\/p>\n

Next, I need to clean out the $abstract<\/b> and the $method<\/b> variables so I can loop through the script for the next WMI class in the list. To call the script, I can use the function name (Get-WmiClassMethods<\/b>) as I did here, or I can call the Get-WmiClassMethods<\/b> function and pass a different computer and a different WMI namespace to it. This portion of the script is shown here.<\/span><\/p>\n

\n

if($method) {New-Underline $class.name}<\/span><\/span><\/p>\n

$method<\/span><\/span><\/p>\n

} #end if not abstract<\/span><\/span><\/p>\n

$abstract = $false<\/span><\/span><\/p>\n

$method = $null<\/span><\/span><\/p>\n

} #end foreach class<\/span><\/span><\/p>\n

} #end function Get-WmiClassMethods<\/span><\/span><\/p>\n

# *** Entry Point to Script ***<\/span><\/span><\/p>\n

Get-WmiClassMethods<\/span><\/span><\/p>\n<\/blockquote>\n

When the script runs, the output that is shown in the following image appears. <\/span><\/p>\n

\"Image<\/span><\/a><\/p>\n

Improvements to the script could be to add the ability to output to a file (redirection would work) and adding a progress indicator (the script takes several seconds to complete). For more information about WMI, refer to the <\/span>Hey, Scripting Guy! blog<\/span><\/a>. <\/span><\/p>\n

SH, that is all there is to finding WMI classes that can actually do things. In Windows 7, there are some great new additions to WMI. I invite you to join me tomorrow when we will do a similar thing for properties. It will be really cool. <\/span><\/p>\n

I invite you to follow me on <\/span>Twitter<\/span><\/a> and <\/span>Facebook<\/span><\/a>. If you have any questions, send email to me at <\/span>scripter@microsoft.com<\/span><\/a>, or post your questions on the <\/span>Official Scripting Guys Forum<\/span><\/a>. See you tomorrow. Until then, peace.<\/span><\/p>\n

Ed Wilson, Microsoft Scripting Guy<\/span><\/span><\/b><\/p>\n

 <\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Summary: Learn how to use Windows PowerShell to find WMI classes that contain usable methods for making configuration changes in Windows.   Hey, Scripting Guy! I that know you spend a lot of time working with WMI. The one thing that I really do not like about WMI is that although it seems like there […]<\/p>\n","protected":false},"author":595,"featured_media":87096,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[3,4,45,6],"class_list":["post-15361","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-scripting","tag-scripting-guy","tag-scripting-techniques","tag-windows-powershell","tag-wmi"],"acf":[],"blog_post_summary":"

Summary: Learn how to use Windows PowerShell to find WMI classes that contain usable methods for making configuration changes in Windows.   Hey, Scripting Guy! I that know you spend a lot of time working with WMI. The one thing that I really do not like about WMI is that although it seems like there […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/15361","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/users\/595"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/comments?post=15361"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/15361\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media\/87096"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media?parent=15361"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/categories?post=15361"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/tags?post=15361"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}