CODEWITHSUNDEEP
windows-7powershell-2.0
Davor Josipovic
Davor Josipovic

Reputation: 5504

Get-WmiObject with and without -list: different objects?

I am using PowerShell 2.0 and trying to get the possible methods from Win32_ShadowCopy.

Now, when I use Get-WmiObject -list Win32_ShadowCopy | Get-Member I get:

   TypeName: System.Management.ManagementClass#ROOT\cimv2\Win32_ShadowCopy

Name                MemberType    Definition
----                ----------    ----------
Name                AliasProperty Name = __Class
Create              Method        System.Management.ManagementBaseObject Cre...
...

But if I use Get-WmiObject Win32_ShadowCopy | Get-Member i get:

   TypeName: System.Management.ManagementObject#root\cimv2\Win32_ShadowCopy

Name                MemberType   Definition
----                ----------   ----------
Revert              Method       System.Management.ManagementBaseObject Reve...
Caption             Property     System.String Caption {get;set;}
...

Now I don't understand. Why do I get 2 seemingly different classes? I expect the same result with both commands. I can find what -list does in the documentation, but not what the default behavior is without the -list switch. Anyone care to clarify?

Upvotes: 1

Views: 1360

Answers (2)

terry
terry

Reputation: 1587

This is from get-help about list.

-List [] Specifies whether to retrieve and display the names of the WMI classes in the WMI repository namespace that is specified in the Namespace para meter. The Default Namespace registry entry in the HKEY_LOCAL_MACHINE\ SOFTWARE\Microsoft\WBEM\Scripting registry key is not used by this cmdl et to determine the default namespace. If you specify the List paramete r but not the Namespace parameter, the root\CIMV2 namespace is used by default.

Required?                    false
Position?                    named
Default value
Accept pipeline input?       false
Accept wildcard characters?  false

for your script

Get-WmiObject -list Win32_ShadowCopy

equals:

Get-WmiObject -list -class Win32_ShadowCopy

which means you're listing classes with name Win32_ShadowCopy.

And the 

Get-WmiObject Win32_ShadowCopy

equals:

Get-WmiObject -Class Win32_ShadowCopy

which returns the objects of the specified class.

Upvotes: 2

BartekB
BartekB

Reputation: 8660

Get-WmiObject by default will return instances of the given class. Get-WmiObject -List on the other hand will return class itself. Latter is mainly useful when wildcards are used (e.g. to list all classes in default - root\cimv2 namespace with Disk in name you can do Get-WmiObject -Class *Disk* -List).

Upvotes: 1

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