#requires -version 2.0


# -----------------------------------------------------------------------------
# Script: Get-WMINamespace-v2.ps1
# Author: Jeffery Hicks 
#    http://jdhitsolutions.com/blog
#    http://twitter.com/JeffHicks
#    http://www.scriptinggeek.com
# Date: 6/15/2011
# Keywords: WMI, Namespace, Invoke-Expression
# Comments:
#
# -----------------------------------------------------------------------------

Function Get-WmiNamespace {

<#
.SYNOPSIS
Get WMI Namespaces
.DESCRIPTION
This command uses WMI to query a machine and return namespaces. Without any parameters it will return the top level namespaces. Or you can use -Recurse to list all namespaces.
.PARAMETER Computername
THe name of the computer to query. The default is the localhost. The parameter has
an alias of 'Name'.
.PARAMETER Credential
A saved PSCredential object or a username which will be used to create a PSCredential.
.PARAMETER Recurse
Recurse through all namespaces
.EXAMPLE
PS C:\> Get-WMINamespace
Computername                   Namespace                               Name
------------                   ---------                               ----
SERENITY                       ROOT\Policy                             Policy
SERENITY                       ROOT\Interop                            Interop
SERENITY                       ROOT\WMI                                WMI
SERENITY                       ROOT\directory                          directory
SERENITY                       ROOT\Microsoft                          Microsoft
SERENITY                       ROOT\aspnet                             aspnet
SERENITY                       ROOT\ServiceModel                       ServiceModel
SERENITY                       ROOT\SecurityCenter                     SecurityCenter
SERENITY                       ROOT\RSOP                               RSOP
SERENITY                       ROOT\CIMV2                              CIMV2
SERENITY                       ROOT\Cli                                Cli
SERENITY                       ROOT\subscription                       subscription
SERENITY                       ROOT\DEFAULT                            DEFAULT
SERENITY                       ROOT\snmp                               snmp
SERENITY                       ROOT\SecurityCenter2                    SecurityCenter2
SERENITY                       ROOT\nap                                nap
SERENITY                       ROOT\SECURITY                           SECURITY

Get top level namespaces on the local host.
.EXAMPLE
PS C:\> Get-WMINamespace -computername "JDHIT-DC01" -cred $jdhit -recurse | Select Namespace

Namespace
---------
ROOT
ROOT\aspnet
ROOT\CIMV2
ROOT\CIMV2\Applications
ROOT\CIMV2\Applications\MicrosoftIE
ROOT\Cli
ROOT\DEFAULT
ROOT\directory
ROOT\directory\LDAP
ROOT\Microsoft
ROOT\Microsoft\HomeNet
ROOT\MicrosoftActiveDirectory
ROOT\MicrosoftDNS
ROOT\MicrosoftIISv2
ROOT\MicrosoftNLB
ROOT\MSCluster
ROOT\perfmon
ROOT\Policy
ROOT\RSOP
ROOT\RSOP\Computer
ROOT\RSOP\User
ROOT\RSOP\User\S_1_5_21_805063240_3875113082_2769008284_500
ROOT\SECURITY
ROOT\ServiceModel
ROOT\snmp
ROOT\snmp\localhost
ROOT\subscription
ROOT\WMI

Connect to JDHIT-DC01 using the saved credential and get all namespaces
.NOTES
NAME        :  Get-WmiNamespace
VERSION     :  2.0   
LAST UPDATED:  6/16/2011
AUTHOR      :  Jeffery Hicks
.LINK
http://jdhitsolutions.com/blog/2011/06/get-wmi-namespace/
.LINK
Get-WmiObject 
Invoke-Expression
.INPUTS
String
.OUTPUTS
Custom Object
#>

[cmdletBinding()]

Param(
    [Parameter(Position=0,Mandatory=$False,ValueFromPipeline=$True,ValueFromPipelineByPropertyName=$True)]
    [ValidateNotNullorEmpty()]
    [Alias("name")]
    [string]$Computername=$env:computername,
    [object]$Credential,
    [switch]$Recurse
)

Begin {
    Write-Verbose -Message "$(Get-Date) Starting $($myinvocation.mycommand)"
    #convert credential to a PSCredential if a string was passed.
    if ( $Credential -is [system.management.automation.psCredential]) {
		Write-Verbose "$(Get-Date) Using PSCredential for $($credential.username)"
	}
	ElseIf ($Credential) {
		Write-Verbose "$(Get-Date) Getting PSCredential for $credential"
		$Credential=Get-Credential $credential
	}
    
 } #close Begin

Process {

    #create a command string. PacketPrivacy is required for some namespaces
    #like MicrosoftTPM
    $cmd="Get-WMIObject -computername $computername -Namespace 'Root' -class '__Namespace' -authentication 'PacketPrivacy' -errorAction 'Stop'"
    
    if ($recurse) {
     $cmd+=" -List -Recurse"
    }
    
    if ($Credential) {
     $cmd+=" -credential `$Credential"
    }
    
Try 
{  
    Write-Verbose -Message "$(Get-Date) $cmd"
    $data=Invoke-Expression $cmd
}
Catch 
{
    Write-Warning "Failed to retrieve namespace information from $Computername"
    Write-Error $_
}

if ($data)
{
  Write-Verbose "$(Get-Date) Processing $(($data | measure-object).count) items"
  
  if ($Recurse) {
      #format the data to accomodate nested namespaces
      $data | Sort __NAMESPACE | Select @{Name="Computername";Expression={$_.__SERVER}},
      @{Name="Namespace";Expression={$_.__NAMESPACE}},
      @{Name="Name";Expression={Split-Path $_.__Namespace -Leaf }}
  }
  else {
       $data | Sort __NAMESPACE | Select @{Name="Computername";Expression={$_.__SERVER}},
      @{Name="Namespace";Expression={Join-path -Path $_.__NAMESPACE -ChildPath $_.Name }},Name
  }
}

 } #close process

End {
    Write-Verbose -Message "$(Get-Date) Ending $($myinvocation.mycommand)"
 } #close End

} #end Function