Recursively get distribution list members

Question

Hi,
I've been asked to supply the membership of several of our large distribution lists.  However, these lists are heavily nested, so I need to get membership recursively starting from the top level list.  The old ONDL.EXE utility could do this.  I was wondering if there was a powershell command that could accomplish the same thing.  The get-distributiongroupmember cmdlet does not seem to have recursive abilities.  If not, could someone help me with a script to do this?
Thanks,
Don

Answer 1

This is kind of long, but works:
(watch line wraps)
Save it as something like get-exgrouprecurse.ps1, and call it like this:
$members  = get-exgrouprecurse <group name>
Then, $members will contain all the members full objects, and the group name they are actually in
Code Snippet
# Script to retreive group members #
# Karl Mitschke March 7 2008 #
# heavily modified from recipe 7.3 #
# in 'Active Directory Cookbook' #
# by Robbie Allen #
#requires -pssnapin Microsoft.Exchange.Management.PowerShell.Admin
param($group)
$UnknownGroup = @{}
function DisplayMembers($group)
$SubGroup = @{}
$AllMembers = @()
if(!$group)
$group = Read-Host "Enter the groups display name"
if ($group.Contains("'"))
$group = $group.Replace("'",'"')
if ($group -eq "/?")
Write-Host "Usage:"
Write-Host ""
Write-Host "get-exgrouprecurse -group <group name>"
Write-Host ""
Write-Host "or get-exgrouprecurse <group name>"
Write-Host "Returns an object containing the group member, and the group name."
break
$validate = Get-Group $group
if ($validate.RecipientTypeDetails.ToString() -match "mail")
$searchGroup = Get-DistributionGroupMember $group
if ($searchGroup)
foreach ($member in $searchGroup)
$membertype = $member.RecipientTypeDetails
if($membertype -match "Group")
$samname = $member.SamAccountName.ToString()
if ($SubGroup.ContainsKey($samname) -eq $true)
Write-Output "^ already seen group member (stopping to avoid loop)"
else
$SubGroup.Add($samname,$member.DisplayName.ToString())
else
if($member.PrimarySmtpAddress -and $member.RecipientTypeDetails -notcontains "group")
$obj = new-object psObject
$obj | Add-Member -membertype noteproperty -name GroupMember -Value $member
$obj | Add-Member -MemberType noteproperty -Name GroupName -Value $group
$AllMembers += $obj
else
$UnknownGroup.add($group,1)
if($SubGroup.Values.Count -gt 0)
foreach ($subGroup in $SubGroup.values)
DisplayMembers $subGroup
if ($UnknownGroup.Keys.Count -gt 0)
foreach ($LostGroup in $UnknownGroup.keys)
$obj = new-object psObject
$obj | Add-Member -membertype noteproperty -name GroupMember -Value "Cannot enumerate group"
$obj | Add-Member -MemberType noteproperty -Name GroupName -Value $LostGroup
$AllMembers += $obj
$UnknownGroup.Clear()
else
Write-Output "$group does not appear to be mail enabled."
Write-Output $AllMembers
DisplayMembers $group