Powershell iterate through collection in where-object - powershell

Question

Forgive me in advance as I may not be defining things correctly here:
I have a script that queries Active Directory for users in a specific OU while excluding a dozen or so OUs within that OU. The script works, but it's kind of messy as I'm declaring 13 variables representing the various OUs and referencing them in where-object. There's also an existing foreach loop as I'm querying more than one domain. I'd like to find a way to reference all the OU's I'm excluding from the query in a single collection or array or whatever and loop through it in my where-object to avoid having to reference 13 variables in the where-object. Can anyone point me in the right direction? (Code below excludes the OU variable defintions)
Existing Code:
(Get-ADForest).domains | foreach {
Get-ADUser -filter {Enabled -eq $True} -properties * -SearchBase "OU=Accounts,$((Get-ADDomain -Server $_).DistinguishedName)" -Server $_ |
where-object {$_.Title -notmatch "Volunteer" -and $_.DistinguishedName -notmatch $excludeOU1 -and $_.DistinguishedName -notmatch $excludeOU1 -and $_.DistinguishedName -notmatch $excludeOU2 -and
$_.DistinguishedName -notmatch $excludeOU3 -and $_.DistinguishedName -notmatch $excludeOU4 -and $_.DistinguishedName -notmatch $excludeOU5 -and $_.DistinguishedName -notmatch $excludeOU6 -and
$_.DistinguishedName -notmatch $excludeOU7 -and $_.DistinguishedName -notmatch $excludeOU8 -and $_.DistinguishedName -notmatch $excludeOU9 -and $_.DistinguishedName -notmatch $excludeOU10 -and
$_.DistinguishedName -notmatch $excludeOU11 -and $_.DistinguishedName -notmatch $excludeOU12 -and $_.DistinguishedName -notmatch $excludeOU13 }
}
Thanks!

Answer 1

You could use a regex to use with notmatch.
[regex]$excluderegex = "^(excludeOU1|excludeOU2|excludeOU3)$"
(Get-ADForest).domains | foreach {
Get-ADUser -filter {Enabled -eq $True} -properties * -SearchBase "OU=Accounts,$((Get-ADDomain -Server $_).DistinguishedName)" -Server $_ |
where-object {$_.Title -notmatch "Volunteer" -and $_.DistinguishedName -notmatch $excluderegex}
}

Answer 2

You can put anything you like inside the Where filter expression:
$excludes = $excludeOU1,$excludeOU2,$excludeOU3,$excludeOU4,$excludeOU5,$excludeOU6,$excludeOU7,$excludeOU8,$excludeOU9,$excludeOU10,$excludeOU11,$excludeOU12,$excludeOU13
Get-ADUser -Filter {Enabled -eq $true} -Properties * -SearchBase "OU=Accounts,$((Get-ADDomain -Server $_).DistinguishedName)" -Server $_ | Where-Object {
$_.Title -notmatch 'Volunteer' -and $(&{
foreach($exclude in $excludes)
{
if($_.DistinguishedName -match $exclude)
{
return $false
}
}
return $true
})
}

Answer 3

You could use the Select-Object cmdlet in your pipeline to add a new "calculated property" to your Get-ADUser data that holds just the OU of the user. The Where-Object call could then simply use a -notin operator.
In my opinion, this would make the code a little more readable. More info here:
Select-Object Calculated Properties
Notin Operator