Use Powershell to check whether and AD user exists

Question

We're trying to clean up roaming profile folders, and as part of the task I need to check whether the user actually exists in AD.  I have tried 3 different methods and so far none of them work.
Either the empty result of the search doesn't equal $null (e.g. If ($objUser -eq $null) resolves to false) or Powershell crashes (like when I try to run that If statement).  So is there an AD User equivalent to Test-Path?
RF

Answer 1

I should add, if you want to use PowerShell filter syntax, you can use:
$Name
= "jsmith"
$User = Get-ADUser
-Filter {sAMAccountName
-eq $Name}
If ($User
-eq $Null) {"User does not exist in AD"}
Else {"User found in AD"}
And if you only have PowerShell V1, you can use the following:
$Name =
"jsmith"
$Searcher =
[ADSISearcher]"(sAMAccountName=$Name)"
$Results =
$Searcher.FindOne()
If ($Results
-eq $Null) {"Users does not exist in AD"}
Else {"User found in AD"}
In all cases I assume you are checking the "pre-Windows 2000 logon" name, not the Common Name (the value of the cn attribute, which does not uniquely identify the object in AD).
Richard Mueller - MVP Directory Services