Putting together an ADSI LDAP query - powershell

Question

I am searching through the active directory for users under a specific organisation unit, that I would like to change using ADSI.
# get all users from the organizational unit
$accounts = Get-ADObject -filter 'objectClass -eq "user"' -SearchBase $dsn
# iterate over user objects
foreach ($account in $accounts) {
# unfortunately we have to use ADSI over the set-aduser cmdlet as we neeed to touch remote desktop attribues
$user = [ADSI]"LDAP://" + ($account.DistinguishedName).ToString()
# get logon name
$SamAccountName = $user.psbase.InvokeGet("SamAccountName")
# Profile Attributes
$user.psbase.InvokeSet("ProfilePath", "")
$user.psbase.InvokeSet("ScriptPath", "DIR\Logon.cmd")
$user.psbase.InvokeSet("HomeDrive", "H:")
$user.psbase.InvokeSet("HomeDirectory", "\\host\users$\${SamAccountName}")
# Remote Desktop Services Attributes
$user.psbase.InvokeSet("TerminalServicesProfilePath", "")
$user.psbase.InvokeSet("TerminalServicesHomeDirectory", "\\host\users$\${SamAccountName}")
$user.psbase.InvokeSet("TerminalServicesHomeDrive", "H:")
# Write attributes back to global catalog
$user.SetInfo()
}
This all works fine, until it comes to the $user = [ADSI]"LDAP://" + ($account.DistinguishedName).ToString() part.
Method invocation failed because [System.DirectoryServices.DirectoryEntry] does not contain a method named 'op_Addition'.
At \\tsclient\D\SourceCode\PowerShell\Set-ADUserAttributes.ps1:37 char:5
+ $user = [ADSI]"LDAP://" + ($account.DistinguishedName).ToString()
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (op_Addition:String) [], RuntimeException
+ FullyQualifiedErrorId : MethodNotFound
Exception calling "InvokeGet" with "1" argument(s): "Unspecified error
"
At \\tsclient\D\SourceCode\PowerShell\Set-ADUserAttributes.ps1:40 char:5
+ $SamAccountName = $user.psbase.InvokeGet("SamAccountName")
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
It seems there is no query getting executed. However, $account.DistinguishedName contains the correct LDAP path (which I have tested manually).
So what am I doing wrong here?.

Answer 1

You're trying to append to an ADSI object by casting "LDAP://" as [ADSI] before you do the append.
Cat your strings first, then do the cast:
$user = [ADSI]("LDAP://" + $account.DistinguishedName)

Answer 2

The casting operation has higher precedence than the concatenation operation, so you need to do the concatenation in a subexpression, either like this:
[adsi]("LDAP://" + $account.DistinguishedName)
or like this:
[adsi]"LDAP://$($account.DistinguishedName)"
The distinguished name is automatically converted to a string here, so you don't need to manually call ToString().