Get User by loginname using powershell

Question

We have the following script that was running on sharepoint 2010 where we had clasic windows authentication.

When we moved to SP 2013, the authentication was changed to Claims.

The following code doesnt work anymore on Sp 2013

$spsite = new-object Microsoft.SharePoint.SPSite("https://mysite.com/");
$web = $spsite.openweb("/subsite1/subsite2/")
$removeUser = $web.AllUsers["domainname\username"];

I have to add the claims thing to make it work

$spsite = new-object Microsoft.SharePoint.SPSite("https://mysite.com/");
$web = $spsite.openweb("/subsite1/subsite2/")
$removeUser = $web.AllUsers["i:0#.w|domainname\username"];

How can I change this to make it work without the claim thingy!

Answer 1

Try this variant, replacing the AllUsers lookup with EnsureUser

$spsite = new-object Microsoft.SharePoint.SPSite("https://mysite.com/")
$web = $spsite.openweb("/subsite1/subsite2/")
$removeUser = $web.EnsureUser("domainname\username")

Or, if you do not wish to add the user to the site even to then delete him/ her, you can build on this functionality (could probably be improved a great bit):

$loginName = "domainname\username"
$users = Get-SPUser -Web $web.Url

foreach($user in $users)
{
    if($user.LoginName.Contains($loginName))
    {
         $removeUser = $user
         break
    }
}

Or, as this guy has done, implement a supporting method:

$m = [Microsoft.SharePoint.Administration.Claims.SPClaimProviderManager]::Local
Add-PSSnapin Microsoft.SharePoint.PowerShell -ea silentlycontinue 
Function Get-SPClaim {
    param ([string]$user)
    $claim = New-SPClaimsPrincipal -identity $user -IdentityType "WindowsSamAccountName"
    return $m.EncodeClaim($claim)
}

that you can use like:

$userWithClaim = get-SPClaim($loginName)
$removeUser = $web.AllUsers[$userWithClaim]