Powershell Get-LocalGroupMember adds computer name to $._Name so it cannot be compared to txt file-CodePudding

Essentially, my script is supposed to check if each user in the administrators group is listed inside of a text file, and if it is then ignore it and move on. If it isn't, it removes the user from the administrator group. However, Get-LocalGroupMember prepends the computer name to the username. This means that the username in the txt file (ex user1), does not match the $._Name variable from the Get-LocalGroupMember command (ex desktop/user1). Here is a copy of the code

$GroupName = "Administrators"
$Exclude = "Administrator","$env:UserName"
$AuthorizedAdmins = Get-Content C:\Users\$env:UserName\admins.txt

Get-LocalGroupMember $GroupName |
    ForEach-Object{
        if ($_.ObjectClass -eq 'User'){
        if ($AuthorizedAdmins -contains $_.Name -or $Exclude -contains $_.Name){
            Continue
        }
        else{
            Remove-LocalGroupMember -Group $GroupName -Member $_.Name -Confirm
        }
    }
}

I have tried several solutions. In the code, I created a new variable that removed the first $env:ComputerName 1 characters of the $._Name string. While this did work to remove the computername, powershell errors out. Here is the error code and changed script:

Get-LocalGroupMember : System error.
At users.ps1:6 char:1
  Get-LocalGroupMember $GroupName |
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      CategoryInfo          : NotSpecified: (:) [Get-LocalGroupMember], ContinueException
      FullyQualifiedErrorId : An unspecified error occurred.,Microsoft.PowerShell.Commands.GetLocalGroupMemberCommand

$GroupName = "Administrators"
$Exclude = "Administrator","$env:UserName"
$AuthorizedAdmins = Get-Content C:\Users\$env:UserName\admins.txt
   
Get-LocalGroupMember $GroupName |
    ForEach-Object{
        $User = $_.Name
        $length = $env:ComputerName.Length 1
        $ShortUser = $User.Remove(0,$length)
        if ($_.ObjectClass -eq 'User'){ #ignore groups and select only users
            if ($AuthorizedAdmins -contains $ShortUser -or $Exclude -contains $ShortUser){
                Continue
            }
            else{
                Remove-LocalGroupMember -Group $GroupName -Member $_.Name -Confirm
            }
        }
    }

The admin.txt file is formatted as follows:

user1
user2
user3

I cannot figure out how to fix this, though it is probably someting simple. Any help would be appreciated.

CodePudding user response：

The real issue with your code is your use of continue in a ForEach-Object loop, see note from the docs. If you want to emulate continue in a pipeline processing function you should use return instead. So your code, with some improvements and simplifications would be:

$GroupName = "Administrators"
$exclude = @(
    "Administrator"
    $env:UserName
    Get-Content C:\Users\$env:UserName\admins.txt
)

Get-LocalGroupMember $GroupName | ForEach-Object{
    # if its not a user, skip this logic
    if ($_.ObjectClass -ne 'User') {
        return
    }
    # here we assume its a user
    if ($_.Name.Split('\')[-1] -in $exclude) {
        return
    }
    
    Remove-LocalGroupMember -Group $GroupName -Member $_.Name -Confirm
}