Functions/Public/Get-LocalAdmin.ps1

#!/usr/bin/env pwsh

<#
.SYNOPSIS
    Retrieves a list of users in the local Administrators group.
 
.DESCRIPTION
    This function identifies local admins from the computer or server it is run from.
 
.EXAMPLE
    PS> Get-LocalAdmin
 
    Description
    -----------
    Generates a list of local admins
 
.EXAMPLE
    PS> Get-LocalAdmin -ComputerName SomeRemoteComputer-PC
 
    Description
    -----------
    Generate a list of local admins on a remote PC.
 
.NOTES
    Author: Matthew J. DeGarmo
    GitHub: https://github.com/matthewjdegarmo
#>

#Requires -Assembly C:\Windows\system32\net.exe
function Get-LocalAdmin() {
    [CmdletBinding()]
    param(
        [Parameter()]
        [string] $ComputerName = $env:COMPUTERNAME
    )

    if ($PSBoundParameters.ContainsKey('ComputerName')) {
        $NetAdminObject = Invoke-Command -ComputerName $ComputerName -ScriptBlock { (net.exe localgroup Administrators) -split '\r?\n' }
    }
    else {
        $NetAdminObject = (net.exe localgroup Administrators) -split '\r?\n'
    }
    $NetAdminObject[6..(($NetAdminObject.count) - 3)]
}