You can run script from both links using powercli
I have tried script from first link and it worked.
C:\WINDOWS\system32\windowspowershell\v1.0 powershell.exe -PSConsoleFile "C:\Program Files\VMware\Infrastructure\vSphere PowerCLI\vmMac.ps1" -command "connect-viserver -server <myVCenter> -user <myUser> -password <myPassword>
$strMacToFind = "00:50:56:83:00:69"
## return the .NET View object(s) for the VM(s) with the NIC w/ the given MAC
Get-View -Viewtype VirtualMachine -Property Name, Config.Hardware.Device | ?{$_.Config.Hardware.Device | ?{($_ -is [VMware.Vim.VirtualEthernetCard]) -and ($_.MacAddress -eq $strMacToFind)}}