How to find which Cmdlet Alias was used by user?

Please excuse me if you find this a very lame questions, but since I am learning Powershell I need to ask. This is a sort of next part of the question posted and answer received here. I have a custom cmdlet named Get-DirectoryListing and I added an alias 'gdl' (using New-Alias command in .psm1 file). So user can use either Get-DirectoryListing or gdl to fire the same command. Now I want to detect in my code (.NET, C#) which text was used to execute the command. Lets say if user used alias 'gdl' to execute the command, I want to show message like 'This alias is deprecated and shouldn't be used.' But I do not want to show this message if user uses Get-DirectoryListing to execute the command. What is the best way to achieve this?