Creating a PowerShell script that can install itself as module

Powershell advanced functions are a lightweight, yet pretty powerful way to extend the set of commands available in a Powershell sessions. Advanced functions look and feel almost exactly like proper cmdlets, but they are written in Powershell and therefore quick to develop.

By default, advanced functions are ephemeral though: If you run a script containing an advanced function, that function is going to be available for the rest of the Powershell session – after that, it is gone. To make an advanced function available permanently – like a cmdlet – you have to wrap it in a Powershell module, and install that module.