emerge ?AGAIN? after defining USE variable? (Solved)

[podollb]

Hi,
I was wondering if I had to 'emerge' applications again if I have changed my USE variable setting? For instance, I have installed several packages prior to updating my USE variable and want to know if the emerge world trick will pick up the changes and update the packages or if I just need to emerge all of them again?

[msalerno]

This is all over the forums, just do a search.

You could try man emerge

or you could simply

emerge -Np world