Hi,

I am trying to align a dzen2 bar to the right of my screen.
A dzen2 bar is aligned by giving an offset from the left side of the screen.
Since I have a single xmonad.hs for multiple computers, I would like to retrieve the width of the screen from XMonad.
I found the following snippet online:
main = do
(_, out, _, process_handle) <- runInteractiveCommand "echo WIDTH | eval m4 `xrdb -symbols`"
...
This does not seem really satisfactory.
I know this information is available from inside XMonad, probably in a ScreenDetail from XMonad.Core.

My question is: "How can I retrieve this number from XMonad?"

Another way look at that the question is: "What is the best way to figure out things in XMonad?"
I have a specific question, found a potential candidate in the documentation, and would like to experiment before changing my xmonad.hs.
Is there a way to use ghci to look around?

Thanks.