[plug] Is there a way to tell whats in a swapfile?

[W.Kenworthy]

Is there a way to tell whats in a swapfile?  I currently have 1.4+ G and
would like to see what apps are actually present in there.

The gnome system monitors shows X with over 400M, firefox > 600M, and
quite a number with >200M as there footprint in memory, but other apps
(obviously using different criteria such as showing RAM resident size
only) such as top dispute this.

BillK