display information in seperate buffer

[Fabian Braennstroem]

Hi,

I wonder if there exist any package that filters out some
information about certain files using dired and display
those in a separate buffer.
I mean I would like to extract lines with certain keywords
(e.g. fluid and turbulence) or special lines from the file
which is currently 'active' in dired. It is probably similar
to some mbox filtering. And more advanced: if two files are
'active/marked' then show the infos in separate windows and
highlight the differences (probably like ediff-buffers).

Greetings, Fabian