Apache and viewing C files

[Ferguson, Neale]

How do I configure Apache so that if I click on a hyperlink that corresponds
to some C source code (or any other language or header file), instead of
just getting the raw output produced I get a marked up version? That is, one
that has line numbers down the side? For an example of what I mean see:
"http://lxr.linux.no/source/drivers/s390/char/tuball.c#L280";. (In fact,
while you're there check out the LXR package by playing with
"http://lxr.linux.no";.)