Fedora 18

[Roger]

I think my Fedora 18 uses nautilus for file management, but it may be 
nemo, I've never taken any notice.

I'm wondering if I can set a default somewhere so that when opening ruby 
.rb and .erb  rails files in my Rails development directory it will 
default to using Geany instead of GEdit.
Is there somewhere to set these default please
I have looked in .config/geany  /nautilus  /nemo  and .local with no luck.

Thanks in advance
Roger