The file in question being current, use
setlocal fileformat=unix
To do it when opening any .* and *.rb files,
if has('autocmd')
autocommand BufRead,BufNewFile .*,*.rb setlocal ff=unix
endif
The "if" wrapper is there because you of course cannot use autocommands
if the autocommand feature hasn't been compiled-in.
Best regards,
Tony.
--
Coward, n.:
One who in a perilous emergency thinks with his legs.
-- Ambrose Bierce, "The Devil's Dictionary"