autocmd BufRead,BufNewFile /usr/include/*/*   set filetype=c
autocmd BufRead,BufNewFile *.d   set filetype=c
autocmd BufRead,BufNewFile *.dat set filetype=c
autocmd BufRead,BufNewFile *.i   set filetype=c
autocmd BufRead,BufNewFile *.h.merge*   set filetype=c
autocmd BufRead,BufNewFile *.c.merge*   set filetype=c