Changing Vim behavior by file type using single `.vimrc` (without ftplugin)

Question

How to change Vim behaviour using single .vimrc file (without ftplugin) in elegant way ?

What do I mean is ... if I run many commends for C/C++ file , e

Answer 1

I'd probably do per-filetype functions to do the setup for me. Shamelessly ripping off @Derek...

function! SetUpLispBuffer()
    set lisp
    set showmatch
    set cpoptions-=m
    set autoindent
endfunction

function! SetUpCBuffer()
    set formatprg=c:\\AStyle\\bin\\AStyle.exe\ -A4Sm0pHUk3s4
    set tw=80
endfunction

if has("autocmd")
    augroup LISP
        au!
        au BufReadPost *.cl call SetUpLispBuffer()
    augroup END
    augroup C
        au!
        autocmd BufNewFile,BufRead *.{cpp,c,h} call SetUpCBuffer
    augroup END
endif

A lot less to change when you want to make changes and much less cut&paste too.