Automatically save and remove trailing whitespace for vim

autosave.vim

" Declare ignore filetype here
let g:ignore_autosave = 'tex'

function AutoSave()
  if &modifiable == 1 && &readonly == 0
      \ && expand('%') != ''
      \ && &buftype != 'nofile'
    %s/\s\+$//e
    if &filetype != g:ignore_autosave
      update
    endif
  endif
endfunction

autocmd InsertLeave * call AutoSave()
autocmd BufLeave * call AutoSave()
autocmd CursorHold * call AutoSave()