Vim: clean up hidden buffers

hiddenBuffersLimit.vim

" Clean up hidden buffers
command! -bar -bang -nargs=? CleanBuffers call CleanBuffers("<bang>")

function! CleanBuffers(...) abort
  let force = a:0 >= 1 && a:1 ==# '!'
  redir => bufs
    silent! buffers
  redir END

  let hidden = []
  for buf in map(split(bufs, '\n'), 'split(v:val)')
    let bufnr = buf[0] + 0
    let flags = matchstr(join(buf[1:]), '^.*\ze\s\+"')
    let mod = substitute(flags, '\s*', '', 'g')
    let hide = mod ==# 'h' || mod ==# 'h+'
        \ && (force || input(printf("\n%s not saved.\nDelete anyway? [Y]es, (N)o: ",
          \ bufname(bufnr))) =~? '^y\%[es]$')
    if hide
      call add(hidden, bufnr)
    endif
  endfor

  let saved = get(g:, 'bufcleaner_max_save', 2)
  let target = len(hidden) > saved ? join(hidden[0:-saved-1], ' ') : ''
  if !empty(target)
    silent! execute 'bwipeout!' target
  endif
endfunction