Close all hidden buffers in Vim

close_hidden_buffers.vim

command! CloseHiddenBuffers call s:CloseHiddenBuffers()
function! s:CloseHiddenBuffers()
  let open_buffers = []

  for i in range(tabpagenr('$'))
    call extend(open_buffers, tabpagebuflist(i + 1))
  endfor

  for num in range(1, bufnr("$") + 1)
    if buflisted(num) && index(open_buffers, num) == -1
      exec "bdelete ".num
    endif
  endfor
endfunction