什么是vimrc函数来确定缓冲区是否已被修改？

例如,当我打开vim -p file * .txt时,这是我的tabline

file1.txt file2.txt file3.txt

然后在我更改file1.txt后不保存它：

*file1.txt file2.txt file3.txt

我的tabline函数：

if exists("+showtabline")
   function MyTabLine()
      let s = ''
      let t = tabpagenr()
      let i = 1
      while i <= tabpagenr('$')
         let buflist = tabpagebuflist(i)
         let winnr = tabpagewinnr(i)
         let s .= ' %*'
         let s .= (i == t ? '%#TabLineSel#' : '%#TabLine#')
         let file = bufname(buflist[winnr - 1])
         let file = fnamemodify(file,':p:t')
         if file == ''
            let file = '[No Name]'
         endif
         let s .= file
         let i = i + 1
      endwhile
      let s .= '%T%#TabLineFill#%='
      let s .= (tabpagenr('$') > 1 ? '%999XX' : 'X')
      return s
   endfunction
   set stal=2
   set tabline=%!MyTabLine()
endif