display git branch on statusline.

.vimrc

autocmd WinEnter,BufEnter * let b:__gitbranchname = system('cd ' . expand('%:p:h') . ' && git symbolic-ref HEAD 2> /dev/null')

"文字コード改行コードの取得
function! GetStatusEx()
        let str = ''
        let str = str . '[\n:' . &fileformat . ']'
        if has('multi_byte') && &fileencoding != ''
                let str = str . '[enc:' . &fileencoding . ']'
        else
                let str = str . '[enc:default(cp932)]'
        endif
        if b:__gitbranchname != ''
          let str = str . '[git:' . substitute(b:__gitbranchname, '\n', '', '') . ']'
        endif
        return str
endfunction

"ステータスバーの表示
set statusline=%<%f%h%m%r\ %{GetStatusEx()}%=%b\ 0x%B\ \ \ %l,%c%V\ %P