tmux same file twice

set noswapfile         " Write swap and backup files

set noautoread         " together with :checktime (and set confirm), prompt to reload file
set confirm            " get a dialog when :q, :w, or :wq fails


" Detect file modified elsewhere {{{
" forgot where i got it from :(
augroup AutoSwap
    autocmd!
    autocmd SwapExists *  call AS_HandleSwapfile(expand('<afile>:p'), v:swapname)
augroup END

function! AS_HandleSwapfile (filename, swapname)
    " if swapfile is older than file itself, just get rid of it
    if getftime(v:swapname) < getftime(a:filename)
        call delete(v:swapname)
        let v:swapchoice = 'e'
    endif
endfunction
autocmd BufWritePost,BufReadPost,BufLeave *
            \ if isdirectory(expand("<amatch>:h")) | let &swapfile = &modified | endif

augroup checktime
    autocmd!
    if !has("gui_running")
        "silent! necessary otherwise throws errors when using command
        "line window.
        autocmd BufEnter,CursorMoved,CursorMovedI * checktime
        autocmd FocusGained,BufEnter,FocusLost,WinLeave * checktime
    endif
augroup END