bind-key y {
    capture-pane -J
    save-buffer /tmp/tmux-buffer
    delete-buffer
    split-window 'vim -c "set listchars=" -c "match ExtraWhitespace //" /tmp/tmux-buffer'
}

bind-key Y {
    capture-pane -J -S - -E -
    save-buffer /tmp/tmux-buffer
    delete-buffer
    split-window 'vim -c "set listchars=" -c "match ExtraWhitespace //" /tmp/tmux-buffer'
}