run tmux in all emulated tty and attach to them when exiting the shell

.zshrc

# TMUX                                                                                                                                                                           
if [ -z `tty | grep tty` ] ; then
    if which tmux 2>&1 >/dev/null; then
        # if no session is started, start a new session                                                                                                                          
        test -z ${TMUX} && tmux

        # when quitting tmux, try to attach                                                                                                                                      
        while test -z ${TMUX}; do
            echo "Press enter to attach to other tmux instanse, or anything then enter to just leave"
            read attachto
            if [ -z $attachto ]; then
                tmux attach || break
            else
                break
            fi
        done
    fi;
fi;