Fwiw, here's what I am seeing (on FreeBSD -current using zsh 4.3.12):

lizzy:~% % PS1='%# %(#,$,%%) '
% %
% %
% % sudo -s
lizzy:/home/jos# PS1='%# %(#,$,%%) '
# $
# $

On Tue, Dec 6, 2011 at 9:03 PM, Daniel Lin <dlin.tw@gmail.com> wrote:

> PS1='%# %(#,$,%%)'



-- 
Jos Backus
jos at catnook.com