> Sorry, I use sarge, which has bash 2. > > > > > The ls command show once, but pwd show twice. > > > > It seems to me that HISTCONTROL=ignoredups sometime work, sometime > > > > does not work. > > > > It does not work as I have hoped. > > > > > > Probably you need to use HISTCONTROL=erasedups > > > > In bash3 only. I was presume. :) But, sarge have bash3 (3.0-12). You can try.