zsh can be used as sh instead of bash for almost everything. I have two machines here where /bin/sh is a link to /bin/zsh. This makes apsfilter work. bash gives an error in a pipe, complaining about some signal. It's a bash bug; with zsh it works. The only problem is that some packages, such as gzip, give an error in the perl (!!??) postinst script. I don't know why. Perhaps the zsh maintainer could investigate this? Carlos