Dear zsh, I am trying to write a script to be sourced which removes
PATH components matching a given pattern and which is supposed to be
usable from zsh as well as ksh, bash etc. The best I have come up with
so far is the following:

----------cut-here----------------------------------------
oldifs="$IFS"
IFS=:
if [[ $SHELL = *zsh ]]
then
	set ${=PATH}
else
	set $PATH
fi
IFS="$oldifs"
PATH=
for i
do
    case $i in
	    *tetex*)
		    ;;
	    *)
	       PATH=$PATH:$i
	       ;;
    esac
done
PATH=${PATH#:}
----------cut-here----------------------------------------

This works for people who stick with their login shell, but not for
someone who calls ksh from zsh because then SHELL remains set to zsh.
My first try was to test $0 instead of $SHELL, but that gets set to
the name of the file being sourced by zsh (with some option settings).

Does anybody have a better idea either for a reliable test on whether
zsh is running or for a way which avoids the test?

(I know that the above fragment breaks with 10 or more PATH components
- I should use a while loop with shift instead of the for loop).

-- 
Klaus Wacker              wacker@Physik.Uni-Dortmund.DE
Experimentelle Physik V   http://www.physik.uni-dortmund.de/~wacker
Universitaet Dortmund     Tel.: +49 (231) 755 3587
D-44221 Dortmund          Fax:  +49 (231) 755 3569