$PS4 is for sh -x. Well, $PS5 or $PSv should be for sh -v! Imagine, with just a simple PS5='$ ', one could produce perfect dialogues,
$ set -eu /tmp/x $ mkdir $@ $ cd $@ $ seq 3|xargs touch $ ls -U $@ 3 2 1 $ mv -v $@ /var$@ created directory '/var/tmp/x' copied '/tmp/x/1' -> '/var/tmp/x/1' copied '/tmp/x/2' -> '/var/tmp/x/2' copied '/tmp/x/3' -> '/var/tmp/x/3' removed '/tmp/x/3' removed '/tmp/x/2' removed '/tmp/x/1' removed directory '/tmp/x' $ ls -U /var$@ 3 1 2 $ rm -vr /var$@ removed '/var/tmp/x/3' removed '/var/tmp/x/1' removed '/var/tmp/x/2' removed directory '/var/tmp/x' all ready for the classroom, or textbook publisher, instead of just a jumbled set -eu /tmp/x mkdir $@ cd $@ seq 3|xargs touch ls -U $@ 3 2 1 mv -v $@ /var$@ created directory '/var/tmp/x' copied '/tmp/x/1' -> '/var/tmp/x/1' copied '/tmp/x/2' -> '/var/tmp/x/2' copied '/tmp/x/3' -> '/var/tmp/x/3' removed '/tmp/x/3' removed '/tmp/x/2' removed '/tmp/x/1' removed directory '/tmp/x' ls -U /var$@ 3 1 2 rm -vr /var$@ removed '/var/tmp/x/3' removed '/var/tmp/x/1' removed '/var/tmp/x/2' removed directory '/var/tmp/x' when using this script, PS5='$ ' set -v set -eu /tmp/x mkdir $@ cd $@ seq 3|xargs touch ls -U $@ mv -v $@ /var$@ ls -U /var$@ rm -vr /var$@ In fact $PS5 could even be dynamically expanded just like some other $PS's.
