Simplify/unify listfiles recursion: populate directory node (and detect top of tree) at start of function rather than end (and redundantly in main). Move title printing down next to total printing.

#!/bin/sh
#HELP usage: unix2dos [FILE...]\n\nAdd DOS newlines

[ $# -ne 0 ] && DASH_I=-i
sed $DASH_I -e 's/$/\r/' "$@"