if test -n "$$files"; then \
if test -n "$$prohibit"; then \
grep $$with_grep_options $(_ignore_case) -nE "$$prohibit" $$files \
- | grep -vE "$${exclude-^$$}" \
+ | grep -vE "$${exclude:-^$$}" \
&& { msg="$$halt" $(_sc_say_and_exit) } || :; \
else \
grep $$with_grep_options $(_ignore_case) -LE "$$require" $$files \