test:
echo $(shell pwd)
echo $(shell false)
echo $(shell /bin/echo -e "\na \n b \n " )
echo $(shell /bin/echo -e "\na \n b \n " )X
echo X$(shell /bin/echo -e "\n\n" )Y
echo X$(shell /bin/echo -e "a\n\n" )Y
echo X$(shell /bin/echo -e "\n\nb" )Y
echo X$(shell /bin/echo -e "\n\nb" )Y
echo X$(shell /bin/echo -e "\n\n\nb" )Y
echo X$(shell /bin/echo -e " b" )Y
echo X$(shell /bin/echo -e "b " )Y