: ask a question of the user
echo $@ "(Yes, No)? " '\c'
read answer
while true
do case $answer in
	Y*|y*) return 0;;
	N*|n*) return 1;;
	*) echo "Please answer \'Yes\' or \'No\'";
	   echo $@ "(Yes, No)? " '\c'
	   read answer
    esac

done