You can use the read command. Here's an example:
while true; do
read -p "Do you wish to install this program?" yn
case $yn in
[Yy]* ) make install; break;;
[Nn]* ) exit;;
* ) echo "Please answer yes or no.";;
esac
done
Another way you can use it is by using Bash select command. example:
echo "Do you wish to install this program?"
select yn in "Yes" "No"; do
case $yn in
Yes ) make install; break;;
No ) exit;;
esac
done
If you choose select you won't have to sanitize the input i.e. it will display the choices and you'll have to type a number matching your choice.