#!/usr/bin/env bash

echo -n "Are you sure (Y/N)? "

answered=
while [[ ! $answered ]]; do
  #statements
  read -r -n 1 -s answer
  if [[ $answer = [Yy] ]]; then
    #statements
    answered="yes"
  elif [[ $answer = [Nn] ]]; then
    #statements
    answered="no"
  else
    answered="Fail"
  fi
done

printf "\n%s\n" $answered