title: Bash script help with if then else and case sensitivity
body: <p>Ok I'm trying to have a situation where I check if a file exists, if it does then I give the user the option to download it again - I want the default (enter) to be Y, I want Y or y to continue the script, I want N or n to exit the script, and I want all other responses to go back and re-prompt the question... but I'm stuck on that. </p>
  
  <p>What I've done really just continues on (enter), and fails on all other responses other than lowercase y. </p>
  
  <p>Here it is:</p>
  
  <pre><code>if [ -f $target/$remote_backup ];then
      read -p "This file already exists, do you still want to download? [Y/n]" decide
       if [ -z $decide ];then
          # if you press return it'll default to Y and continue
          decide="Y"
      else
          if [ $decide != y ]; then
          echo "Ok you said no or pressed a random button, exiting"
          exit -1
      fi
  fi
  fi
  </code></pre>