Add template that prompts a user for input until a valid answer is
provided.
--- /dev/null
+#!/bin/bash
+
+# Desc: Prompts user until valid answer given.
+
+while ! [ "$prompt_status" = "answered" ]; do
+    echo "Perform action? (y/n):" 1>&2;
+    read prompt;
+    case "$prompt" in
+       "y" | "yes")
+           echo -e "Doing stuff.";
+           prompt_status="answered";
+           ;;
+       "n" | "no")
+           echo "Doing nothing.";
+           prompt_status="answered";
+           ;;
+       *)
+           echo "WARNING:Invalid option $prompt"
+           prompt_status="";
+           ;;
+    esac
+done