title: character case conversion Uppercase to Lower and vice versa
body: <p>I was trying to convert the lowercase characters to uppercase. I came across various alternatives like one listing at the StackOverflow <a href="https://stackoverflow.com/questions/2264428/converting-string-to-lower-case-in-bash-shell-scripting">question</a>. However, What i saw that these are just printed. I want to save it to another variable which i can use later.
  Can anyone tell how i can achieve this?</p>