title: Commenting out a set of lines in a shell script
body: <p>I was wondering if there is a way to comment out a set of lines in a shell script.
  How could I do that? We can use /* */ in other programming languages.
  This is most useful when I am converting/using/modifying another script 
  and I want to keep the original lines instead of deleting.</p>
  
  <p>It seems a cumbersome job to find and prefix # for all the lines which are not used.</p>
  
  <p>Lets say there are 100 lines in the script in consequent lines which are not to used.
  I want to comment them all out in one go. Is that possible?</p>