title: How to grep for case insensitive string in a file?
body: <p>I have a file <code>file1</code> which ends with
  <code>Success...</code> OR
  <code>success...</code></p>
  
  <p>I want to <code>grep</code> for the word <code>success</code> in a way which is not case sensitive way.</p>
  
  <p>I have written the following command but it is case sensitive</p>
  
  <p><code>cat file1 | grep "success\.\.\."</code></p>
  
  <p>How can i change it so that it <code>returns 0</code> with both <code>Success...</code> OR
  <code>success...</code></p>