title: use awk to extract row records contain specific word
body: <p>Say my input file is tab delimited, how do i identify if $0 contains a word "hello" and it needs to be case insensitive?</p>
  
  <pre><code>here is a hello       whateverColumn2
  nonono nonono         whateverItIs
  here HeLLo again      mockColumn2
  </code></pre>
  
  <p>Thanks a lot!</p>