title: How to find lines including two letter words using grep
body: <p>I'd like to find lines that include two character words in a text file.</p>
  
  <p>I've tried:   </p>
  
  <pre><code>grep '..' file.txt
  grep '[..]' file.txt
  grep -w '..' file.txt
  grep -w '[..]' file.txt
  egrep '(\b^[.]|[.]$)' file.txt
  egrep '(\b^[.]|[.]$|[..])' file.txt
  egrep '..|[..]' file.txt
  </code></pre>
  
  <p>but it does not catch all the lines needed.</p>
  
  <p>Any ideas?</p>