title: tail pipe grep pipe xmllint not working
body: <p>I'm trying to get the below command working but no o/p is getting printed:</p>
  
  <pre class="lang-bsh prettyprint-override"><code>tail -f mylog.log | grep --line-buffered -Eo '&lt;S:Envelope .+Envelope&gt;' | xmllint --format --recover -
  </code></pre>
  
  <p>However, if I grep the same pattern from a file, and pipe it to xmllint, it works:</p>
  
  <pre class="lang-bsh prettyprint-override"><code>grep --line-buffered -Eo '&lt;S:Envelope .+Envelope&gt;' tmp.xml | xmllint --format --recover -
  </code></pre>
  
  <p>What am I missing in the first command?</p>