title: How to make tail display only the lines that have a specific text?
body: <p>How to make <strong>tail</strong> display only the lines that have a specific text? If the search criteria can be a regular expression, it would be even better. I need something like:</p>
  
  <pre><code>tail -f mylogfile.log showOnlyLinesWith "error: "
  </code></pre>
  
  <p>I am running Darwin (Mac OS X) and I'm totally beginner in the bash.</p>