title: Use the Jenkins build log variable ${BUILD_LOG} as a substring in the Post Build Actions
body: <p>I want to expose the Jenkins build log as part of the Post Build Actions.  Ideally, I just want to use some of the log, and I'm thinking that I can do this by using a substring of what is produced from the build log.</p>
  
  <pre><code>${BUILD_LOG, maxLines, escapeHtml}
  </code></pre>
  
  <p>Reference: <a href="https://stackoverflow.com/questions/16089096/how-can-i-take-last-20-lines-from-the-build-log-variable">How can I take last 20 lines from the $BUILD_LOG variable?</a></p>
  
  <p>The reason that I want to use substring over maxlines is because I just want to output some of the log, in this case from <code>ERROR:</code>, and the length is variable.</p>
  
  <p>Any help on this would be much appreciated!</p>