title: AWK: shortened if-then-else with regex
body: <p>The following AWK format:</p>
  
  <pre><code>/REGEX/ {Action}
  </code></pre>
  
  <p>Will execute <code>Action</code> if the current line matches <code>REGEX</code>.</p>
  
  <p>Is there a way to add an <code>else</code> clause, which will be executed if the current line does not matches the regex, without using if-then-else explicitly, something like:</p>
  
  <pre><code>/REGEX/ {Action-if-matches} {Action-if-does-not-match}
  </code></pre>