title: how to use regexp to match a parentheses in TCL
body: <p>I have a question about using regexp to match a parentheses in TCL.</p>
  
  <p>For example I have a string like this:</p>
  
  <pre><code>yes, it is (true, and it is fine).
  </code></pre>
  
  <p>I just want to match this part <code>yes, it is (true</code>, how to match it?</p>