title: Extract url from a string with regex in shell script
body: <p>I need to extract a URL that is wrapped with <code>&lt;strong&gt;</code> tags. It's a simple regular expression, but I don't know how to do that in shell script. Here is example:</p>
  
  <pre><code>line="&lt;strong&gt;http://www.example.com/index.php&lt;/strong&gt;"
  url=$(echo $line | sed -n '/strong&gt;(http:\/\/.+)&lt;\/strong/p')
  </code></pre>
  
  <p>I need "http://www.example.com/index.php" in the <code>$url</code> variable.</p>
  
  <p>Using busybox.</p>