title: regex string between two strings
body: <p>How can I get the text between two constant text?</p>
  
  <p>Example:</p>
  
  <pre><code>&lt;rate curr="KRW" unit="100"&gt;19,94&lt;/rate&gt;
  </code></pre>
  
  <p><strong>19,94</strong></p>
  
  <p>is between</p>
  
  <pre><code>"&lt;rate curr="KRW" unit="100"&gt;"
  </code></pre>
  
  <p>and</p>
  
  <pre><code>"&lt;/rate&gt;"
  </code></pre>
  
  <hr>
  
  <p>Other example:</p>
  
  <pre><code>ABCDEF
  </code></pre>
  
  <p>getting substring between
  <code>AB</code> and <code>EF</code>= <code>CD</code></p>