title: Merge multiple XML files from command line
body: <p>I have several xml files. They all have the same structure, but were splitted due to file size. So, let's say I have <code>A.xml</code>, <code>B.xml</code>, <code>C.xml</code> and <code>D.xml</code> and want to combine/merge them to <code>combined.xml</code>, using a command line tool.</p>
  
  <p>A.xml</p>
  
  <pre><code>&lt;products&gt;
      &lt;product id="1234"&gt;&lt;/product&gt;
      ...
  &lt;/products&gt;
  </code></pre>
  
  <p>B.xml</p>
  
  <pre><code>&lt;products&gt;
    &lt;product id="5678"&gt;&lt;/product&gt;
    ...
  &lt;/products&gt;
  </code></pre>
  
  <p>etc.</p>