title: How to extract .tar.gz file in ubuntu
body: <p>I want to extract an archive named <code>kdiff3.tar.gz</code>.</p>
  
  <p>Using <code>tar -xzvf kdiff3.tar.gz</code>, doesn't extract the file. It gives this error:</p>
  
  <pre><code>   gzip: stdin: not in gzip format
     tar: Child returned status 1
     tar: Error exit delayed from previous errors
  </code></pre>
  
  <p>Using <code>file kdiff3.tar.gz</code> gives this message:</p>
  
  <pre><code>   kdiff3.tar.gz: HTML document, ASCII text
  </code></pre>
  
  <p>It would be great, if someone could help.</p>