title: recompress .gz file without unzipping to a temp file first
body: <p>I have test.gz file that I wish to recompress(using better compression ratio):
  <pre></p>
  
  <code>  gunzip test.gz
    gzip -8 test
  </code></pre>
  
  <p></p>
  
  <p>can this be done?</p>