title: GNU parallel output progress while output to file
body: <p>I have a simple bash script to run:</p>
  
  <pre><code>cat full_path.csv | parallel --progress -j +0 'echo -n {},; pdfgrep -c [^_] {};' &gt; path_count.csv
  </code></pre>
  
  <p>Parallel's progress indicator <code>"--progress"</code>, writes into the file <code>path_count.csv</code>. I only want <code>echo {}</code> and <code>pdfgrep {}</code> to write to the file, while showing <code>--progress</code> output to screen.</p>
  
  <p>If I do : </p>
  
  <pre><code>cat full_path.csv | parallel --progress -j +0  'echo -n {},&gt;&gt;path_count.csv; pdfgrep -c [^_] {}&gt;&gt;path_count.csv;'
  </code></pre>
  
  <p>the file path_count is still garbled with progress.</p>
  
  <p>Any help is appreciated. Thanks
  Alvin</p>