title: sed / awk - remove space in file name
body: <p>I'm trying to remove whitespace in file names and replace them. </p>
  
  <p>Input: </p>
  
  <pre><code>echo "File Name1.xml File Name3 report.xml" | sed 's/[[:space:]]/__/g'
  </code></pre>
  
  <p>However the output </p>
  
  <pre><code>File__Name1.xml__File__Name3__report.xml
  </code></pre>
  
  <p>Desired output </p>
  
  <pre><code>File__Name1.xml File__Name3__report.xml
  </code></pre>