title: Move files with new filenames
body: <p>I have files</p>
  
  <pre><code>/folder/file1.mp4
  /folder/file2.wmv
  /folder/file3.mov
  </code></pre>
  
  <p>I need to move them to new folder with new filename, which randomly generated from 12 symbols.</p>
  
  <pre><code>/new-folder/345457567452.mp4
  /new-folder/890897687685.wmv
  /new-folder/235344783456.mov
  </code></pre>
  
  <p>How can I do it?</p>
  
  <p>The problem is: I don't know extesion of original file, and I need rename only name of ile and save extension.</p>