title: tcsh: How to change the file extension for multiple files?
body: <p>Is there a one line command in <code>tcsh</code> to change the extension of a set of files?  In the various DOS shells, I used to use the following:</p>
  
  <pre><code>ren *.abc *.def
  </code></pre>
  
  <p>This would rename all files ending in <code>.abc</code> to end instead with <code>.def</code>.  In <code>sed</code> terms this would perform something like the following:</p>
  
  <pre><code>sed -e 's/\(.\)*\.abc$/\1.def/'
  </code></pre>
  
  <p>on the file names.  I could probably throw bits and pieces together to achieve something similar in *nix, but I'm guessing that the issue here is my lack of experience with <code>tcsh</code>.</p>
  
  <p>Any help appreciated.</p>