title: Renaming a set of files in linux
body: <p>I have 100 files named <code>sub1.txt, sub2.txt,..., sub100.txt</code>. I like to rename them as <code>all1.txt, all2.txt,..., all100.txt</code>. How can one do this in linux (unix)?</p>
  
  <p>Thanks for your help.</p>