title: Find and replace filename recursively in a directory
body: <p>I want to rename all the files in a folder which starts with <code>123_xxx.txt</code> to <code>xxx.txt</code>.</p>
  <p>For example, my directory has:</p>
  <pre><code>123_xxx.txt
  123_yyy.txt
  123_zzz.txt
  </code></pre>
  <p>I want to rename all files as:</p>
  <pre><code>xxx.txt
  yyy.txt
  zzz.txt
  </code></pre>
  <p>I have seen some useful bash scripts in this forum but I'm still confused how to use it for my requirement.</p>
  <p>Let us suppose I use:</p>
  <pre><code>for file in `find -name '123_*.txt'` ; do mv $file {?.txt} ; done
  </code></pre>
  <p>Is this the correct way to do it?</p>