title: Add header(copyright) information to existing source files
body: <p>I want to add our company's copyright information to all of our EXISTING source code files. </p>
  
  <p>The project is developed in <code>Eclipse</code>. so, for new files I can modify the settings as suggested <a href="https://stackoverflow.com/questions/4105664/adding-a-standard-comment-header-to-all-source-files-in-eclipse">here</a>. But for existing files, how am I supposed to do this. How can I modify hundreds of java files to add the copyright information. (And I'm unable to open the releng plugin mentioned in the above link.</p>
  
  <p>Any windows based text maniputaion scripting language will also help.</p>