title: How to use shell ,bash or sed command in this situation
body: <p>i have this file</p>
  
  <pre>
  name1
  name2
  name3
  </pre>
  
  <p>and how to achieve this result :</p>
  
  <pre>
  first
  user:name1
  end
  
  first
  user:name2
  end
  
  first
  user:name3
  end
  </pre>
  
  <p>i could use <code>sed 's#^#user:#'</code> to achieve</p>
  
  <pre>
  user:name1
  user:name2
  user:name3
  </pre>
  
  <p>but still not finish the job .any one help me .Thanks</p>