title: Matching two files with awk codes
body: <p>There are two files </p>
  
  <p>first.file</p>
  
  <ul>
  <li>M1</li>
  <li>M2</li>
  <li>M3</li>
  </ul>
  
  <p>...</p>
  
  <p>second.file </p>
  
  <ul>
  <li>A1 M1</li>
  <li>A2 M1</li>
  <li>A2 M3</li>
  <li>A3 M2</li>
  <li>A3 M4</li>
  <li>A3 M5</li>
  </ul>
  
  <p>....</p>
  
  <p>I want to match first.file to second.file My result file should be like that:</p>
  
  <p>result.file</p>
  
  <ul>
  <li>A1 M1</li>
  <li>A2 M1</li>
  <li>A2 M3</li>
  <li>A3 M2</li>
  </ul>
  
  <p>How can I do that with awk codes ? </p>
  
  <p>Thank you in advance</p>