title: how to compare lines of two files and change the matched line in one file in tcl
body: <p>tcl</p>
  <p>I wanna compare two files line by line.</p>
  <p>file1</p>
  <ol>
  <li>abc</li>
  <li>123</li>
  <li>a1b2c3</li>
  </ol>
  <p>file2</p>
  <ol>
  <li><h2>abc</h2>
  </li>
  <li><h2>00 a1b2c3</h2>
  </li>
  </ol>
  <p>if the line of file1 matched one of the line of file2, change the line of file1  to the line of file2</p>
  <p>so the output file woule be like that.</p>
  <p>file1</p>
  <ol>
  <li><h2>abc</h2>
  </li>
  <li>123</li>
  <li><h2>00 a1b1c3</h2>
  </li>
  </ol>
  <p>please help me
  thank you</p>