Compressing PHP source code

<?php
/<strong>
 * Compact PHP code.
 *
 * Strip comments, combine entire library into one file.
 */
 
 
$source = '../src/QueryPath/QueryPath.php';
$target = 'QueryPath.compact.php';
 
include $source;
 
$files = get_included_files();
 
$out = fopen($target, 'w');
fwrite($out, '<?php' . PHP_EOL);
fwrite($out, '// QueryPath. Copyright (c) 2009, Matt Butcher.' . PHP_EOL);
fwrite($out, '// This software is released under the LGPL, v. 2.1 or an MIT-style license.' . PHP_EOL);
fwrite($out ,'// <a href="http://opensource.org/licenses/lgpl-2.1.php'" title="http://opensource.org/licenses/lgpl-2.1.php'">http://opensource.org/licenses/lgpl-2.1.php'</a>);
fwrite($out, '// <a href="http://querypath.org.'" title="http://querypath.org.'">http://querypath.org.'</a> . PHP_EOL);
foreach ($files as $f) {
  if ($f !== <strong>FILE</strong>) {
    $in = fopen($f, 'r');
    while (!feof($in)) {
      $line = fgets($in);
      $line = clean_line($line);
      fwrite($out, $line);
    }
    fclose($in);
  }
}
 
fclose($out);
 
/</strong>
 * Main cleaning function.
 */
function clean_line($line) {
  static $inComment = FALSE;
  if ($inComment) {
    $inComment = strpos($line, '*/') === FALSE;
    return '';
  }
  // The last condition rules out XPath with //* in them.
  elseif (!$inComment && strpos($line, '/*') !== FALSE && strpos($line, '//*') === FALSE) {
    $inComment = TRUE;
    return '';
  }
  elseif (strpos($line, 'require') === 0) {
    return '';
  }
  elseif (($p = strpos($line, '// ')) !== FALSE) {
    $line = substr($line, 0, $p);
    $line = trim($line);
    return empty($line) ? '' : $line . PHP_EOL;
  }
  elseif (strpos($line, '<?php') !== FALSE) {
    return '';
  }
  elseif (strpos($line, '//') === FALSE && in_array(substr($line, strlen($line) -2, 1), array('}',':',',',';'))) {
    $line = rtrim($line);
  }
  return ltrim($line);
}
?>