Recursively find files by filename pattern. (See related posts)

function my_handler($filename) {
  echo $filename . "\n";
}
find_files('c:/', '/php$/', 'my_handler');

function find_files($path, $pattern, $callback) {
  $path = rtrim(str_replace("\\", "/", $path), '/') . '/';
  $matches = Array();
  $entries = Array();
  $dir = dir($path);
  while (false !== ($entry = $dir->read())) {
    $entries[] = $entry;
  }
  $dir->close();
  foreach ($entries as $entry) {
    $fullname = $path . $entry;
    if ($entry != '.' && $entry != '..' && is_dir($fullname)) {
      find_files($fullname, $pattern, $callback);
    } else if (is_file($fullname) && preg_match($pattern, $entry)) {
      call_user_func($callback, $fullname);
    }
  }
}