function mytheme_preprocess_page() {
  global $user;
  $user = user_load($user->uid); // Make sure the user object is fully loaded

  $vars['full_name'] = $user->field_full_name[LANGUAGE_NONE][0]['value'];
}

然后在page.tpl.PHP中这样的事情：

if (isset($full_name) && !empty($full_name)) :
  echo 'Hello ' . $full_name;
endif;

请注意,如果您正在运行多语言网站,则可能需要更改LANGUAGE_NONE.