function getImageUrls($input_string) {
   $matches = array();
   preg_match_all('/url\((.+?)\);/i', $input_string, $matches);
   return preg_replace('/url\((.+?)\);/i', '$1', $matches);
}

拉出匹配，然后格式化它们只保留url路径。

something like that anyways. pull the matches out and then format them to keep only the url path.