PHP脚本：将任何网页转换为RSS提要xml

there is someone who knows how to write php in a script to convert a site's news into RSS feeds. For example, feed43.com, try it out to understand the mechanism. Thank you.

I tried to write this code, but I'm not capable. Help me please, it's not difficult.

function example_extract_link_feedrss($url){
  $link = file_get_contents($url);
   $str = trim(preg_replace('/\s+/', ' ', $str));
    preg_match('/\<h3\>"\>(.*)/i',$str,$titleNoticeRSS);
    return $titleNoticeRSS[1];
  }
}

Do NOT use regex to parse HTML! Please see here: RegEx match open tags except XHTML self-contained tags

Instead, use the DOM classes: http://php.net/manual/en/book.dom.php