How to check if a site has rss feeds

问题

Suppose I want to make a webpage that takes domain name of a website as input and checks if that site has rss feeds or not. And if that site has rss feeds, it proceeds to the next page. Or in other words, just check if that given domain name has this tag or not-

<link rel="alternate" type="application/rss+xml" 
      title="Something" 
      href="http://www.example.com/feed1.xml” />

How do I do it using php or javascript ?

回答1:

Due to the same-origin policy, you won't be able to implement that in JavaScript, you'll need PHP.

Download and parse the page, and search for the xpath html>head>link[@rel='alternate'].

来源：https://stackoverflow.com/questions/5450501/how-to-check-if-a-site-has-rss-feeds