How To Discover RSS Feeds for a given URL

Question

I get a URL from a user. I need to know:
a) is the URL a valid RSS feed?
b) if not is there a valid feed associated with that URL

using PHP/Javascript or s

Answer 1

For Perl, there is Feed::Find , which does automate the discovery of syndication feeds from the webpage. The usage is quite simplicistic:

use Feed::Find;
my @feeds = Feed::Find->find('http://example.com/');

It first tries the link tags and then scans the a tags for files named .rss and something like that.