Is it possible to get more than 20 posts by rss.xml 2.0?

Question

PHP

Hello connoisseurs! I decided to write a small news grabber from one site, I considered rss parsing to be the best solution, but there you can only get the last 20, and I would like to get all the posts, is this real?
rss format:

<rss xmlns:dc="http://purl.org/dc/elements/1.1/" version="2.0">

and additional the question is, is it possible to get the full news, and not the announcement?
Thank you for your attention!

Answer 1

try to get rss through third party services like feedburner, feedly

Answer 2

This will only depend on the RSS provider. If he only has 20 pieces, then you will only get 20. So there are full texts or only announcements. You can, of course, collect the history to your server ... But this complicates it.
So you have to parse the site for the sake of full texts.