如何从PHP中的推文文本中获取图像URL？

Question

I'm currently displaying pics in my app from twitter's default image service since they get included in the json response but I'd like to try to get images from yfrog, twitpic, lockerz or similar providers.

I'm using the rest api so I was thinking about adding filter:links to the search query, extract the url from the tweet and check if the link is an image but I'm not sure exactly how to get the url since I assume it'll require some regular expressions plus most of the tweets url are shortened versions that redirect to the actual photo somewhere so I believe this could be a problem. It'd be nice if I could verify that the url contains any of the image providers mentioned above too (kind of like a first filter before checking if the url is an image)

Could someone point me in the right direction? Thanks in advance!

Answer 1

For detecting the links, just google for a regex to match a url. Like this here:
http://snipplr.com/view/2371/ or http://www.catswhocode.com/blog/15-php-regular-expressions-for-web-developers
and cycle through the matches array: http://php.net/manual/en/function.preg-match.php
This one should solve the short links problem (assuming you have curl installed):
follow redirects with curl in php
Use this here to check if the link is an image:
http://php.net/manual/en/function.get-headers.php (parse "Content-Type" for "image")

I hope this helps.