Example of detecting links in a text string with PHP preg_replace()

This is an example of the ORIGINAL POST "How to detect links in a text string with PHP".

Original string

http://www.anerbarrena.com https://www.facebook.com www.google.es @anerbarrena #anerbarrena

Filtered string with normal links

http://www.anerbarrena.com https://www.facebook.com www.google.es @anerbarrena #anerbarrena

Filtered string with normal and Twitter format links

http://www.anerbarrena.com https://www.facebook.com www.google.es @anerbarrena #anerbarrena