如何设置负的reg表达式匹配以拉出所有其他链接

Question

Hi I have the following html and want to pull out all the other links that are not http://dont-match.co.uk all the URLs to be matched are different all the ones not to be matched are the same hence I'm thinking along the lines of a negative match ie match all that are not http://dont-match.co.uk

<a href="http://match-this-url.com/">link text</a> some 
text <a href="http://match-this-diff-url.com/">link text</a> more 
text <a href="http://dont-match.co.uk/">link text</a> 
text <a href="http://match-this-different-url.com/">link text</a> 
text <a href="http://dont-match.co.uk/">link text</a>

This is what i have so far:

/(<a href="http:\/\/[dont-match.co.uk]\/[^\"]*">([\d\D]*?)<\/a>)/

Answer 1

Use a negative lookahead (?!expression not to match):

preg_match_all('/(<a href="http:\/\/(?!dont-match\.co\.uk).*?\/[^"]*">(.*?)<\/a>)/', $str, $matches);