通过PHP离开网站免责声明？

Question

Due to legal reasons, I want every external hyper link posted on my forum to first link to a You're leaving this website and are being redirected to a website that is not our property... -disclaimer page. Something like http://www.mydomain.com/?leave=FINALURLHERE would do fine, but how do I set up this system?

I can easily make a script that does it for all URLs, but I only want this to happen to external URLs. Can anybody push me towards the right direction?

Answer 1

Presumably you're using some form of BBCode on your forums. You can just edit that to add your leaving page first.

If you're not, then you'll have to resort to some rather messy JavaScript. Something like:

var links = document.getElementsByTagName('a'), l = links.length, i,
    domain = location.protocol+"//"+location.hostname+"/";
for( i=0; i<l; i++) {
    if( links[i].href.substr(0,domain.length) != domain) {
        links[i].href = "/exit.php?target="+encodeURIComponent(links[i].href);
    }
}