PHP-General - Help Needed -how to track Website changes?

Hi,

Sorry if I have posted this in the complete wrong place. I have no knowledge on web programming what so ever.

I was hoping someone could help out.

Is there a way to track certain changes to other websites?

I work for a manufacturers sales rep firm. Ideally, we want to rep the best manufacturers'. If you can imagine, the best are usually already taken, unless that manufacturer feels that rep firm isn't doing well for them. At that point, the rep firm gets dropped, and usually the rep firm will remove them from their website.

Thats where we want to take action and pick up these manufacturers while they are open. However, its very hard to find out without constantly checking every rep firms website. Either that, or just word of mouth.

It would be great if there was a way to track the removal of say, certain links (manufacturer's links) or images from a certain web page. Ideally, we would want to get notified when a change occurs, and then we can go see what link was removed.


For example, thsi rep firm lists all their Manufacturers here:
http://www.yando.com/caline.htm

Say CREE Microwave is removed. We would want some way to be notified when that happens.

Any ideas on how to achieve this?

This would not necessarily need PHP. If I were doing this I would periodically grab the pages of interest and store them somewhere. I'd then do a diff on the latest page and the corresponding previously stored page. I would then analyze those diff's and make the appropriate notifications.

As a matter of personal preference I would use perl to do this.

Thanks for the reply. So at least it sounds like this can be done, and i'm not crazy

So my question is, how would one go about implementing this? I would find a developer that can write this code....and ideally get some sort of email notification when a certain link is removed?

There are already apps that do this check out this http://i.downloadsquad.switched.com/2010/02/08/10-free-ways-to-keep-track-of-changes-to-any-website-without-rss/