Cache folder write issues

I had to give my cache folder a chmod of 777 for my script to write to it. I think anybody could easily rewrite my pages in the cache folder to put whatever they want on my site. How can I just give php permission to write to the folder. I have tried every chmod I can think of and they all come back with a could not write error. I have to give the other permission to write to the folder and that bothers me greatly.

Does 777 work then?

777 doesn't let anyone in the world write/rewrite/execute your programs, It just opens up anything running on the server to be able to. It is generaly very unlikely that any of the other websites will manage to access your folder, your host should have protection against that. The main concern is if someone finds a security hole in your code, they could do some damage. Or if they manage to upload and execute a program.

Ok that cures my fears, yes 777 works great but I wasn't sure how secure it was.

777 just means read/write/execute any user/group on your speciifc server. If you are hosting your site on a shared server, it does in theory mean that another user could write to your folder. But most web hosts work on the theory that they can "trust" the users they host on their servers. In most cases this works fine. Someone else using that server would have no reason to write to your directory. If you are really worried about it, you should look for a host that runs something called "suexec", which allows you to have your folders as 700, (read/write only your user). Not many hosts run this though, as i said its never really an issue.