Storing database settings

I'm writing this web application in php, and it involves filling out an html form which will set up the system. The form gets info like sql username, password, hostname, database name, etc. There's other settings too. I had this idea that it would be easy to store the data in a database table. That way I wouldn't have to write it to a file or anything. However, I can't connect to the database to get the info without having the info from the database.

Question 1: Does anyone have any suggestions, or should I just write the data to a file?

Question 2: How do I allow PHP to create a file without having write permissions set for everyone (I'm in linux and this means making the folder chmod'ed to 777, which is far from desirable)

I would just use a cookie to store the machine and database name at least. Each time the user tries to login, you can retrieve those items from the cookie and they could provide their username and password.

Computers don't have faith and that would be required for it to believe that another system is out their to connect to without having the properties :)