PHP: how to write a file when no permissions are granted to www-data user

Question

I have a WEB-page on Apache/2.2.9 (Debian) server located in .../public_html I am a user with no root preveligies. I rewrote my site in PHP and noticed that it cannot write files in ../public_html I changed everything in the folder to 777 and the folder itself, but still when the PHP script is executed, nothing can be written by www-data user. So I cannot even log visitors of my web-site into a file. Is there some way to write something exported by www-data user?

Answer 1

The reason for this is probably to protect the server when people when do really stupid things like changing all the permissions to 777.

Being able to write data is a really essential capability for any application - the world wide web was originally designed a publishing medium but quickly became an application platform. There is no point in provisioning PHP on a webserver without the capability to persist data. So it seems highly improbable that the server is configured in such a way as to prevent you writing your data to a safe location. But that safe location is unlikely to be within ~/public_html. We don't know where that location is - your local systems admin / service provider should.

You should really take some time to learn about the security of PHP applications - there are lots of websites and a few good books on the topic.