Permissions for writing to different domains

I have a dedicated server and need to use php to write/edit/delete files to different domains on my server. The php files that will do the writing are in I want my script to write to the directories of,, etc. Do I need to set permissions anywhere in order to do this or will it work straight away?

If PHP is running as PHP-CGI, it should “just work”.
If it is running as an apache module as the apache user, you’ll need to set your directory you want to write to writable by world (777).