[Typo3] db access and user permissons outside of normal framework

[Volkmar K. Lecke]

Hi,


a component of my local extension should be a file, that has
    - access to TYPO3's database
        and
    - access to the fe-user-permissions (i.e. whether the user is logged in
or not)

I don't want to generate any HTML-Output over the TYPO3-Framework, but I
want to create a slim solution. So the php-file will be called outside of
TYPO3 but shall have access to the data defined within TYPO3.

According to my first research, i need for the database access the t3lib_db
class; which one is needed for checking the user permissions? How can they
be included in an elegant way?


Thanks
Volkmar