Creating Files With Yii

Hi.

Does yii have a premade class for creating files? With alle the functions in gii i would guess so, but i've googled it and looked for it, but i've had no luck. My apologies if theres threds about it allready. In the case that there is no such function, and fwrite is the way to go, what path-request would be the best practice? Ive encounterd some errors trying to use request->baseUrl..

Thanks in advance.