Directories, Accounts and PHP

I am currently undertaking building a website and am learning PHP in order to create an account system. The script is using directories to hold account information as I've written a code that creates a separate directory for each user upon registration. I was wondering if it would be possible to authenticate a user within a session through using directories (and not databases) so that they would need to be logged in, in order to upload images, write articles and so forth. For instance, say I've logged into the site, the code searches the text file with the account info and authenticates a user. Now, since I've been authenticated, how would I get this to carry over from the login page itself into the upload page, the articles page and so forth? What function should I be using to authenticate users in a directory?

If using directories is simply not practical in this sense because it hinders functionality, then I suppose I'll have to learn to use databases. So far, what I'm using is working though.

learning PHP
Use node.js instead.

Any particular reasons I should be using node.js instead?

It was designed especially for the web.

chode.anus

node.js and javascript are functional languages, which means you must only use functions because they are faster.

>>1
building a website ... PHP
Eat shit and die

>>5
>le pedophile sage
>>6
>le pedophile sage