Let's say I've created a text-file with some data in it. How do I do to "get it out"?! Should I include it just like an ordinary page, or what?!
Accessing data?!
if I stored usernames and passwords (for instance) in them, and want to use those datas to verify a user when he/she login...
Sounds like you'll store information on each line of the file so [man]file/man looks like a good function for this job. [man]file/man will open the entire file though so if it's large or if you want to be efficient, use [man]fopen/man and [man]fgets/man.
After using file, loop through the array with [man]foreach[/man] and compare the data. You'll want to [man]explode/man each line for the username and password, and do this explode within the loop, along with your checking.
The most effective way is to store the username/Password in an array.
something like $list[username]=password
Then serialise the list and store it in the file.
while fetching just read the file as whole and unserialise the contents and you will again have the whole array to iterate through to find the username and password combination.
Hope this helps.