Php file protection, anti-download problems

Php file protection to prevent downloading problems: users can read files in a folder after passing session verification. However, you do not want to obtain the file directly from the URL path when the user does not pass the verification. How can I set such permissions and programming? (Virtual host) grateful. do not expose files directly. php reads files and outputs them to users. support the ls statement. you can also consider using php file protection to prevent downloading.
Requirements:
After session verification, you can read files in a folder.
However, you do not want to obtain the file directly from the URL path when the user does not pass the verification.
How can I set such permissions and programming? (Virtual host)
Grateful

------ Solution --------------------
Do not directly expose the path of the file. php reads the file and outputs it to the user.
------ Solution --------------------
Supports the ls statement.

Or you can consider using permissions.
------ Solution --------------------
Use rewrite technology htaccess rewrite
Add. htaccess to restrict the access path here
------ Solution --------------------
In this case, add
If (user session verification)
Define ('denglule', true );

Check on the logon page
If (denglule)
Include ('index. php'); // true
Echo 'wrong door, out'; // false