Question

I am developing a site where users will have permalinks for them like user.domain.com or domain.com/user and i want to achieve this by php code. foe ex.
for username stack the permalink is stack and on going to stack.domain.com or domain.com/stack it should go to profile page of user!

Answer 1

Let’s split the two cases:

user.domain.com

For this to work, you should first configure your DNS so that *.domain.com points to your server. Then in index.php, you can check if $_SERVER["HTTP_HOST"] matches something.domain.com (using e.g. preg_match). After verifying something is a valid username, you can either display the user’s profile page or redirect to the profile.

Caution: make sure that any subdomain you use yourself, like for example www., is not a valid username.

domain.com/user

To implement this, you need to setup some kind of catch-all for non-existing pages. One way would be to instruct your webserver to serve a php-file when it encounters a 404. This file could then use the $_SERVER["REQUEST_URI"] variable to determin if there if a user profile is requested.

Caution: Make sure that any /something that is already a valid page is not a valid username. Alternatively you could use a prefix like domain.com/u/user to be more flexible in the names of your own pages.