How to let PHP to create subdomain automatically for each user?

Question

How do I create subdomain like http://user.mywebsite.com ? Do i have to access htaccess somehow? Is it actually simply possible to create it via pure php code or I need to u

Answer 1

Simple PHP solution for subdomains and multi-domain web apps

Step 1. Provide DNS A record as "*" for domains (or domain) you gonna serve "example.org"

A record => *.example.org
A record => *.example.net

Step 2. Check uniquity of logins when user registering or changing login. Also, avoid dots in those logins.

Step 3. Then check the query

        // Request was http://qwerty.example.org
        $q = explode('.', $_SERVER['HTTP_HOST']);
        /*
            We get following array
            Array
            (
                [0] => qwerty
                [1] => example
                [2] => org
            )
        */

        // Step 4.
        // If second piece of array exists, request was for 
        // SUBDOMAIN which is stored in zero-piece $q[0]
        // otherwise it was for DOMAIN

        if(isset($q[2])) {
            // Find stuff in database for login $q[0] or here it is "qwerty"
            // Use $q[1] to check which domain is asked if u serve multiple domains
        }

?>

This solution may serve different domains

qwerty.example.org
qwerty.example.net 

johnsmith.somecompany.com
paulsmith.somecompany.com

If you need same nicks on different domains served differently, you may need to store user choise for domain when registering login.

smith.example.org // Show info about John Smith
smith.example.net // Show info about Paul Smith