How to implement real time sub domain in PHP?

Suppose domain is domain.name,

after a new user sign up,need to generate a new domain:user1.domain.name.

How to impleme开发者_开发问答nt it?

BTW,is there a limit for the number of sub domains?

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I would simply use a wildcard to point all subdomains to a certain directory and have a front controller there that determines the used one from the URL - this is the easiest and safest solution from PHP.

EDIT Then you can obviously check whether that one should be existing (store them in a database or whatever) etc.

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What you are asking for is known as Wildcard DNS record:

• http://en.wikipedia.org/wiki/Wildcard_DNS_record

Basic DNS/Apache setup:

• http://ma.tt/2003/10/wildcard-dns-and-sub-domains/

App-side logic (crappy code):

• http://sebastiano.ezion.cc/2008/03/08/wildcard-dns-and-php/

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Subdomains can be retrieved with .htaccess (you need however wildcard mentioned earlier in this thread):

RewriteEngine On
RewriteCond %{HTTP_HOST} ^user([0-9]{1,10}).domain.name$
RewriteRule ^.*$ index.php?subdomain=%1