Specify Multiple Subdomains with Access Control Origin

Question

I am trying to allow access to every subdomain on my site in order to allow cross subdomain AJAX calls. Is there a way to specify all subdomains of a site like *.example.c

Answer 1

If you want wildcard domain, i think this is more efficient

if(isset($_SERVER['HTTP_ORIGIN']) && preg_match('!^http(s)?://([a-z0-9\-]+\.)?example.com$!is', $_SERVER['HTTP_ORIGIN']))
{
    header('Access-Control-Allow-Origin: '.$_SERVER['HTTP_ORIGIN']);
}