Apache mod_rewrite: redirecting subdomains to the HTTPS login page

I'm trying to accomplish this:

http://subdomain.server.com/ 开发者_高级运维should redirect to https://secure.server.com/login?subdomain, but http://subdomain.server.com/any-other-page should pass through as-is.

Can I accomplish this in the .htaccess file?

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Try this rule:

RewriteCond %{HTTP_HOST} !=secure
RewriteCond %{HTTP_HOST} ^([^/.]+)\.example\.com$
RewriteRule ^$ https://secure.example.com/login?%1

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RedirectMatch ^/?$ https://secure.server.com/login?subdomain