Apache rewrite server subdomains into directories

  # To rewrite server subdomains into directories: Capture the subdomains
  # in a rewrite condition, then use backreferences to them in the rule.
  # . run apache locally
  # . add project.client.staging.domain.com to /etc/hosts
  # . curl project.client.staging.domain.com
  # . in rewrite_log, you'll see  rewrite '/' -> '/root/staging/client/project'
  RewriteLogLevel 3
  RewriteLog "rewrite_log"
  RewriteEngine On
  ServerName project.client.staging.domain.com
  RewriteCond %{SERVER_NAME} ^(.*?)\.(.*?)\.(.*?)\.
  RewriteRule ^.*$ /root/%3/%2/%1 [L]