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turingmachine
Asked: 2010-08-12 00:57:29 +0800 CST

mod_rewrite: Use backreference from RewriteCond as CondPattern in another RewriteRule

  • 772

I try to use the first part of the fqdn as a rewrite target:

http://demo.dev.example.com/something => http://demo.dev.example.com/demo/something

RewriteCond %{HTTP_HOST} ^([a-z0-9-]+).dev.example.com [NC]
RewriteRule ^/(.*) http://%1.dev.example.com/%1/$1 [P]

This creates an endless loop. So I need another condition that checks if this request is already rewritten or not:

RewriteCond %{REQUEST_URI} !^/%1

Well this is not working, the documentation says nothing about using backreferences in CondPatterns, most possibly it's not supported.

RewriteCond %{REQUEST_URI} !^/demo

This works perfectly, but isn't dynamic.

apache-2.2 mod-rewrite

2 Answers

  1. Best Answer

    Solution/Workaround: reserve one hostname part for internal requests:

    RewriteCond %{HTTP_HOST} !^internal.dev.atizo.org [NC]
RewriteCond %{HTTP_HOST} ^([0-9a-z-]+).dev.atizo.org [NC]
RewriteRule ^/(.*) http://internal.dev.atizo.org/%1/$1 [P]
    • 2

  2. If you don't need to process any rules after the rewrite, just add the "L" = "last" option in the square brackets:

    RewriteRule ^/(.*) http://%1.dev.example.com/%1/$1 [P,L]

    • -2