Question

I am running WordPress 3.1 with multisite enabled. I have multiple websites all sharing the same .htaccess file in the web root directory. I am using RewriteCond to target specific websites and apply RewriteRules to each site. Unfortunately it is not working as expected. Here is what I have in my .htaccess file:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# Blog1 Rewrite Rules which should only apply to blog1.mydomain.com
RewriteCond %{HTTP_HOST} ^blog1\.mydomain\.com [nc]
RewriteRule ^fileabc\.jpg$ http://blog1.mydomain.com/files/2011/05/fileabc.jpg [R=301,NC,L]
RewriteRule ^filexyz\.pdf$ http://blog1.mydomain.com/wp-content/themes/blog1Theme/Files/filexyz.pdf [R=301,NC,L]

# Blog2 Rewrite Riles which should only apply to blog2.com
RewriteCond %{HTTP_HOST} ^Blog2\.com [nc]
RewriteRule ^index\.html$ http://Blog2.com/index.php [R=301,NC,L]
RewriteRule ^page\.html$ http://Blog2.com/page/ [R=301,NC,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule . index.php [L]

I use RewriteCond to target a specific site (blog1.mydomain.com or blog2.com) and they have specific RewriteRules for each.

However, The ReWriteRules are being applied to both websites (blog1.mydomain.com and blog2.com).

For example:

Accessing blog1.mydomain.com/fileabc.jpg should redirect to http://blog1.mydomain.com/files/2011/05/fileabc.jpg

However, accessing Blog2.com/fileabc.jpg also redirects to http://blog1.mydomain.com/files/2011/05/fileabc.jpg

So the RewriteRules are being applied to both (all) site, not just the ones specified by the RewriteCond.

Help is much appreciated!

Answer 1

From Apache page

The order of rules in the ruleset is
important because the rewrite engine
processes them in a particular (not
always obvious) order, as follows: The
rewrite engine loops through the
rulesets (each ruleset being made up
of RewriteRule directives, with or
without RewriteConds), rule by rule.
When a particular rule is matched,
mod_rewrite also checks the
corresponding conditions (RewriteCond
directives). For historical reasons
the conditions are given first, making
the control flow a little bit
long-winded.

first the URL is matched against the
Pattern of a rule. If it does not
match, mod_rewrite immediately stops
processing that rule, and goes on to
the next rule. If the Pattern matches,
mod_rewrite checks for rule
conditions. If none are present, the
URL will be replaced with a new
string, constructed from the
Substitution string, and mod_rewrite
goes on to the next rule.

Now your rules

RewriteCond %{HTTP_HOST} ^blog1\.mydomain\.com [nc]
RewriteRule ^fileabc\.jpg$ http://blog1.mydomain.com/files/2011/05/fileabc.jpg [R=301,NC,L]
RewriteRule ^filexyz\.pdf$ http://blog1.mydomain.com/wp-content/themes/blog1Theme/Files/filexyz.pdf [R=301,NC,L]

RewriteCond is valid only for first rewriteRule immediately following it , not for all rules below it.So second rewriteRule will match any domain.