Why One Rewrite Rule Works and the Other Fails: Mastering Apache URL Rewrites

The article presents two Apache mod_rewrite configuration examples and analyzes their behavior.

First configuration (works)

# Enable RewriteEngine
RewriteEngine On
RewriteBase /

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^(/)?$ /wap.php?%{QUERY_STRING} [L]

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^/(\w+)\.php$ /$1.php?%{QUERY_STRING} [L]

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^(\w+)\.html$ /wap.php?controller=$1&%{QUERY_STRING} [L]

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^(\w+)\/(\w+)\.html$ /wap.php?controller=$1&action=$2&%{QUERY_STRING} [L]

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^(\w+)\/(\w+)\/( [\w\-\=\&\/a-zA-Z0-9_%]+)\.html$ /wap.php?controller=$1&action=$2&arguments=$3&%{QUERY_STRING} [L]

RewriteRule ^app\/$ /app.php [L]
RewriteRule ^(/)?$ /index.php [L]
RewriteRule ^/(\w+)\.php$ /$1.php [QSA,L]
RewriteRule ^(\w+)\.html$ /index.php?controller=$1 [QSA,L]
RewriteRule ^(\w+)\/(\w+)\.html$ /index.php?controller=$1&action=$2 [QSA,L]
RewriteRule ^(\w+)\/(\w+)\/( [\w\-\=\&\/a-zA-Z0-9_%]+)\.html$ /index.php?controller=$1&action=$2&arguments=$3 [QSA,L]

This configuration correctly captures parameters such as p=2 from URLs like http://m.zcyy.dev/auction/index/type/auction.html?p=2, returning p=2 as expected.

Second configuration (fails)

# Enable RewriteEngine
RewriteEngine On
RewriteBase /

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^(/)?$ /wap.php [L]

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^/(\w+)\.php$ /$1.php [L]

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^(\w+)\.html$ /wap.php?controller=$1 [L]

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^(\w+)\/(\w+)\.html$ /wap.php?controller=$1&action=$2 [L]

RewriteCond %{HTTP_HOST} ^m.zcyy.dev [NC]
RewriteRule ^(\w+)\/(\w+)\/( [\w\-\=\&\/a-zA-Z0-9_%]+)\.html$ /wap.php?controller=$1&action=$2&arguments=$3 [L]

RewriteRule ^app\/$ /app.php [L]
RewriteRule ^(/)?$ /index.php [L]
RewriteRule ^/(\w+)\.php$ /$1.php [QSA,L]
RewriteRule ^(\w+)\.html$ /index.php?controller=$1 [QSA,L]
RewriteRule ^(\w+)\/(\w+)\.html$ /index.php?controller=$1&action=$2 [QSA,L]
RewriteRule ^(\w+)\/(\w+)\/( [\w\-\=\&\/a-zA-Z0-9_%]+)\.html$ /index.php?controller=$1&action=$2&arguments=$3 [QSA,L]

This version fails to retrieve the query string, so a request like http://m.zcyy.dev/auction/index/type/auction.html?p=2 does not return the p parameter.

The key difference is the omission of %{QUERY_STRING} in the rewrite rules of the second configuration; without it, the original query parameters are discarded, preventing proper parameter extraction.

When the same path is accessed via the domain www.zcyy.dev, the parameter is correctly captured because the rule set for that host includes the %{QUERY_STRING} placeholder.