Dynamic RewriteBase for Apache (mod_rewrite, mod_setenvif)

.htaccess

RewriteEngine On

#----------------------------------------------------------
# RewriteBase for develop
#----------------------------------------------------------
# SetEnvIf
SetEnvIf Host ^develop.example.com$ REWRITE_BASE=/path/to/develop

# or RewriteCond
#RewriteCond %{HTTP_HOST} ^develop.example.com$
#RewriteRule . - [E=REWRITE_BASE:/path/to/develop]

#----------------------------------------------------------
# RewriteBase for staging
#----------------------------------------------------------
# SetEnvIf
SetEnvIf Host ^staging.example.com$ REWRITE_BASE=/path/to/staging

# or RewriteCond
#RewriteCond %{HTTP_HOST} ^staging.example.com$
#RewriteRule . - [E=REWRITE_BASE:/path/to/staging]

#----------------------------------------------------------
# RewriteBase for production
#----------------------------------------------------------
# SetEnvIf
SetEnvIf Host ^www.example.com$ REWRITE_BASE=/path/to/production

# or RewriteCond
#RewriteCond %{HTTP_HOST} ^www.example.com$
#RewriteRule . - [E=REWRITE_BASE:/path/to/production]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !\.(ico|gif|jpe?g|png|css|js)$ [NC]
RewriteRule ^(.*)$ %{ENV:REWRITE_BASE}/index.php [QSA,NS,L]