Replacing a querystring parameter value using mod_rewrite

Question

I would like to map this:

http://www.example.com/index.php?param1=value1¶m2=value2¶m3=value3 (etc. ad infinitum)

to

Answer 1

Try this rule:

RewriteCond %{QUERY_STRING} ^(([^&]*&)*)param1=value1(&.*)?$
RewriteRule ^index\.php$ /index.php?%1param1=newvalue1%3 [L,R=301]