301 Redirecting URLs based on GET variables in .htaccess

Question

I have a few messy old URLs like...

http://www.example.com/bunch.of/unneeded/crap?opendocument&part=1

http://www.example.com/bunch.of/unneeded/crap?opend

Answer 1

As the parameters in the URL query may have an arbitrary order, you need to use a either one RewriteCond directive for every parameter to check or for every possible permutiation.

Here’s an example with a RewriteCond directive for each parameter:

RewriteCond %{QUERY_STRING} ^([^&]&)*opendocument(&|$)
RewriteCond %{QUERY_STRING} ^([^&]&)*part=1(&|$)
RewriteRule ^bunch\.of/unneeded/crap$ /page.php/welcome? [L,R=301]

RewriteCond %{QUERY_STRING} ^([^&]&)*opendocument(&|$)
RewriteCond %{QUERY_STRING} ^([^&]&)*part=2(&|$)
RewriteRule ^bunch\.of/unneeded/crap$ /page.php/prices? [L,R=301]

But as you can see, this may get a mess.

So a better approach might be to use a RewriteMap. The easiest would be a plain text file with key and value pairs:

1 welcome
2 prices

To define your map, write the following directive in your server or virual host configuration (this directive is not allowed in per-directory context):

RewriteMap examplemap txt:/path/to/file/map.txt

Then you would just need one rule:

RewriteCond %{QUERY_STRING} ^([^&]&)*opendocument(&|$)
RewriteCond %{QUERY_STRING} ^([^&]&)*part=([0-9]+)(&|$)
RewriteRule ^bunch\.of/unneeded/crap$ /page.php/%{examplemap:%2}? [L,R=301]