3

On a website I'm working on now I need to set up a redirection that takes a query string into consideration.

Example:

http://www.domain.com/?id=86&name=John&ref=12d34 -> http://www.domain.com/?ref=12d34
http://www.domain.com/?ref=593x56&id=935 -> http://www.domain.com/?ref=593x56
http://www.domain.com/?ref=3v77l32 -> http://www.domain.com/?ref=3v77l32

So basically I need to find the ref parameter and it's value (whatever it's length) and append only that part to the new URL. The issue is the the ref parameter can appear anywhere within the URL.

Any help or guidance would be very much appreciated!

LazyOne
  • 158,824
  • 45
  • 388
  • 391
Tom Hartman
  • 1,183
  • 2
  • 11
  • 18

2 Answers2

5

RewriteRule does not work with query string directly -- you have to use RewriteCond for that.

Here is the rule -- it will redirect (301 Permanent Redirect) ANY URL that has more than 1 parameter in query string and 1 of them is ref

RewriteEngine On

RewriteCond %{QUERY_STRING} (^|&)ref=([^&]*)(&|$)
RewriteCond %{QUERY_STRING} !^ref=([^&]*)$
RewriteRule .* http://%{HTTP_HOST}%{REQUEST_URI}?ref=%2 [R=301,L]

For example:

  1. It will redirect http://www.example.com/hello.php?id=86&name=John&ref=12d34888&me=yes to the same URL but with ref parameter only: http://www.example.com/hello.php?ref=12d34888.

  2. It will do nothing if only ref parameter is present or no parameter at all, e.g. http://www.example.com/hello.php?ref=12d34888 or http://www.example.com/hello.php.

If such redirect should only work for website root hits, then change the RewriteRule line to this:

RewriteRule ^$ http://%{HTTP_HOST}/?ref=%2 [R=301,L]

(this is if placed in .htaccess file in website root folder -- if placed in server config / virtual host context the rule needs to be slightly tweaked).

http://www.example.com/?id=86&name=John&ref=12d34888&me=yes -> http://www.example.com/?ref=12d34888

If it has to be redirected to another domain, then replace %{HTTP_HOST} by domain specific name, e.g:

RewriteRule ^$ http://www.exampe.com/?ref=%2 [R=301,L]

It all has been tested before posting.

LazyOne
  • 158,824
  • 45
  • 388
  • 391
-1
RewriteEngine On
RewriteRule ref=(.*?) /?ref=$1 [L]

is about as simple as it guess, but this will screw up if the ref query var isn't the last thing in the line - it'll slurp up everything after ref= and redirect that to, so

/blah&ref=abc&blahblahblah

would turn into

/ref=abc&blahblahblah
Marc B
  • 356,200
  • 43
  • 426
  • 500
  • Thank you much Marc! I may indeed use this despite the caveat. Would you perhaps be able to point me in the right direction should I want to obtain the exact value instead of everything after the ref parameter? – Tom Hartman Aug 09 '11 at 17:24
  • Much obliged, I'll give that a shot. – Tom Hartman Aug 09 '11 at 17:39
  • 1
    `RewriteRule` does not work with query string parameters directly – LazyOne Aug 09 '11 at 17:42
  • Thanks LazyOne, what would you suggest I use instead? – Tom Hartman Aug 09 '11 at 17:55
  • 1
    @Tom See my answer. @Mark The pattern you provided is not safe, as it will also work if parameter's name has `ref` at the end, for example `myref`: `?myref=12345&id=56789` -- there is no `ref` parameter here. – LazyOne Aug 09 '11 at 18:15