在CodeIgniter 1.7.2中允许URL参数

I am using CodeIgniter version 1.7.2. I need to allow url parameters, for example

http://www.mydomain.com/?test=test. 

I try to change uri_protocol from

   $config['uri_protocol'] = "AUTO" 

to

   $config['uri_protocol'] = "PATH_INFO" 

and it worked but then all my other links like

http://www.mydomain.com/test  does not work. 

What is solution here?

I also tried to use permitted_uri_chars

but I can't made it work.

The above link from swatkins answers your question but I would have a serious think about using this approach, it's messy, search engines are not big fans and it opens up security vulnerabilities and I really can't think of any good reason to do it.

You can use a get request with a standard URI and pass your parameters via that, using this approach will encourage you to process and check input properly.