Using question mark in CodeIgniter routing - php

Question

I need to change
http://mysite.com/profile?username=nick
to
http://mysite.com/user/nick
with CodeIgniter routing. I add the following line to routes.php but it doesn't work:
$route['user/(:any)'] = "profile?username=$1";
Here is the .htaccess file that I use:
RewriteEngine on
RewriteCond $1 !^(index\.php|resources|robots\.txt)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?/$1 [L,QSA]
AddDefaultCharset utf-8
How can I solve this problem? Thanks in advance.
EDIT:
I mean URL structure changing. So after the routing it must redirect
http://mysite.com/user/nick
to
http://mysite.com/profile?username=nick

Answer 1

Htaccess rule to handle the redirect:
RewriteRule user/([^/?]+) /profile?username=$1 [L,R=301]
Route.php change:
<?php
$route['profile'] = 'profile/index';
Profile controller:
<?php
class Profile extends CI_Controller {
public function index()
{
$username = $this->input->get('username');
// do lookup based on username
}
}
HOWEVER: this sort of redirection only makes sense if you have a lot of cached links that don't make sense to change. It sounds from your question that you might be confusing the concepts of routing and redirecting.
EDIT: To "route" (rather than "redirect"), here are the steps:
Htaccess rule to internally re-route requests:
RewriteRule /profile?username=([^&]*) index.php/user/$1 [L]
Route.php:
<?php
$route['user/(:any)'] = 'user/index/$1';
Controller:
<?php
class User extends CI_Controller {
public function index($username)
{
// ...
}
}
If that doesn't work, then, well, you're doing a terrible job explaining your problem :).

Answer 2

The issue most likely is that the ? is a special character in regular expression language meaning either 1 or 0. You will need to escape it for it to match, something like so should solve your issue:
$route['user/(:any)'] = "profile\?username=$1";

Answer 3

Okay, you want to do it the other way around. Try:
RewriteRule user/([^/?]+) index.php/profile?username=$1 [L]
Sorry if this doesn't work, my Apache isn't cooperating.