CodeIgniter .htaccess用于我的文件结构

I was handed down a project from another developer (who's not available any more and I cannot ask him for a solution) where he'd kept multiple codeignitor projects in a folder and called each of them through their respective index files.

The file structure - /var/www/html/{folder}/mobile_index.php

The mobile_index.php references a folder 'mobile' which resides in the same folder as mobile_index.php.

So the URL that I call is - "xx.xx.xx.xx/{folder}/mobile_index.html". This page opens fine but when I click on any link (e.g. user) within the page, this redirects to "xx.xx.xx.xx/user"

Now this page is blank and my error log says there's no page user in /var/www/html/user. But when i manually convert the link to "xx.xx.xx.xx/{folder}/mobile_index.php/user" this works and opens up the page. I think the folder is missing the .htaccess file but I have no clue what to include in that file, can anyone help me get the links working again?

This is what I have so far -

    RewriteEngine on 
    RewriteCond $1 !^(mobile_index\.php|images|robots\.txt) 
    RewriteRule ^(.*)$ /{folder}/mobile_index.php/$1 [L]
Options +FollowSymLinks
RewriteEngine On
#RewriteBase / #on server, uncomment this line by removing hash'#'
RewriteBase /

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule .* mobile_index.php?/$0 [PT,L,QSA]