multiple applications setup

Hi Folks,
I am about to built a codeigniter website with a set of multiple applications .
Regarding the directory layout I would like to follow codeigniter standards https://ellislab.com/codeigniter/user-gu..._apps.html and organize the applications accordingly.
/codeigniter_root/application/appone
/codeigniter_root/application/apptwo
/codeigniter_root/application/appthree
What I am missing in the user guide is how should we manage the access to multiple applications.
The user guide mention only access to one specific application by defining “application_folder” in the config.php but the point is the access the application by adding application name as a suffix to the domain-name ex :
http://domain-name/appone , http://domain-name/apptwo , http://domain-name/appthree and I don't see this explanation in the document.
Could anybody point me to right direction?  

After you have installed app one, app two and app three create three index.php files in each app one, app two and app three folders, all with a common $system_folder and relevant $application_folder

$application_folder = "/appone/application"; // similar for app two and app three

Edit:
Have you thought about using sub-domains?

Hi John,  
Yes the subdomains is IMO the best solution but I don't have access to virtual host settings and customer is explicitly asking for the above solution. I will try your advice and will get back here with the output.
Thank you for your time.

Have you though about using $_SERVER variables where you can get the host that's trying to be accessed and then assign it's name to the $application variable that's in your root index.php file. You must use a system hook, also, to avoid/handle any errors with that workflow.

Here, I'll share some of my work: https://gist.github.com/josepostiga/7d46...69791705c5. Of course, you'll need to edit according to your specific needs, but I think will put you on the right track.

Best regards,
José Postiga
Senior Backend Developer