Codeigniter Class and filename case sensitive on Linux (centos)

Codeigniter change log says

Changed filenaming convention (class file names now must be Ucfirst and everything else in lowercase).

So you controllers and files name should be

• My_controller (only M upper case rest lower case)
• Public_controller
• Application_controller
• Foo_controller

I myself don't like new naming convention CI-2 was better in this case.

Note:

Controller name Public_Controller(C uppercase) and file name Public_controller.php may work but I prefer to keep both name same so controller name should be Public_controller.

As @jagad89 said, your filename for application_controller.php should be as the codeigniter upgrade guide specifies: "... must be named in a Ucfirst-like manner or in other words - they must start with a capital letter." so Application_controller.php

Meaning all of your Controllers, Models, Libraries, and Drivers (NOT HELPERS) have to be named in this manner to be able to be used inside of codeigniter.

For sake of unity, your class definition should match the filename as you said.

You should see the 500 errors in your log, at least on linux, at /var/log/apache2/error.log which should help with your debugging process.

my solutionin the /application/core/ i create a MY_Loader.php (uppercase for MY_L)
I create a class MY_Loader with a copy of original function "model"
I comment the line "$model = ucfirst($model);"

The code of /application/core/MY_Loader.php:

class MY_Loader extends CI_Loader{    /*this a copy of function model of the class CI_Loader from /system/core/Moader.php */    public function model($model, $name = '', $db_conn = FALSE)    {        if (empty($model))        {            return $this;        }        elseif (is_array($model))        {            foreach ($model as $key => $value)            {                is_int($key) ? $this->model($value, '', $db_conn) : $this->model($key, $value, $db_conn);            }            return $this;        }        $path = '';        // Is the model in a sub-folder? If so, parse out the filename and path.        if (($last_slash = strrpos($model, '/')) !== FALSE)        {            // The path is in front of the last slash            $path = substr($model, 0, ++$last_slash);            // And the model name behind it            $model = substr($model, $last_slash);        }        if (empty($name))        {            $name = $model;        }        if (in_array($name, $this->_ci_models, TRUE))        {            return $this;        }        $CI =& get_instance();        if (isset($CI->$name))        {            throw new RuntimeException('The model name you are loading is the name of a resource that is already being used: '.$name);        }        if ($db_conn !== FALSE && ! class_exists('CI_DB', FALSE))        {            if ($db_conn === TRUE)            {                $db_conn = '';            }            $this->database($db_conn, FALSE, TRUE);        }        // Note: All of the code under this condition used to be just:        //        //       load_class('Model', 'core');        //        //       However, load_class() instantiates classes        //       to cache them for later use and that prevents        //       MY_Model from being an abstract class and is        //       sub-optimal otherwise anyway.        if ( ! class_exists('CI_Model', FALSE))        {            $app_path = APPPATH.'core'.DIRECTORY_SEPARATOR;            if (file_exists($app_path.'Model.php'))            {                require_once($app_path.'Model.php');                if ( ! class_exists('CI_Model', FALSE))                {                    throw new RuntimeException($app_path."Model.php exists, but doesn't declare class CI_Model");                }            }            elseif ( ! class_exists('CI_Model', FALSE))            {                require_once(BASEPATH.'core'.DIRECTORY_SEPARATOR.'Model.php');            }            $class = config_item('subclass_prefix').'Model';            if (file_exists($app_path.$class.'.php'))            {                require_once($app_path.$class.'.php');                if ( ! class_exists($class, FALSE))                {                    throw new RuntimeException($app_path.$class.".php exists, but doesn't declare class ".$class);                }            }        }        //~ $model = ucfirst($model);/*this the line that i comment*/        if ( ! class_exists($model, FALSE))        {            foreach ($this->_ci_model_paths as $mod_path)            {                if ( ! file_exists($mod_path.'models/'.$path.$model.'.php'))                {                    continue;                }                require_once($mod_path.'models/'.$path.$model.'.php');                if ( ! class_exists($model, FALSE))                {                    throw new RuntimeException($mod_path."models/".$path.$model.".php exists, but doesn't declare class ".$model);                }                break;            }            if ( ! class_exists($model, FALSE))            {                throw new RuntimeException('Unable to locate the model you have specified: '.$model);            }        }        elseif ( ! is_subclass_of($model, 'CI_Model'))        {            throw new RuntimeException("Class ".$model." already exists and doesn't extend CI_Model");        }        $this->_ci_models[] = $name;        $CI->$name = new $model();        return $this;    }   }