index.php

<?php

define('ENVIRONMENT', isset($_SERVER['CI_ENV']) ? $_SERVER['CI_ENV'] : 'development');

switch (ENVIRONMENT)
{
	case 'development':
		error_reporting(-1);
		ini_set('display_errors', 1);
	break;

	case 'testing':
	case 'production':
		ini_set('display_errors', 0);
		if (version_compare(PHP_VERSION, '5.3', '>='))
		{
			error_reporting(E_ALL & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT & ~E_USER_NOTICE & ~E_USER_DEPRECATED);
		}
		else
		{
			error_reporting(E_ALL & ~E_NOTICE & ~E_STRICT & ~E_USER_NOTICE);
		}
	break;

	default:
		header('HTTP/1.1 503 Service Unavailable.', TRUE, 503);
		echo 'The application environment is not set correctly.';
		exit(1); // EXIT_ERROR
}

$system_path = 'framework/system';
$application_folder = 'framework/app';
$view_folder = '';

// Set the current directory correctly for CLI requests
if (defined('STDIN'))
{
    chdir(dirname(__FILE__));
}

if (($_temp = realpath($system_path)) !== FALSE)
{
    $system_path = $_temp.'/';
}
else
{
    // Ensure there's a trailing slash
    $system_path = rtrim($system_path, '/').'/';
}

// Is the system path correct?
if ( ! is_dir($system_path))
{
    header('HTTP/1.1 503 Service Unavailable.', TRUE, 503);
    echo 'Your system folder path does not appear to be set correctly. Please open the following file and correct this: '.pathinfo(__FILE__, PATHINFO_BASENAME);
    exit(3); // EXIT_CONFIG
}

/*
 * -------------------------------------------------------------------
 *  Now that we know the path, set the main path constants
 * -------------------------------------------------------------------
 */
	// The name of THIS file
define('SELF', pathinfo(__FILE__, PATHINFO_BASENAME));

// Path to the system folder
define('BASEPATH', str_replace('\\', '/', $system_path));

// Path to the front controller (this file)
define('FCPATH', dirname(__FILE__).'/');

// Name of the "system folder"
define('SYSDIR', trim(strrchr(trim(BASEPATH, '/'), '/'), '/'));

// The path to the "application" folder
if (is_dir($application_folder))
{
    if (($_temp = realpath($application_folder)) !== FALSE)
    {
        $application_folder = $_temp;
    }

    define('APPPATH', $application_folder.DIRECTORY_SEPARATOR);
}
else
{
    if ( ! is_dir(BASEPATH.$application_folder.DIRECTORY_SEPARATOR))
    {
        header('HTTP/1.1 503 Service Unavailable.', TRUE, 503);
        echo 'Your application folder path does not appear to be set correctly. Please open the following file and correct this: '.SELF;
        exit(3); // EXIT_CONFIG
    }

    define('APPPATH', BASEPATH.$application_folder.DIRECTORY_SEPARATOR);
}

// The path to the "views" folder
if ( ! is_dir($view_folder))
{
    if ( ! empty($view_folder) && is_dir(APPPATH.$view_folder.DIRECTORY_SEPARATOR))
    {
        $view_folder = APPPATH.$view_folder;
    }
    elseif ( ! is_dir(APPPATH.'views'.DIRECTORY_SEPARATOR))
    {
        header('HTTP/1.1 503 Service Unavailable.', TRUE, 503);
        echo 'Your view folder path does not appear to be set correctly. Please open the following file and correct this: '.SELF;
        exit(3); // EXIT_CONFIG
    }
    else
    {
        $view_folder = APPPATH.'views';
    }
}

if (($_temp = realpath($view_folder)) !== FALSE)
{
    $view_folder = $_temp.DIRECTORY_SEPARATOR;
}
else
{
    $view_folder = rtrim($view_folder, '/\\').DIRECTORY_SEPARATOR;
}

define('VIEWPATH', $view_folder);

/*
 * --------------------------------------------------------------------
 * LOAD THE BOOTSTRAP FILE
 * --------------------------------------------------------------------
 *
 * And away we go...
 */

require_once BASEPATH.'core/CodeIgniter.php';