How do I run CodeIgniter migrations?

Using these pages as references: Running via the CLI
and Migration Class
you’re able to restrict access to your migration controller to command line with something along these lines (application/controllers/migrate.php):

<?php  if ( ! defined('BASEPATH')) exit("No direct script access allowed");

class Migrate extends CI_Controller {

  public function __construct()
  {
    parent::__construct();

    $this->input->is_cli_request()
      or exit("Execute via command line: php index.php migrate");

    $this->load->library('migration');
  }

  public function index()
  {
    if(!$this->migration->latest())
    {
      show_error($this->migration->error_string());
    }
  }
}

then to execute your latest migration, cd into the root of your project directory and run:

php index.php migrate

but when you attempt to access via webserver example.com/migrate you will see the text in the script above.