the steps to prepare CodeIgniter 2.x for cron-jobs via CLI (command line interface):
1st: create a copy of your root index.php file and save it in your root as cli.php
2nd: in your cli.php replace <?php with this code:
#!/usr/local/bin/php
<?php
/* override normal limitations */
set_time_limit(0);
ini_set('memory_limit', '256M');
/* deny direct call from web browser */
if (isset($_SERVER['REMOTE_ADDR'])) die('Permission denied.');
/* constants */
define('CMD', 1);
/* manually set the URI path based on command line arguments... */
unset($argv[0]); /* except the first one */
$_SERVER['QUERY_STRING'] = $_SERVER['PATH_INFO'] = $_SERVER['REQUEST_URI'] = "https://stackoverflow.com/" . implode("https://stackoverflow.com/", $argv) . "https://stackoverflow.com/";
3rd: execute your cron job like this:
/usr/bin/php /var/www/website/public_html/cli.php controller method
where /var/www/website/public_html/ is your server’s home directory, the location of your index.php and cli.php.
notes:
for CI 3.0 you find the necessary information here
database: you’ll need to provide your db config settings in your controller method, as the cron job just executes the controller’s method. So it doesn’t know anything about any database settings!
$config['hostname'] = "localhost";
$config['username'] = "username_admin";
$config['password'] = "password";
//etc..
$this->db = $this->load->database($config, TRUE);
debug: just add a link in your html to run your controller’s method like: index.php/controller/method (remove that once you website is live)
source: very helpful