Typically there is a one-to-one relationship between a URL string and its corresponding controller class/method. The segments in a URI normally follow this pattern:

update_string($table, $data, $where)

set_status_header($code[, $text = ''])

last_row([$type = 'object'])

log_message($level, $message)

set_profiler_sections($sections)

CodeIgniter comes with an “Auto-load” feature that permits libraries, helpers, and models to be initialized automatically every time the system runs. If you need certain resources

strip_image_tags($str)

set_message($lang[, $val = ''])

clean()