is_supported($driver)

limit($value[, $offset = 0])

get_header($header)

delete_file($filepath)

version()

array_replace(array $array1[, ...])

CodeIgniter has a config file that lets you store your database connection values (username, password, database name, etc.). The config file is located at application/config/database

form_dropdown([$name = ''[, $options = array()[, $selected = array()[, $extra = '']]]])

camelize($str)

mark_as_temp($key[, $ttl = 300])