<?php namespace Faker\Provider\pt_BR; /** * Calculates one MOD 11 check digit based on customary Brazilian algorithms. * * @see http://en.wikipedia.org/wiki/Check_digit * @see http://pt.wikipedia.org/wiki/CNPJ#Algoritmo_de_Valida.C3.A7.C3.A3o * @see http://en.wikipedia.org/wiki/Cadastro_de_Pessoas_F%C3%ADsicas#Validation * * @param int|string $numbers Numbers on which generate the check digit * * @return int */ function check_digit($numbers) { $numbers = (string) $numbers; $length = strlen($numbers); $second_algorithm = $length >= 12; $verifier = 0; for ($i = 1; $i <= $length; ++$i) { if (!$second_algorithm) { $multiplier = $i + 1; } else { $multiplier = ($i >= 9) ? $i - 7 : $i + 1; } $verifier += $numbers[$length - $i] * $multiplier; } $verifier = 11 - ($verifier % 11); if ($verifier >= 10) { $verifier = 0; } return $verifier; }