NAME

CheckDigits::MBase_002 - compute check digits for blood bags (DE), BZÜ (DE), VAT Registration Number (DE)

SYNOPSIS

  use Algorithm::CheckDigits;

  $bb = CheckDigits('blutbeutel');

  if ($bb->is_valid('2761011234567893')) {
	# do something
  }

  $cn = $bb->complete('276101123456789');
  # $cn = '2761011234567893'

  $cd = $bb->checkdigit('2761011234567893');
  # $cd = '3'

  $bn = $bb->basenumber('2761011234567893');
  # $bn = '276101123456789';
  

DESCRIPTION

ALGORITHM

1. Start with values P = 10, S = 0.

2. Beginning left you do the following for all digits

   1. S = (P + digit) modulo 10

   2. If S is 0 then S = 10.

   3. P = (2 * S) modulo 11

3. The check digit is (11 - P) modulo 10.

METHODS

is_valid($number)

Returns true only if $number consists solely of numbers and the last digit is a valid check digit according to the algorithm given above.

Returns false otherwise,

complete($number)

The check digit for $number is computed and concatenated to the end of $number.

Returns the complete number with check digit or '' if $number does not consist solely of digits and spaces.

basenumber($number)

Returns the basenumber of $number if $number has a valid check digit.

Return '' otherwise.

checkdigit($number)

Returns the checkdigit of $number if $number has a valid check digit.

Return '' otherwise.

EXPORT

None by default.

AUTHOR

Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>

SEE ALSO

perl, CheckDigits, www.pruefziffernberechnung.de, www.eurocode.org.