NAME

CheckDigits::M10_009 - compute check digits for Betriebsnummer (DE)

SYNOPSIS

  use Algorithm::CheckDigits;

  $betrnr = CheckDigits('betriebsnummer');

  if ($betrnr->is_valid('73282932000074')) {
	# do something
  }

  $cn = $betrnr->complete('7328293200007');
  # $cn = '73282932000074'

  $cd = $betrnr->checkdigit('73282932000074');
  # $cd = '4'

  $bn = $betrnr->basenumber('73282932000074');
  # $bn = '7328293200007'
  

DESCRIPTION

ALGORITHM

1. Beginning left all numbers are weighted alternatively 1 and 2.

2. The total of the digits of all products is computed.

3. The sum of step 3 ist taken modulo 10.

4. The check digit is the difference between 10 and the number from step 3 taken modulo 10.

   HINT: The last digit of the 'Betriebsnummer' may be the check digit or the last digit of the sum of the constant 5 and the check digit.

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, <mamawe@cpan.org>

SEE ALSO

perl, CheckDigits, www.pruefziffernberechnung.de. www.dsi.cnrs.fr/bureau_qualite/admindonnees/documents/siren.pdf