DOKK / manpages / debian 11 / libalgorithm-checkdigits-perl / Algorithm::CheckDigits::M11_003.3pm.en
CheckDigits::M11_003(3pm) User Contributed Perl Documentation CheckDigits::M11_003(3pm)

CheckDigits::M11_003 - compute check digits for PKZ (GDR)

  use Algorithm::CheckDigits;
  $pkz = CheckDigits('pkz');
  if ($pkz->is_valid('150765400354')) {
        # do something
  }
  $cn = $pkz->complete('15076540035');
  # $cn = '150765400354'
  $cd = $pkz->checkdigit('150765400354');
  # $cd = '4'
  $bn = $pkz->basenumber('150765400354');
  # $bn = '150765400354'

ALGORITHM

1.
The checkdigit is set to 0.
2.
From right to left the digits are weighted (multiplied) with 2,4,8,5,10,9,7,3,6,1,2,4.
3.
The products are added.
4.
The sum of step 3 is taken modulo 11.
5.
The value of step 4 is added to a multiple (0..9) of the weight of the checkdigit (2).
6.
The sum of step 5 is taken modulo 11.
7.
The checkdigit is the multiple of the weight of the checkdigit where the value of step 6 equals 10.
8.
If there can't be reached a value of 10 in step 6, the number cannot be taken as a PKZ.

To validate a PKZ apply steps 2 to 4 to the complete number.

METHODS

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,

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.

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

Return '' otherwise.

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

Return '' otherwise.

EXPORT

None by default.

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

perl, CheckDigits, www.pruefziffernberechnung.de.

2021-01-03 perl v5.32.0