Algorithm::CheckDigits::M11_003 (3pm)

  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'

\s-1ALGORITHM\s0

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 \s-1PKZ\s0.

To validate a \s-1PKZ\s0 apply steps 2 to 4 to the complete number.

\s-1METHODS\s0

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.

\s-1EXPORT\s0

None by default.

Mathias Weidner, <[email protected]>

perl, CheckDigits, www.pruefziffernberechnung.de.