Provided by: libalgorithm-checkdigits-perl_0.50-1_all

**NAME**

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

**SYNOPSIS**

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'

**DESCRIPTION**

ALGORITHM1. 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.METHODSis_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.EXPORTNone by default.

**AUTHOR**

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

**SEE** **ALSO**

perl, CheckDigits,www.pruefziffernberechnung.de.