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**

**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**
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__.