NAME

       CheckDigits::MBase_002 - compute check digits for blood bags (DE), BZUe (DE), VAT
       Registration Number (DE)

SYNOPSIS

         use Algorithm::CheckDigits;

         $bb = CheckDigits('blutbeutel');

         if ($bb->is_valid('2761011234567893')) {
               # do something
         }

         $cn = $bb->complete('276101123456789');
         # $cn = '2761011234567893'

         $cd = $bb->checkdigit('2761011234567893');
         # $cd = '3'

         $bn = $bb->basenumber('2761011234567893');
         # $bn = '276101123456789';

DESCRIPTION

   ALGORITHM
       1.  Start with values P = 10, S = 0.

       2.  Beginning left you do the following for all digits

           1.  S = (P + digit) modulo 10

           2.  If S is 0 then S = 10.

           3.  P = (2 * S) modulo 11

       3.  The check digit is (11 - P) modulo 10.

   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.eurocode.org.