Algorithm::CheckDigits::MXX_004 (3pm)

  use Algorithm::CheckDigits;

  $vat = CheckDigits('ustid_at');

  if ($vat->is_valid('U13585627')) {
        # do something
  }

  $cn = $vat->complete('U1358562');
  # $cn = 'U13585627'

  $cd = $vat->checkdigit('U13585627');
  # $cd = '7'

  $bn = $vat->basenumber('U13585627');
  # $bn = 'U1358562'

\s-1ALGORITHM\s0

1.

Beginning right all numbers before the check digit are weighted alternatively 1 and 2.

2.

The total of the digits of all products is computed and then subtracted from 96.

3.

The check digit is the sum of step 3 taken modulo 10.

\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.