Ubuntu Manpages

CheckDigits::M11_008

compute check digits for VAT Registration Number (DK)

  use Algorithm::CheckDigits;
  $ustid = CheckDigits('ustid_dk');
  if ($ustid->is_valid('13585628')) {
        # do something
  }
  $cn = $ustid->complete('1358562');
  # $cn = '13585628'
  $cd = $ustid->checkdigit('13585628');
  # $cd = '8'
  $bn = $ustid->basenumber('13585628');
  # $bn = '1358562';

ALGORITHM

1.
Beginning left every digit is weighted with 2, 7, 6, 5, 4, 3, 2, 1
2.
The weighted digits are added.
3.
The sum from step 2 is taken modulo 11.
4.
The number is valid if the sum from step 3 is zero (0).

METHODS

Returns true only if $number consists solely of numbers and hyphens and the two digits in the middle are valid check digits according to the algorithm given above.

Returns false otherwise,

The check digit for $number is computed and inserted into the middle of $number.

Returns the complete number with check digit or '' if $number does not consist solely of digits, hyphens and spaces.

Returns the basenumber of $number if $number has a valid check digit.

Return '' otherwise.

Returns '' if $number is valid.

Return undef otherwise.

EXPORT

None by default.

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

perl, CheckDigits, www.pruefziffernberechnung.de,