NAME

CheckDigits::M11_008 - compute check digits method 11-008

SYNOPSIS

  use CheckDigits;

  $ustid = CheckDigits('ustid_fi');

  if ($ustid->is_valid('13669598')) {
	# do something
  }

  $cn = $ustid->complete('1366959');
  # $cn = '13669598'

  $cd = $ustid->checkdigit('13669598');
  # $cd = '8'

  $bn = $ustid->basenumber('13669598');
  # $bn = '1366959';
  

DESCRIPTION

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

is_valid($number)

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,

complete($number)

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.

basenumber($number)

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

Return '' otherwise.

checkdigit($number)

Returns '' if $number is valid.

Return undef otherwise.

EXPORT

None by default.

AUTHOR

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

SEE ALSO

perl, CheckDigits, www.pruefziffernberechnung.de,