Compute check digits for ec-no, einecs, elincs
use Algorithm::CheckDigits; $ecno = CheckDigits('ecno'); if ($ecno->is_valid('200-236-6')) { # do something } $cn = $ecno->complete('200-236-'); # $cn = '200-236-6' $cd = $ecno->checkdigit('200-236-6'); # $cd = '6' $bn = $ecno->basenumber('200-236-6'); # $bn = '200-236-'
From left to right all digits are multiplied with their position in the sequence.
The sum of all products is computed.
The sum of step 2 is taken modulo 11. The checkdigit is the last digit of the result.
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,
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.
Returns the basenumber of $number if $number has a valid check digit. Return '' otherwise.
Returns the checkdigit of $number if $number has a valid check digit. Return '' otherwise.
None by default.
Mathias Weidner, <[email protected]>
perl, CheckDigits, http://en.wikipedia.org/wiki/EC-No.