Re: [cool hack] Credit Card validator

Let me publish it in general bits.
Why didn't you write it in plperl?

elein

On Thu, Oct 30, 2003 at 01:17:42PM -0800, David Fetter wrote:
> Kind people,
>
> I know it's not the cleanest or efficientest, but I've ported part of
> Business::CreditCard into PL/PgSQL. Assuming it passes muster, where
> should I put it? Is there a CPAN-type thingy for PL/PgSQL? Should
> there be?
>
> Cheers,
> D
>
> CREATE OR REPLACE FUNCTION cc_check (VARCHAR) RETURNS BOOLEAN AS '
> DECLARE
> cc_num ALIAS FOR $1;
> i INTEGER;
> d VARCHAR;
> weight INTEGER;
> checksum INTEGER := 0;
> oddness INTEGER;
> num INTEGER;
> tempstring VARCHAR;
> BEGIN
> -- Strip out non-digits. Oh, for an s/// construct! :)
> tempstring := '''';
> FOR i IN 1 .. length(cc_num)
> LOOP
> d := SUBSTRING(cc_num, i, 1);
> IF d ~ ''[0-9]''
> THEN
> tempstring := tempstring || d;
> END IF;
> END LOOP;
> -- Check length for reasonableness.
> IF (length(tempstring) < 13)
> THEN
> RAISE NOTICE ''% is too short to be a credit card number.'', cc_num;
> RETURN FALSE;
> END IF;
> -- Do a Luhn checksum.
> oddness := length(tempstring) % 2;
> FOR i IN 1 .. length(tempstring)
> LOOP
> num := SUBSTRING(tempstring, i, 1)::integer;
> IF (oddness = 0 AND i % 2 = 1)
> THEN
> num := num * 2;
> ELSIF (oddness = 1 AND i%2 = 0)
> THEN
> num := num * 2;
> END IF;
> IF num > 9
> THEN
> num := num - 9;
> END IF;
> checksum := checksum + num;
> END LOOP;
> IF checksum % 10 <> 0
> THEN
> RAISE NOTICE ''% does not have a valid checksum.'', cc_num;
> RETURN FALSE;
> END IF;
> IF tempstring ~ ''^3[47][0-9]{13}$''
> THEN
> RAISE NOTICE ''% is an American Express card.'', cc_num;
> ELSIF tempstring ~ ''^4[0-9]{12}([0-9]{3})?$''
> THEN
> RAISE NOTICE ''% is a VISA card.'', cc_num;
> ELSIF tempstring ~ ''^5[1-5][0-9]{14}$''
> THEN
> RAISE NOTICE ''% is a MasterCard.'', cc_num;
> ELSIF tempstring ~ ''^6011[0-9]{12}$''
> THEN
> RAISE NOTICE ''% is a Discover card.'', cc_num;
> ELSIF tempstring ~ ''^3(0[0-5]|[68][0-9])[0-9]{11}$''
> THEN
> RAISE NOTICE ''% is a Diners Club/Carte Blanche.'', cc_num;
> ELSIF tempstring ~ ''^2(014|149)\d{11}$''
> THEN
> RAISE NOTICE ''% is an enRoute card.'', cc_num;
> ELSIF tempstring ~ ''^(3\d{4}|2131|1800)\d{11}$''
> THEN
> RAISE NOTICE ''% is a JCB card.'', cc_num;
> ELSIF tempstring ~ ''^56(10\d\d|022[1-5])\d{10}$''
> THEN
> RAISE NOTICE ''% is a BankCard.'', cc_num;
> END IF;
> RETURN TRUE;
> END;
> ' LANGUAGE 'plpgsql';
>
> --
> David Fetter david(at)fetter(dot)org http://fetter.org/
> phone: +1 510 893 6100 cell: +1 415 235 3778