SYNOPSIS
use Algorithm::CheckDigits;
$cas = CheckDigits('cas');
if ($cas->is_valid('1333-74-0')) {
# do something
}
$cn = $cas->complete('1333-74-');
# $cn = '1333-74-0'
$cd = $cas->checkdigit('1333-74-0');
# $cd = '0'
$bn = $cas->basenumber('1333-74-0');
# $bn = '1333-74-'
DESCRIPTION
ALGORITHM
- 1.
- Beginning right with the second digit all digits are weighted ascending starting with 1.
- 2.
- The sum of those products is computed.
- 3.
- The checksum is the last digit of the sum from step 2 (modulo 10).
METHODS
- is_valid($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.
EXPORT
None by default.AUTHOR
Mathias Weidner, <[email protected]>THANKS
Aaron W. West pointed me to a fault in the computing of the check digit.HERMIER Christophe made me aware that CAS is now assigning 10-digit CAS Registry Numbers (http://www.cas.org/newsevents/10digitrn.html)