CheckDigits::MXX_002(3User Contributed Perl DocumentatiCheckDigits::MXX_002(3)NAME
CheckDigits::MXX_002 - compute check digits for CAS
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, <mathias@weidner.in-bad-schmiedeberg.de>
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)
SEE ALSO
perl, CheckDigits, www.pruefziffernberechnung.de, www.cas.org
http://www.cas.org/expertise/cascontent/registry/checkdig.html
perl v5.14.1 2009-11-20 CheckDigits::MXX_002(3)