CheckDigits::MBase_001User Contributed Perl DocumentaCheckDigits::MBase_001(3)NAMECheckDigits::MBase_001 - compute check digits for UPC (US)
SYNOPSIS
use Algorithm::CheckDigits;
$rv = CheckDigits('upc');
if ($rv->is_valid('012345678905')) {
# do something
}
$cn = $rv->complete('01234567890');
# $cn = '012345678905'
$cd = $rv->checkdigit('012345678905');
# $cd = '5'
$bn = $rv->basenumber('012345678905');
# $bn = '01234567890'
DESCRIPTION
ALGORITHM
1. Add all digits in odd-numbered positions.
2. Multiply the sum from step 1 with 3.
3. Add all digits in even-numbered positions.
4. Add the product from step 2 and the sum from step 3.
5. If the sum from step 4 is 0 modulo 10, the check digit is 0. Else
the check digit is 10 minus the sum from step 4 taken modulo 10.
METHODS
is_valid($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.
SEE ALSO
perl, CheckDigits, www.pruefziffernberechnung.de,
www.export911.com/e911/coding/upcChar.htm,
www.adams1.com/pub/russadam/upccode.html, http://www.upcdatabase.com.
perl v5.14.1 2009-11-20 CheckDigits::MBase_001(3)