CheckDigits::M16_001(3User Contributed Perl DocumentatiCheckDigits::M16_001(3)NAME
CheckDigits::M16_001 - compute check digits for ISAN
SYNOPSIS
use Algorithm::CheckDigits;
$isan = CheckDigits('isan');
if ($isan->is_valid('123A567B8912E01A')) {
# do something
}
$cn = $isan->complete('123A567B8912E01');
# $cn = '123A567B8912E01A'
$cd = $isan->checkdigit('123A567B8912E01A');
# $cd = '4'
$bn = $isan->basenumber('123A567B8912E01A');
# $bn = '123A567B8912E01'
DESCRIPTION
ALGORITHM
1. "a(1) = 16"
"b(i) = a(i) % 17 +d(i)", where d(i) is the decimal value of the
hexdigit at position i.
"c(i) = b(i) % 16"
"a(i) = c(i-1) * 2", for i greater than 1
2. Beginning left for each i = 1..16, "a", "b", "c" are computed.
3. The check digit is the value for "d(16)" where "c(16)" equals 1.
4. The check digit is appended as hexadecimal value to the number.
METHODS
is_valid($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>
SEE ALSO
perl, CheckDigits, www.pruefziffernberechnung.de.
perl v5.14.1 2009-11-20 CheckDigits::M16_001(3)