table of contents
| Algorithm::CheckDigits::M16_001(3pm) | User Contributed Perl Documentation | Algorithm::CheckDigits::M16_001(3pm) |
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, "<mamawe@cpan.org>"
SEE ALSO¶
perl, CheckDigits, www.pruefziffernberechnung.de.
| 2021-11-17 | perl v5.40.0 |