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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

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,

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.

Returns the basenumber of $number if $number has a valid check digit.

Return '' otherwise.

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.

2021-11-19 perl v5.32.1