1CheckDigits::M16_001(3)User Contributed Perl DocumentatioCnheckDigits::M16_001(3)
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6 CheckDigits::M16_001 - compute check digits for ISAN
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9 use Algorithm::CheckDigits;
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11 $isan = CheckDigits('isan');
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13 if ($isan->is_valid('123A567B8912E01A')) {
14 # do something
15 }
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17 $cn = $isan->complete('123A567B8912E01');
18 # $cn = '123A567B8912E01A'
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20 $cd = $isan->checkdigit('123A567B8912E01A');
21 # $cd = '4'
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23 $bn = $isan->basenumber('123A567B8912E01A');
24 # $bn = '123A567B8912E01'
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27 ALGORITHM
28 1. "a(1) = 16"
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30 "b(i) = a(i) % 17 +d(i)", where d(i) is the decimal value of the
31 hexdigit at position i.
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33 "c(i) = b(i) % 16"
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35 "a(i) = c(i-1) * 2", for i greater than 1
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37 2. Beginning left for each i = 1..16, "a", "b", "c" are computed.
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39 3. The check digit is the value for "d(16)" where "c(16)" equals 1.
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41 4. The check digit is appended as hexadecimal value to the number.
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43 METHODS
44 is_valid($number)
45 Returns true only if $number consists solely of numbers and the
46 last digit is a valid check digit according to the algorithm given
47 above.
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49 Returns false otherwise,
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51 complete($number)
52 The check digit for $number is computed and concatenated to the end
53 of $number.
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55 Returns the complete number with check digit or '' if $number does
56 not consist solely of digits and spaces.
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58 basenumber($number)
59 Returns the basenumber of $number if $number has a valid check
60 digit.
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62 Return '' otherwise.
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64 checkdigit($number)
65 Returns the checkdigit of $number if $number has a valid check
66 digit.
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68 Return '' otherwise.
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70 EXPORT
71 None by default.
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74 Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>
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77 perl, CheckDigits, www.pruefziffernberechnung.de.
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81perl v5.12.1 2009-11-20 CheckDigits::M16_001(3)