CheckDigits::MXX_001 - compute check digits for german Personalausweis (pa_de) or ABA routing numbers (aba_rn)
use Algorithm::CheckDigits;
$pa = CheckDigits('pa_de');
if ($pa->is_valid('2406055684D<<6810203<0705109<6')) {
# do something
}
if ($pa->is_valid('2406055684') {
# do_something
}
$cn = $pa->complete('240605568_D<<681020_<070510_<_');
# $cn = '2406055684D<<6810203<0705109<6'
$cd = $pa->checkdigit('2406055684D<<6810203<0705109<6');
# $cd = '6'
$bn = $pa->basenumber('2406055684D<<6810203<0705109<6');
# $bn = '240605568_D<<681020_<070510_<_'
$aba = CheckDigits('aba_rn');
if ($aba->is_valid('789456124')) {
# do something
}
ALGORITHM
1. |
Beginning left all digits are weighted with 7,3,1,7,3,1,... for pa_de or 3,7,1,3,7,1,3,7,1 for aba_rn. |
||
2. |
The sum of those products is computed. |
||
3. |
For pa_de the checksum is the last digit of the sum from step 2 (modulo 10). |
For aba_rn the checksum is the difference of the sum from step 2 to the next multiple of 10.
4. |
For the german Personalausweis step 1 to 3 is performed for every part of the number and for all 3 parts including the particular checkdigit to compute the total checksum. |
If the number solely consists of digits, the checksum is just computed once according to algorithm given above.
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.
Mathias Weidner, "<mamawe AT cpan DOT org>"
Aaron W. West pointed me to a fault in the computing of the check digit. Jim Hickstein made me aware of the ABA routing numbers.
perl, CheckDigits, www.pruefziffernberechnung.de, http://answers.google.com/answers/threadview/id/43619.html, http://www.brainjar.com/js/validation/