# Algorithm::CheckDigits::M10_009.3pm

Langue: en

Autres versions - même langue

Version: 2008-05-17 (debian - 07/07/09)

Section: 3 (Bibliothèques de fonctions)

# Sommaire

## NAME

CheckDigits::M10_009 - compute check digits for Betriebsnummer (DE)

## SYNOPSIS

```   use Algorithm::CheckDigits;

\$betrnr = CheckDigits('betriebsnummer');

if (\$betrnr->is_valid('73282932000074')) {
# do something
}

\$cn = \$betrnr->complete('7328293200007');
# \$cn = '73282932000074'

\$cd = \$betrnr->checkdigit('73282932000074');
# \$cd = '4'

\$bn = \$betrnr->basenumber('73282932000074');
# \$bn = '7328293200007'

```

## DESCRIPTION

### ALGORITHM

1.
Beginning left all numbers are weighted alternatively 1 and 2.
2.
The total of the digits of all products is computed.
3.
The sum of step 3 ist taken modulo 10.
4.
The check digit is the difference between 10 and the number from step 3 taken modulo 10.

HINT: The last digit of the 'Betriebsnummer' may be the check digit or the last digit of the sum of the constant 5 and the check digit.

### 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.

None by default.

## AUTHOR

Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>

## SEE ALSO

perl, CheckDigits, www.pruefziffernberechnung.de. www.dsi.cnrs.fr/bureau_qualite/admindonnees/documents/siren.pdf