# FreeBSD Manual Pages

```Algorithm::CheckDigitsUser0Contributed Perl Algorithm::CheckDigits::M10_006(3)

NAME
CheckDigits::M10_006 - compute check digits for Rentenversicherung (DE)

SYNOPSIS
use Algorithm::CheckDigits;

\$rv = CheckDigits('rentenversicherung');

if (\$rv->is_valid('65180539W001')) {
# do something
}

\$cn = \$rv->complete('65180539W00');
# \$cn = '65180539W001'

\$cd = \$rv->checkdigit('65180539W001');
# \$cd = '1'

\$bn = \$rv->basenumber('65180539W001');
# \$bn = '65180539W00'

DESCRIPTION
ALGORITHM
1.  The letter is replaced with a two-figure number appropriate to the
position of the letter in the german	alphabet.

2.  Beginning left all numbers are weighted with
2,1,2,5,7,1,2,1,2,1,2,1.

3.  The the total of the	digits of all products is computed.

4.  The check digit is sum from step 3 taken modulo 10.

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>"