# FreeBSD Manual Pages

```Algorithm::CheckDigitsUser3Contributed Perl Algorithm::CheckDigits::M43_001(3)

NAME
CheckDigits::M43_001 - compute check digits for Code-39

SYNOPSIS
use Algorithm::CheckDigits;

\$c39 =	CheckDigits('code_39');

if (\$c39->is_valid('AB-123K'))	{
# do something
}

\$cn = \$c39->complete('AB-123');
# \$cn = 'AB-123K'

\$cd = \$c39->checkdigit('AB-123K');
# \$cd = 'K'

\$bn = \$c39->basenumber('AB-123K');
# \$bn = 'AB-123'

DESCRIPTION
ALGORITHM
1.  After replacing all non numeric letters with	their respective
values, the sum of all numbers is computers

2.  The checkdigit is the sum from step 1 taken modulo 43.

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>"