CheckDigits::M10_003(3pm)				User Contributed Perl Documentation				 CheckDigits::M10_003(3pm)

NAME

       CheckDigits::M10_003 - compute check digits for ISMN

SYNOPSIS

	 use Algorithm::CheckDigits;

	 $ismn = CheckDigits('ismn');

	 if ($ismn->is_valid('M-345-24680-5')) {
	       # do something
	 }

	 $cn = $ismn->complete('M-345-24680');
	 # $cn = 'M-345-24680-5'

	 $cd = $ismn->checkdigit('M-345-24680-5');
	 # $cd = '5'

	 $bn = $ismn->basenumber('M-345-24680-5');
	 # $bn = 'M-345-24680'

DESCRIPTION

   ALGORITHM
       1.  The 'M' as the first number gets the value 3.  Beginning left all numbers are weighted alternatively 3 and 1.

       2.  The sum 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.

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

SEE ALSO

       perl, CheckDigits, www.pruefziffernberechnung.de.

perl v5.10.0							    2008-05-17						 CheckDigits::M10_003(3pm)