NAME

       CheckDigits::M23_001 - compute check digits for DNI (ES)

SYNOPSIS

         use Algorithm::CheckDigits;

         $dni = CheckDigits('dni_es');

         if ($dni->is_valid('54362315K')) {
               # do something
         }

         $cn = $dni->complete('54362315');
         # $cn = '54362315K'

         $cd = $dni->checkdigit('54362315K');
         # $cd = 'K'

         $bn = $dni->basenumber('54362315K');
         # $bn = '54362315'

DESCRIPTION

   ALGORITHM
       1.  The checkdigit is the whole number taken modulo 23 and coded according to a keytable.

   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.