CheckDigits::MBase_003(3pm)				User Contributed Perl Documentation			       CheckDigits::MBase_003(3pm)

NAME

       CheckDigits::MBase_003 - compute check digits for SICI (Serial Item and Contribution Identifier)

SYNOPSIS

	 use Algorithm::CheckDigits;

	 $sici = CheckDigits('sici');

	 if ($sici->is_valid('0784-8679(20040308)6:<138>2.0.TX;2-H')) {
	       # do something
	 }

	 $cn = $sici->complete('0784-8679(20040308)6:<138>2.0.TX;2-');
	 # $cn = '0784-8679(20040308)6:<138>2.0.TX;2-H'

	 $cd = $sici->checkdigit('0784-8679(20040308)6:<138>2.0.TX;2-H');
	 # $cd = 'H'

	 $bn = $sici->basenumber('0784-8679(20040308)6:<138>2.0.TX;2-H');
	 # $bn = '0784-8679(20040308)6:<138>2.0.TX;2-';

DESCRIPTION

   ALGORITHM
       0   In the string describing the number all letters (A-Z) are replaced with numbers 10-35 accordingly. All other non-numbers are replaced
	   by 36.

       1   Beginning right the numbers at all odd positions are added.

       2   The sum from step 1 is multiplied by 3.

       3   Beginning right the numbers at all even positions are added.

       4   The sums from step 2 and 3 are added.

       5   The sum from step 4 is taken modulo 37.

       6   The checksum is 37 minus the sum from step 5 where numbers from 10 to 35 are represented by 'A' to 'Z' accordingly and 36 is
	   represented by '#'.

   METHODS
       is_valid($number)
	   Returns true only if $number consists solely of numbers and hyphens and the two digits in the middle are valid check digits according
	   to the algorithm given above.

	   Returns false otherwise,

       complete($number)
	   The check digit for $number is computed and inserted into the middle of $number.

	   Returns the complete number with check digit or '' if $number does not consist solely of digits, hyphens and spaces.

       basenumber($number)
	   Returns the basenumber of $number if $number has a valid check digit.

	   Return '' otherwise.

       checkdigit($number)
	   Returns the check digits of $number if $number has valid check digits.

	   Return '' otherwise.

   EXPORT
       None by default.

AUTHOR

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

SEE ALSO

       perl, CheckDigits, www.pruefziffernberechnung.de, http://sunsite.berkeley.edu/SICI/sici.pdf

perl v5.10.0							    2008-05-17					       CheckDigits::MBase_003(3pm)