NAME¶

CheckDigits::M11_017 - compute check digits for EC-No, EINECS, ELINCS

SYNOPSIS¶

  use Algorithm::CheckDigits;
  $ecno = CheckDigits('ecno');
  if ($ecno->is_valid('200-236-6')) {
        # do something
  }
  $cn = $ecno->complete('200-236-');
  # $cn = '200-236-6'
  $cd = $ecno->checkdigit('200-236-6');
  # $cd = '6'
  $bn = $ecno->basenumber('200-236-6');
  # $bn = '200-236-'

DESCRIPTION¶

ALGORITHM¶

1.

From left to right all digits are multiplied with their position in the sequence.

2.

The sum of all products is computed.

3.

The sum of step 2 is taken modulo 11.

 

The checkdigit is the last digit of the result.

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, http://en.wikipedia.org/wiki/EC-No.