validate JMBG

jmbg.pl

#!/usr/bin/perl

use warnings;
use strict;

sub valid_jmbg {
        my $jmbg = shift;
        return 0 unless $jmbg =~ /^\d{13}$/;
        my @c = split(//, $jmbg);
        my $S=0;
        for (my $i=0;$i<6;$i++){
                $S+= (7-$i)*($c[$i]+$c[6+$i]);
        }
        print "$jmbg ";
        my $checksum = 11-($S%11);
        if ( $checksum == $c[12] ) {
                print "OK\n";
        } else {
                print "ERROR [$checksum]\n";
        }
}

valid_jmbg($_) foreach @ARGV;

More information at: http://en.wikipedia.org/wiki/Unique_Master_Citizen_Number