SIN.pl

#!/usr/bin/perl -w

# [06:37:08:teuk@ramses:~/src/perl] ./SIN.pl 046454286
# 0 currentControl=0
# 1 currentControl=8
# 2 currentControl=6
# 3 currentControl=8
# 4 currentControl=5
# 5 currentControl=8
# 6 currentControl=2
# 7 currentControl=16
# 8 currentControl=6
# checksum=50SIN 046454286 is valid, 50 is divisible by 10

my $SIN = $ARGV[0];

unless ( defined($SIN) && ($SIN =~ /[0-9]{9}/ )) {
    print "SIN Invalid\n";
    print "SIN.pl <SIN>\n";
    exit 1;
}

my @controls;
for (my $i=0;$i<9;$i++) {
    my $currentControl = substr($SIN,$i,1);
    if ( $i % 2 ) {
        $currentControl*=2;
    }
    print "$i currentControl=$currentControl\n";
    if ($currentControl > 9) {
        $currentControl = int(substr($currentControl,0,1)) + int(substr($currentControl,1,1));
    }
    push @controls,$currentControl;
}

my $checksum = 0;
for (my $i=0;$i<9;$i++) {
    $checksum+=$controls[$i];
}

print "checksum=$checksum";
if ( $checksum % 10 ) {
    print "SIN $SIN is invalid, $checksum is not divisible by 10\n";
}
else {
    print "SIN $SIN is valid, $checksum is divisible by 10\n";
}