hexadecimal division

[holandes777]

Lift the veil of ignorance from my eyes

I am trying to follow am LRC computation (Longitudinal CRC computation) and have hit a bump

# Calculating the exclusive or of "202005"
# V= X’32’ .XOR. X’30’ .XOR. X’32’ .XOR. X’30’ .XOR. X’30’ .XOR. X’35’
+ = X’05’

my $command = '202005';
print "$command length=" . length($command) . "\n";
my $result = substr($command,0,1);
for (my $i=1; $i<length($command); $i++) {
    my $c = substr($command,$i,1);
    print "$i) " . sprintf("%02X ", ord($result)) . " xor ". sprintf("
+%02X ", ord($c));
    $result = $result ^ $c;
    print " gives " . sprintf("%02X ", ord($result)) . "\n";
}
print sprintf("%02X ", ord($result))  . "\n";
if ( $result == "\x05" ) { print ":-)\n"; } else { print ":-(\n"; } 
print "====\n";

# THIS IS WHERE THE PROBLEM BEGINS:

# Divide by X’10:
# Y = INT ( X’05’ / X’10’ ) = X’00’

my $dividend = $result;
my $divisor = "\x10";
my $result2;
#$result2 = int($dividend/$divisor);
#print sprintf("%02X ", ord($result2))  . "\n";
# results in Illegal division by zero at kk.pl line 22.

# and this results in character zero, not NUL:
$result2 = int(ord($dividend)/ord($divisor));
print sprintf("%02X ", ord($result2))  . "\n";

What concept did I miss? Thank you.

It has been pointed out I was noyt clear as to what I needed, and it is true! So allow me to clarify:

The result of the xor-ing is correct according to the API doc: they expect X'05' and if you run the code we have a display of 05 which is 0x05. It is the next step, where we divide this 0x05 result by X'10' (0x10). The code says:<\p> $result2 = int($dividend/$divisor);

what I expect is 5/16 converted to an int which is the NUL characted (0x00) which the API show as X'00'. The result I AM getting is 30 (0x30 or the ascii charated zero). This is where I need your help, on the last statement.