# Inputs
my $input = "\x30\x05\x15";
my $packed = 1;

# Canonize input
if ($packed) {
   $input = unpack('N', substr(("\x00"x4).$input, -4));
}

# Do some work
#...

# Output results
printf("Results for 0x%X are %s\n", $input, "...");