bitdiff.cc

#include <iostream>
#include <fstream>
#include <vector>
#include <sstream>
#include <iterator>

constexpr const char *text_color_reset = "\e[0m";
constexpr const char *text_color_red = "\e[31m";

template<typename T>
size_t largest_container(const T &conts) {
	size_t s = 0;
	for(auto &cont : conts)
		s = s < cont.size() ? cont.size() : s;
	return s;
}

std::vector<uint8_t> compute_difference_mask(std::vector<std::vector<uint8_t>> v) {
	size_t output_size = largest_container(v);
	std::vector<uint8_t> output{};
	output.resize(output_size);

	for(size_t i = 0; i < output_size; i++) {
		bool cont = true;

		uint8_t a = 0xFF;
		uint8_t b = 0xFF;

		for (auto &c : v) {
			if (i >= c.size()) {
				cont = false;
				output[i] = 0xFF;
				break;
			}

			a &= c[i];
			b &= ~c[i];
		}

		if (!cont)
			continue;

		output[i] = ~(a | b);
	}

	return output;
}

void format_byte_as_bits(std::ostringstream &out, uint8_t byte, uint8_t diff_mask) {
	for (ssize_t i = 7; i >= 0; i--) {
		int bit = (byte >> i) & 1;

		if (diff_mask & (1 << i))
			out << text_color_red;

		out << bit;

		if (diff_mask & (1 << i))
			out << text_color_reset;
	}
}

std::string format_vector_as_bits(std::vector<uint8_t> bytes, std::vector<uint8_t> diff_mask = {}) {
	std::ostringstream out{};

	for (size_t i = 0; i < bytes.size(); i++) {
		uint8_t byte = bytes[i];
		uint8_t diff = i < diff_mask.size() ? diff_mask[i] : 0;
		format_byte_as_bits(out, byte, diff);
		out << " ";
	}

	return out.str();
}

std::vector<std::vector<uint8_t>> load_file(const std::string &path) {
	std::vector<std::vector<uint8_t>> out{};
	std::string line;
	std::ifstream file{path};

	while(std::getline(file, line)) {
		std::vector<uint8_t> bytes{};

		std::istringstream in{line};
		std::vector<std::string> toks((std::istream_iterator<std::string>(in)),
					std::istream_iterator<std::string>());

		for (auto &tok : toks) {
			bytes.push_back(std::stoi(tok, nullptr, 16));
		}
		out.push_back(bytes);
	}

	return out;
}

int main(int argc, char **argv) {
	if (argc < 2) {
		std::cerr << "usage: <file1> [file2] ... [filen]\n";
		return 1;
	}

	for (int i = 1; i < argc; i++) {
		auto values = load_file(argv[i]);

		std::vector<uint8_t> diff = compute_difference_mask(values);

		for(size_t i = 0; i < values.size(); i++) {
			std::cout << (i + 1) << ":\t" << format_vector_as_bits(values[i], diff) << "\n";
		}

		std::cout << "diff:\t" << format_vector_as_bits(diff) << "\n";

		if (i != argc - 1)
			std::cout << " --------------------------- \n";
	}
}