decrypt.cpp

/*********************************************************
	  File Name: decrypt.cpp
	  Author: Abby Cin
	  Mail: abbytsing@gmail.com
	  Created Time: Sat 17 Dec 2016 04:02:01 PM CST
**********************************************************/

#include <iostream>
#include <fstream>
#include "crypto.h"

void cb(int magic, std::string &s)
{
	for (auto &x : s)
		x -= magic;
}

int main(int argc, char *argv[])
{
	if (argc != 3) {
		fprintf(stderr, "%s magic path\n", argv[0]);
		return 1;
	}
	int magic = 0;
	try {
		magic = std::stoi(argv[1]);
	}
	catch (const std::logic_error &e) {
		std::cerr << "Invalid magic number\n";
		return 1;
	}
	std::ifstream in(argv[2]);
	if (!in.is_open()) {
		std::cerr << "Can't open file: " << argv[2] << std::endl;
		return 1;
	}
	std::string s;
	char c = '\0';
	in.read(&c, 1);
	in.read(&c, 1);
	in.read(&c, 1);
	std::getline(in, s);
	in.close();
	Crypto crypto;
	auto res = crypto.decode(s, magic, cb);
	std::cout << res << std::endl;
}