Programme de conversion

#include <iostream>

#include <string>

// Convert string of chars to its representative string of hex numbers

void stream2hex(const std::string str, std::string& hexstr, bool capital = false)

{

hexstr.resize(str.size() * 2);

const size_t a = capital ? 'A' - 1 : 'a' - 1;

for (size_t i = 0, c = str[0] & 0xFF; i < hexstr.size(); c = str[i / 2] & 0xFF)

{

hexstr[i++] = c > 0x9F ? (c / 16 - 9) | a : c / 16 | '0';

hexstr[i++] = (c & 0xF) > 9 ? (c % 16 - 9) | a : c % 16 | '0';

}

// Convert string of hex numbers to its equivalent char-stream

void hex2stream(const std::string hexstr, std::string& str)

{

str.resize((hexstr.size() + 1) / 2);

for (size_t i = 0, j = 0; i < str.size(); i++, j++)

{

str[i] = (hexstr[j] & '@' ? hexstr[j] + 9 : hexstr[j]) << 4, j++;

str[i] |= (hexstr[j] & '@' ? hexstr[j] + 9 : hexstr[j]) & 0xF;

}

int main()

{

std::string s = "Hello World!";

std::cout << "original string: " << s << '\n';

stream2hex(s, s);

std::cout << "hex format: " << s << '\n';

hex2stream(s, s);

std::cout << "original one: " << s << '\n';

}