A howl on the wind…

//tinodidriksen.com/uploads/code/cpp/string-to-hex.cpp

#include <string>
#include <sstream>
#include <iostream>
#include <iomanip>

int main() {
    std::string str("abcABC123\xff\x01");
    std::stringstream ss;
    for (size_t i=0 ; i<str.length() ; ++i) {
        ss << std::setw(2) << std::setfill('0')
            << std::hex << (int(str[i])&0xFF);
    }
    std::cout << ss.str();
}