How to convert a char array into string based hex-stream (ostringstream)

Question

Hi,

in C++ (on Linux with gcc) I'd like to put a byte array (vector<unsigned char>) to a ostringstream or a string.

I know that I can use sprintf but it doesn't seem to be the best way to use char* also.

btw: this link did not help

Edit: All answer work so far. But I did not meantion, that I'd like to convert the bytes/hex-values into their string representation, e.g., vector<..> = {0,1,2} -> string = "000102". Sorry for that missing but important detail

Answer 1

So you want to put the data of a vector of chars into a string? Easy:

string str;
str.resize(vec.size());
for (int n=0;n<vec.size();n++) {
  str[n] = vec[n];
}

Answer 2

From vector char arr to stl string:

std::string str(v.begin(), v.end());

From stl string to vector char array:

std::string str = "Hellow World!";
std::vector<unsigned char> v(str.begin(), str.end());

Answer 3

For setw include:

#include <iomanip>

This should put 01 in stream:

std::ostringstream oss;

unsigned char byte = 0x01;
oss << std::hex << std::setw(2) << std::setfill('0') << static_cast<int>(byte);