I have a string say :
string abc = "1023456789ABCD"
I want to convert it into a byte array like :
byte[0] = 0x10;
byte[1] = 0x23;
byte[2] = 0x45;
----
and so on
I checked some of the posts here but couldn't find the proper solution. Any help will be appreciated. Thanks in Advance.
See it Live on Coliru
#include <string>
#include <cassert>
template <typename Out>
void hex2bin(std::string const& s, Out out) {
assert(s.length() % 2 == 0);
std::string extract;
for (std::string::const_iterator pos = s.begin(); pos<s.end(); pos += 2)
{
extract.assign(pos, pos+2);
*out++ = std::stoi(extract, nullptr, 16);
}
}
#include <iostream>
#include <vector>
int main()
{
std::vector<unsigned char> v;
hex2bin("1023456789ABCD", back_inserter(v));
for (auto byte : v)
std::cout << std::hex << (int) byte << "\n";
}
Outputs
10
23
45
67
89
ab
cd
when you say 'byte' it looks like you're meaning each character represented in hexidecimal.
in that case you could simply use string.c_str(), as this is just a c-style string (char*).
byte[2] = 0x45
is the same as
byte[2] = 69; //this is 0x45 in decimal
you could assign the output of string.c_str() to another char* if you wanted to store the array seperately.
c_str() doesn't convert anything. It certainly won't turn the example input into the example output.