Convert string Mac address to byte-array

Sorry for necroposting, but just to help others who may still be searching for the answer, there is a standard C way that still can be used in C++ without any reinvention of the wheel. Just man ether_aton or click here.

This'll work. You've tagged this as C++ so I've scrupulously avoided the shorter solution that's possible using the sscanf C method. using namespace std is used here only to shorten the quoted code.

#include <iostream>
#include <sstream>

main() {

  unsigned char octets[6];
  unsigned int value;
  char ignore;

  using namespace std;

  istringstream iss("10:10:0F:A0:01:00",istringstream::in);

  iss >> hex;

  for(int i=0;i<5;i++) {
    iss >> value >> ignore;
    octets[i]=value;
  }
  iss >> value;
  octets[5]=value;

  // validate

  for(int i=0;i<sizeof(octets)/sizeof(octets[0]);i++)
    cout << hex << static_cast<unsigned int>(octets[i]) << " ";

  cout << endl;
}

I know that this is old, but I've got a similar routine for Bluetooth addresses. I added a regex filter to make sure the text is the correct format before I parse it.

The reverse order of bytes in this was important because it matches what's produced by the function in the Bluetooth library: int str2ba(const char *str, bdaddr_t *ba);

My new Bluetooth code talks to Bluetooth using an alternate method, but I wanted to keep the internal structure of the Bluetooth address matching.

#include <iomanip>
#include <iostream>
#include <regex>

#ifndef bdaddr_t
/* BD Address */
typedef struct {
    uint8_t b[6];
} __attribute__((packed)) bdaddr_t;
#endif // !bdaddr_t

const std::regex BluetoothAddressRegex("((([[:xdigit:]]{2}:){5}))[[:xdigit:]]{2}");

bdaddr_t string2ba(const std::string& TheBlueToothAddressString)
{ 
    bdaddr_t TheBlueToothAddress({ 0 });
    if (std::regex_match(TheBlueToothAddressString, BluetoothAddressRegex))
    {
        std::stringstream ss(TheBlueToothAddressString);
        std::string byteString;
        int index(5);
        // Because I've verified the string format with regex I can safely run this loop knowing it'll get 6 bytes
        while (std::getline(ss, byteString, ':'))
            TheBlueToothAddress.b[index--] = std::stoi(byteString, nullptr, 16);
    }
    return(TheBlueToothAddress); 
}