ubuntu用C++获取ip地址和mac地址

本文只能获取内网地址，后期会更新使其可以获取外网地址。

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#define ETH_NAME    "wlan0"  //如果要获取其他网卡的地址，将这个换为其他网卡名称，比如eth0

std::string get_ip();
void get_mac(char * mac_a);

int main()
{
    //ip
    std::string ip = get_ip();
    printf("ip: %s: ", ip.c_str());

    // mac address
    char * this_mac = new char[6];
    get_mac(this_mac);
    printf("mac: %02x:%02x:%02x:%02x:%02x:%02x\n", this_mac[0]&0xff, this_mac[1]&0xff, this_mac[2]&0xff, this_mac[3]&0xff, this_mac[4]&0xff, this_mac[5]&0xff);
    return 0;
}
std::string get_ip()
{
    int                 sockfd;
    struct sockaddr_in  sin;
    struct ifreq        ifr;

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd == -1) {
        perror("socket error");
        exit(1);
    }
    strncpy(ifr.ifr_name, ETH_NAME, IFNAMSIZ);      //Interface name

    if (ioctl(sockfd, SIOCGIFADDR, &ifr) == 0) {    //SIOCGIFADDR 获取interface address
        memcpy(&sin, &ifr.ifr_addr, sizeof(ifr.ifr_addr));
        return inet_ntoa(sin.sin_addr);
    }
}

void get_mac(char * mac_a)
{
    int                 sockfd;
    struct ifreq        ifr;

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd == -1) {
        perror("socket error");
        exit(1);
    }
    strncpy(ifr.ifr_name, ETH_NAME, IFNAMSIZ);      //Interface name

    if (ioctl(sockfd, SIOCGIFHWADDR, &ifr) == 0) {  //SIOCGIFHWADDR 获取hardware address
        memcpy(mac_a, ifr.ifr_hwaddr.sa_data, 6);
    }
}