多网卡存在情况下获取指定网卡的MAC地址

void get_mac(Mac_Address &mac_address)
{
int fd = -1;
struct ifreq buf;
snprintf(mac_address,sizeof(mac_address),"00:00:00:00:00:00");
if((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
{
return;
}
//wlan0代表网卡的名字
strncpy(buf.ifr_ifrn.ifrn_name,"wlan0",sizeof(buf.ifr_ifrn.ifrn_name)-1);
if((ioctl(fd, SIOCGIFHWADDR, &buf)) != -1)
{
snprintf(mac_address, sizeof(), "%02x:%02x:%02x:%02x:%02x:%02x", buf.ifr_hwaddr.sa_data[0],buf.ifr_hwaddr.sa_data[1],
buf.ifr_hwaddr.sa_data[2], buf.ifr_hwaddr.sa_data[3],
buf.ifr_hwaddr.sa_data[4]), buf.ifr_hwaddr.sa_data[5])
}
close(fd);
return;
}