#include <sys/ioctl.h>

include <net/if.h>
include <unistd.h>
include <netinet/in.h>
include <string.h>
int main()
{
    struct ifreq ifr;
    struct ifconf ifc;
    char buf[2048];
    int success = 0;

int sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
if (sock == -1) {
    printf("socket error\n");
    return -1;
}

ifc.ifc_len = sizeof(buf);
ifc.ifc_buf = buf;
if (ioctl(sock, SIOCGIFCONF, &ifc) == -1) {
    printf("ioctl error\n");
    return -1;
}

struct ifreq* it = ifc.ifc_req;
const struct ifreq* const end = it + (ifc.ifc_len / sizeof(struct ifreq));
char szMac[64];
int count = 0;
for (; it != end; ++it) {
    strcpy(ifr.ifr_name, it->ifr_name);
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        if (! (ifr.ifr_flags & IFF_LOOPBACK)) { // don't count loopback
            if (ioctl(sock, SIOCGIFHWADDR, &ifr) == 0) {
                count ++ ;
                unsigned char * ptr ;
                ptr = (unsigned char  *)&ifr.ifr_ifru.ifru_hwaddr.sa_data[0];
                snprintf(szMac,64,"%02X:%02X:%02X:%02X:%02X:%02X",*ptr,*(ptr+1),*(ptr+2),*(ptr+3),*(ptr+4),*(ptr+5));
                printf("%d,Interface name : %s , Mac address : %s \n",count,ifr.ifr_name,szMac);
            }
        }
    }else{
        printf("get mac info error\n");
        return -1;
    }
}

}
 </pre> 

 執行結果如下
1,Interface name : eth0 , Mac address : 90:B1:1D:87:13:75
2,Interface name : virtac , Mac address : 52:54:00:96:E0:BF
3,Interface name : map , Mac address : 52:54:00:F2:FE:9C
4,Interface name : poi , Mac address : 52:54:00:1B:97:82
5,Interface name : vnet1 , Mac address : 52:54:00:05:14:E3