#include <stdio.h>

 #include <string.h>

 #include <sys/types.h>

 #include <sys/socket.h>

 #include <sys/ioctl.h>

 #include <netinet/in.h>

 #include <net/if.h>

 int

 main()

 {

  int fd;

  struct ifreq ifr;

  fd = socket(AF_INET, SOCK_DGRAM, );

  ifr.ifr_addr.sa_family = AF_INET;

  strncpy(ifr.ifr_name, "eth0", IFNAMSIZ-);

  ioctl(fd, SIOCGIFHWADDR, &ifr);

  close(fd);

  printf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x\n",

          (unsigned char)ifr.ifr_hwaddr.sa_data[],

          (unsigned char)ifr.ifr_hwaddr.sa_data[],

          (unsigned char)ifr.ifr_hwaddr.sa_data[],

          (unsigned char)ifr.ifr_hwaddr.sa_data[],

          (unsigned char)ifr.ifr_hwaddr.sa_data[],

          (unsigned char)ifr.ifr_hwaddr.sa_data[]);

  return ;

 }