Linux下获取MAC地址

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/if_ether.h>
#include <string.h>
#include <netinet/ether.h>
#include<unistd.h>
int main(int argc, char **argv)
{
printf("helloworld\n");
int nSocket;
struct ifreq struReq;
nSocket = socket(PF_INET,SOCK_STREAM,0);
memset(&struReq,0,sizeof(struReq));
if(argc < 2)
strncpy(struReq.ifr_name, "eth0", sizeof(struReq.ifr_name));
else
strncpy(struReq.ifr_name, argv[1], sizeof(struReq.ifr_name));
ioctl(nSocket,SIOCGIFHWADDR,&struReq);
fprintf(stderr, "%d-%s\n", __LINE__, strerror(errno));
printf("%s \n", ether_ntoa( (const ether_addr*)(struReq.ifr_ifru.ifru_hwaddr.sa_data)));
close(nSocket);

}
man reference
 http://linux.die.net/man/7/netdevice