在linux下 获取本机MAC地址的函数

//获取本机MAC地址函数QString GetLocalMac()
{
int sock_mac;

struct ifreq ifr_mac;
char mac_addr[30];

sock_mac = socket( AF_INET, SOCK_STREAM, 0 );
if( sock_mac == -1)
{
perror("create socket falise...mac\n");
return "";
}

memset(&ifr_mac,0,sizeof(ifr_mac));
strncpy(ifr_mac.ifr_name, "eth0", sizeof(ifr_mac.ifr_name)-1);
if( (ioctl( sock_mac, SIOCGIFHWADDR, &ifr_mac)) < 0)
{
printf("mac ioctl error\n");
return "";
}

sprintf(mac_addr,"%02x%02x%02x%02x%02x%02x",
(unsigned char)ifr_mac.ifr_hwaddr.sa_data[0],
(unsigned char)ifr_mac.ifr_hwaddr.sa_data[1],
(unsigned char)ifr_mac.ifr_hwaddr.sa_data[2],
(unsigned char)ifr_mac.ifr_hwaddr.sa_data[3],
(unsigned char)ifr_mac.ifr_hwaddr.sa_data[4],
(unsigned char)ifr_mac.ifr_hwaddr.sa_data[5]);
printf("local mac:%s \n",mac_addr);

close( sock_mac );
return QString( mac_addr );
}