根据网卡(eth0, eth1)获得对应的IP地址

int get_interface_addr(char *eth, char *ipaddr)
{
int sock_fd;
struct  sockaddr_in my_addr;
struct ifreq ifr;

if ((sock_fd = socket(PF_INET, SOCK_DGRAM, 0)) == -1) {
perror("socket");
return RET_FAILED;
}

strncpy(ifr.ifr_name, eth, IF_NAMESIZE);
ifr.ifr_name[IFNAMSIZ-1]='/0';

if (ioctl(sock_fd, SIOCGIFADDR, &ifr) < 0) {
DBGPRN(":No Such Device %s/n",eth);
return RET_FAILED;
}

memcpy(&my_addr, &ifr.ifr_addr, sizeof(my_addr));
strcpy(ipaddr, inet_ntoa(my_addr.sin_addr));
close(sock_fd);
return RET_SUCCESS;
}