#include "stdio.h"#include "stdlib.h"#include "string.h"#include "net/if.h"#include "arpa/inet.h"#include "linux/sockios.h"int main(int argc,char *argv[]){    struct sockaddr_in *addr;    struct ifreq ifr;    char*address;    int sockfd;    char *name = "eth0";    if( strlen(name) >= IFNAMSIZ)        printf("device name is error.\n"), exit(0);            strcpy( ifr.ifr_name, name);            sockfd = socket(AF_INET,SOCK_DGRAM,0);    //get inet addr    if( ioctl( sockfd, SIOCGIFADDR, &ifr) == -1)        printf("ioctl error.\n"), exit(0);    addr = (struct sockaddr_in *)&(ifr.ifr_addr);    address = inet_ntoa(addr->sin_addr);    printf("inet addr: %s\n",address);    //get Mask    if( ioctl( sockfd, SIOCGIFNETMASK, &ifr) == -1)        printf("ioctl error.\n"), exit(0);    addr = (struct sockaddr_in *)&ifr.ifr_addr;    address = inet_ntoa(addr->sin_addr);    printf("Mask: %s\n",address);    //get HWaddr     u_int8_t hd[6];    if(ioctl(sockfd, SIOCGIFHWADDR, &ifr) == -1)        printf("hwaddr error.\n"), exit(0);    memcpy( hd, ifr.ifr_hwaddr.sa_data, sizeof(hd));    printf("HWaddr: %02X:%02X:%02X:%02X:%02X:%02X\n", hd[0], hd[1], hd[2], hd[3], hd[4], hd[5]);        exit(0);}