LINUX C: 获取本地指定网卡的IP地址-白红宇

LINUX C: 获取本地指定网卡的IP地址

阅读量：6938 次

发布时间：2019-06-27

本文共 2546 字，大约阅读时间需要 8 分钟。

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               #define MAC_SIZE 18#define IP_SIZE 16// function declareint get_ip_by_domain(const char *domain, char *ip); // 根据域名获取ipint get_local_mac(const char *eth_inf, char *mac); // 获取本机macint get_local_ip(const char *eth_inf, char *ip); // 获取本机ip/****** main test **********/int main(void){ char ip[IP_SIZE]; char mac[MAC_SIZE]; const char *test_domain = "www.baidu.com"; const char *test_eth = "eth0"; get_ip_by_domain(test_domain, ip); printf("%s ip: %s\n", test_domain, ip); get_local_mac(test_eth, mac); printf("local %s mac: %s\n", test_eth, mac); get_local_ip(test_eth, ip); printf("local %s ip: %s\n", test_eth, ip); return 0;}// 根据域名获取ipint get_ip_by_domain(const char *domain, char *ip){ char **pptr; struct hostent *hptr; hptr = gethostbyname(domain); if(NULL == hptr) { printf("gethostbyname error for host:%s/n", domain); return -1; } for(pptr = hptr->h_addr_list ; *pptr != NULL; pptr++) { if (NULL != inet_ntop(hptr->h_addrtype, *pptr, ip, IP_SIZE) ) { return 0; // 只获取第一个 ip } } return -1;}// 获取本机macint get_local_mac(const char *eth_inf, char *mac){ struct ifreq ifr; int sd; bzero(&ifr, sizeof(struct ifreq)); if( (sd = socket(AF_INET, SOCK_STREAM, 0)) < 0) { printf("get %s mac address socket creat error\n", eth_inf); return -1; } strncpy(ifr.ifr_name, eth_inf, sizeof(ifr.ifr_name) - 1); if(ioctl(sd, SIOCGIFHWADDR, &ifr) < 0) { printf("get %s mac address error\n", eth_inf); close(sd); return -1; } snprintf(mac, MAC_SIZE, "%02x:%02x:%02x:%02x:%02x:%02x", (unsigned char)ifr.ifr_hwaddr.sa_data[0], (unsigned char)ifr.ifr_hwaddr.sa_data[1], (unsigned char)ifr.ifr_hwaddr.sa_data[2], (unsigned char)ifr.ifr_hwaddr.sa_data[3], (unsigned char)ifr.ifr_hwaddr.sa_data[4], (unsigned char)ifr.ifr_hwaddr.sa_data[5]); close(sd); return 0;}// 获取本机ipint get_local_ip(const char *eth_inf, char *ip){ int sd; struct sockaddr_in sin; struct ifreq ifr; sd = socket(AF_INET, SOCK_DGRAM, 0); if (-1 == sd) { printf("socket error: %s\n", strerror(errno)); return -1; } strncpy(ifr.ifr_name, eth_inf, IFNAMSIZ); ifr.ifr_name[IFNAMSIZ - 1] = 0; // if error: No such device if (ioctl(sd, SIOCGIFADDR, &ifr) < 0) { printf("ioctl error: %s\n", strerror(errno)); close(sd); return -1; } memcpy(&sin, &ifr.ifr_addr, sizeof(sin)); snprintf(ip, IP_SIZE, "%s", inet_ntoa(sin.sin_addr)); close(sd); return 0;}