Linux C 網路編程，linux網路編程

Linux C 網路編程，linux網路編程

擷取本地 ip 地址，mac，通過網域名稱擷取對應的 ip，

是網路編程可能遇到的比較常見的操作了，所以總結如下（封裝了3個函數），

直接上代碼：

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <errno.h>#include <unistd.h>#include <netdb.h>#include <net/if.h>#include <arpa/inet.h>#include <sys/ioctl.h>#include <sys/types.h>#include <sys/socket.h>#define MAC_SIZE18#define IP_SIZE16// function declareint get_ip_by_domain(const char *domain, char *ip); // 根據網域名稱擷取ipint get_local_mac(const char *eth_inf, char *mac); // 擷取本機macint get_local_ip(const char *eth_inf, char *ip); // 擷取本機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;}// 根據網域名稱擷取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; // 只擷取第一個 ip}}return -1;}// 擷取本機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);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;}// 擷取本機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 deviceif (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;}

測試回合結果如下：