獲得本地IP的三種方法
阿新 • • 發佈:2019-02-09
- 方法1,windows平臺能拿到所有網絡卡IP,linux只能獲得 "127.0.0.1"
int m_get_localIP(char** ipList, int num) { int i = 0; const char* ip = NULL; struct hostent* h = NULL; char hostname[128] = {0}; if(gethostname(hostname, sizeof(hostname)) != 0 || (h = gethostbyname(hostname)) == NULL) { return -1; } //get the ip address if it has multiple for(i = 0;i < num && h->h_addr_list[i];i++) { ip = inet_ntoa(*(struct in_addr*)h->h_addr_list[i]); if(strcmp(ip, "127.0.0.1") != 0) { strcpy(ipList[i++], ip); } } return i; }
- 方法2,linux平臺可以拿到所有網絡卡IP,windows沒有定義SIOCGIFCONF 和SIOCGIFADDR
int m_get_localIP(char** ipList, int num) { int fd = -1; int i = -1, ret = 0; const char* ip = NULL; struct ifconf ifc = {0}; ///if.h struct ifreq* buf = NULL; if((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { return -1; } ifc.ifc_len = num * sizeof(struct ifreq); buf = (struct ifreq*)malloc(ifc.ifc_len); ifc.ifc_buf = (caddr_t)buf; if(ioctl(fd, SIOCGIFCONF, (char*)&ifc) == 0) //ioctl.h { i = 0; ret = ifc.ifc_len / sizeof(struct ifreq); while(ret-- > 0 && i < num) { if((ioctl(fd, SIOCGIFADDR, (char*)&buf[ret])) == 0) { ip = (inet_ntoa(((struct sockaddr_in*)(&buf[ret].ifr_addr))->sin_addr));//types if(strcmp(ip, "127.0.0.1") != 0) { strcpy(ipList[i++], ip); } } } } close(fd); free(buf); return i; }
- 方法三,各平臺通用,但是隻能獲得系統分配的網絡卡IP,不能拿到所有網絡卡IP
int m_get_localIP(char** ipList, int num) { int fd = -1; int i = -1, ret = 0; const char* ip = NULL; struct sockaddr_in addr = {0}; if((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { return -1; } memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_addr.s_addr = inet_addr("8.8.8.8"); addr.sin_port = htons(80); ret = sizeof(addr); ret = connect(fd, (struct sockaddr*)&addr, ret); i = 0; ret = sizeof(addr); if(getsockname(fd, (struct sockaddr*)&addr, (int*)&ret) == 0) { fprintf(stdout, "ip=%s\n", inet_ntoa(addr.sin_addr)); } close(fd); return i; }