标签：命令 服务端 invalid 防止 main start put secure break
对fd_set的理解，可以参考下：
https://www.cnblogs.com/wuyepeng/p/9745573.html
int select(int nfds, fd_set* readset, fd_set* writeset, fe_set* exceptset, struct timeval* timeout);
参数：
nfds 需要检查的文件描述字个数(集合中最大描述符+1)
readset 用来检查可读性的一组文件描述字。
writeset 用来检查可写性的一组文件描述字。
exceptset 用来检查是否有异常条件出现的文件描述字。(注：错误不包括在异常条件之内)
timeout 超时，填NULL为阻塞，填0为非阻塞，其他为一段超时时间
返回值：
返回fd的总数，错误时返回SOCKET_ERROR
select对集合进行筛选，返回时，只保留符合状态的描述符
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fd_set fdset;
FD_ZERO(&fdset);
FD_SET(1, &fdset); //将套接字1加入 fdset集合
FD_SET(2, &fdset); //将套接字2加入 fdset集合
FD_SET(3, &fdset); //将套接字3加入 fdset集合
FD_SET(7, &fdset); //将套接字7加入 fdset集合
FD_CLR(3, &fdset); //将套接字3从 fdset 集合移除，fdset.fdReadd_array[2]就被清除了，
数组后面的数据依次往前提，即7被放到了fd_array[2]
服务端：
//vc的第一套socket，第二套socket，可能存在冲突 #define WIN32_LEAN_AND_MEAN #define _WINSOCK_DEPRECATED_NO_WARNINGS //也可以放到工程属性，预处理中 #include <windows.h> #include <WinSock2.h> #include <stdio.h> #include <vector> #pragma comment(lib, "ws2_32.lib") enum CMD { CMD_LOGIN, CMD_LOGIN_RET, CMD_LOGOUT, CMD_LOGOUT_RET, CMD_ERROR }; struct DataHeader { int dataLength; CMD cmd; }; struct Login :public DataHeader { Login() { dataLength = sizeof(Login); cmd = CMD_LOGIN; } char userName[32]; char passWord[32]; }; struct LoginResult :public DataHeader { LoginResult() { dataLength = sizeof(LoginResult); cmd = CMD_LOGIN_RET; ret = 0; } int ret; }; struct LogOut :public DataHeader { LogOut() { dataLength = sizeof(LogOut); cmd = CMD_LOGOUT; } char userName[32]; }; struct LogOutResult :public DataHeader { LogOutResult() { dataLength = sizeof(LogOutResult); cmd = CMD_LOGOUT_RET; ret = 0; } int ret; }; int processor(SOCKET _cSock) { //5 接收客户端数据 char szRecv[1024] = {}; int nLen = recv(_cSock, szRecv, sizeof(DataHeader), 0); if (nLen <= 0) { printf("客户端%d已退出。\n", _cSock); return -1; } DataHeader* pHeader = (DataHeader*)szRecv; switch (pHeader->cmd) { case CMD_LOGIN: { recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0); Login *pLogin = (Login*)szRecv; printf("客户端%d,cmd logint,user:%s,password:%s\n", _cSock, pLogin->userName, pLogin->passWord); //---------------------------- //---------------------------- LoginResult longinRet = {}; send(_cSock, (const char*)&longinRet, sizeof(LoginResult), 0); } break; case CMD_LOGOUT: { recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0); LogOut *pLogOut = (LogOut*)szRecv; printf("客户端%d,cmd logout,user:%s\n", _cSock, pLogOut->userName); //---------------------------- LogOutResult logOutRet = {}; send(_cSock, (const char*)&logOutRet, sizeof(LogOutResult), 0); } break; default: { //剩余的垃圾数据是否要读取出来？ if (pHeader->dataLength >0) { recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0); } DataHeader header = {}; header.cmd = CMD_ERROR; header.dataLength = 0; send(_cSock, (const char*)&header, sizeof(DataHeader), 0); } break; } return 0; } std::vector<SOCKET> g_clients; int main() { //启动Windows socket 2.x环境 WORD ver = MAKEWORD(2, 2); WSADATA dat; WSAStartup(ver, &dat); //--用Socket API建立简易TCP服务端 //1.建立一个socket SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); //2 bind绑定用于接受客户端连接的网络端口 sockaddr_in _sin = {}; _sin.sin_family = AF_INET; _sin.sin_port = htons(4567);//host to net unsigned _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); //使用127.0.0.1可以防止外网访问 //启用本机全部的ip地址可以使用，INADDR_ANY if (SOCKET_ERROR == bind(_sock, (sockaddr*)&_sin, sizeof(sockaddr_in))) { printf("错误，绑定网络端口失败...\n"); } else { printf("绑定网络端口成功...\n"); } //3 listen 监听网络端口 if (SOCKET_ERROR == listen(_sock, 5)) { printf("错误，监听网络端口失败...\n"); } else { printf("监听网络端口成功...\n"); } while (true) { fd_set fdRead; fd_set fdWrite; fd_set fdExp; FD_ZERO(&fdRead); FD_ZERO(&fdWrite); FD_ZERO(&fdExp); FD_SET(_sock, &fdRead); FD_SET(_sock, &fdWrite); FD_SET(_sock, &fdExp);
//接入的客户端socket放入到 可读集合中，通过select来筛选出具有可读状态的socket for (size_t n = 0; n<g_clients.size(); n++) { FD_SET(g_clients[n], &fdRead); } int ret = select(_sock+1, &fdRead, &fdWrite, &fdExp, nullptr); if (ret < 0) { printf("select任务结束。\n"); break; } if ( FD_ISSET(_sock, &fdRead) ) { FD_CLR(_sock, &fdRead);//从集合移除了_sock sockaddr_in clientAddr = {}; int nAddrLen = sizeof(clientAddr); SOCKET _cSock = INVALID_SOCKET; _cSock = accept(_sock, (sockaddr*)&clientAddr, &nAddrLen); if (INVALID_SOCKET == _cSock) { printf("错误，接受到无效客户端socket...\n"); } g_clients.push_back(_cSock); printf("新客户端加入:socket=%d,IP=%s\n", _cSock, inet_ntoa(clientAddr.sin_addr)); } for (size_t n=0;n<fdRead.fd_count;n++) { if (-1 == processor(fdRead.fd_array[n])) { auto iter = find(g_clients.begin(), g_clients.end(), fdRead.fd_array[n]); if (iter != g_clients.end()) { closesocket(*iter); g_clients.erase(iter); } } } } //6 关闭套接字closesocket for (size_t n = 0; n<g_clients.size(); n++) { closesocket(g_clients[n]); } closesocket(_sock); //清除Windows socket环境 WSACleanup(); printf("已退出。\n"); getchar(); return 0; }
客户端：
#define WIN32_LEAN_AND_MEAN #define _WINSOCK_DEPRECATED_NO_WARNINGS //也可以放到工程属性，预处理中 //#define _CRT_SECURE_NO_WARNINGS #include <windows.h> #include <WinSock2.h> #include <stdio.h> #pragma comment(lib, "ws2_32.lib") enum CMD { CMD_LOGIN, CMD_LOGIN_RET, CMD_LOGOUT, CMD_LOGOUT_RET, CMD_ERROR }; struct DataHeader { int dataLength; CMD cmd; }; struct Login:public DataHeader { Login() { dataLength = sizeof(Login); cmd = CMD_LOGIN; } char userName[32]; char passWord[32]; }; struct LoginResult :public DataHeader { LoginResult() { dataLength = sizeof(LoginResult); cmd = CMD_LOGIN_RET; ret = 1; } int ret; }; struct LogOut :public DataHeader { LogOut() { dataLength = sizeof(LogOut); cmd = CMD_LOGOUT; } char userName[32]; }; struct LogOutResult :public DataHeader { LogOutResult() { dataLength = sizeof(LogOutResult); cmd = CMD_LOGOUT_RET; ret = 1; } int ret; }; int main() { //启动Windows socket 2.x环境 WORD ver = MAKEWORD(2, 2); WSADATA dat; WSAStartup(ver, &dat); //--------------------------- //--用Socket API建立简易TCP客户端 //1 建立一个socket SOCKET _sock = INVALID_SOCKET; _sock = socket(AF_INET, SOCK_STREAM, 0); if (INVALID_SOCKET == _sock) { printf("错误，建立Socket失败...\n"); } else { printf("建立Socket成功...\n"); } //2 连接服务器connect sockaddr_in _sin = {}; _sin.sin_family = AF_INET; _sin.sin_port = htons(4567);//host to net unsigned _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); int ret = connect(_sock, (sockaddr*)&_sin, sizeof(sockaddr_in)); if (SOCKET_ERROR == ret) { printf("错误，连接服务端失败...\n"); closesocket(_sock); //清除Windows socket环境 WSACleanup(); printf("已退出。"); getchar(); return 0; } else { printf("连接服务端成功...\n"); } while (true) { //3输入请求命令 char cmdBuf[128] = {}; scanf_s("%s", cmdBuf, 128); getchar(); //4处理请求 if (0 == strcmp(cmdBuf, "exit")) { printf("收到exit命令，任务结束。\n"); break; } else if(0 == strcmp(cmdBuf, "login")) { Login login = {}; strcpy_s(login.userName, "jj"); strcpy_s(login.passWord, "ww"); int nSend = send(_sock, (const char*)&login, sizeof(Login), 0); printf("send length %d\n", nSend); LoginResult cmd_ret = {}; recv(_sock, (char*)&cmd_ret, sizeof(LoginResult), 0); printf("Login result:%d\n", cmd_ret.ret); } else if (0 == strcmp(cmdBuf, "logout")) { LogOut log_out = {}; strcpy_s(log_out.userName, "jj"); send(_sock, (const char*)&log_out, sizeof(LogOut), 0); LogOutResult cmd_ret = {}; recv(_sock, (char*)&cmd_ret, sizeof(LogOutResult), 0); printf("LogOut result:%d\n", cmd_ret.ret); } else { printf("wrong cmd, please input cmd again.\n"); } } //7 关闭套接字closesocket closesocket(_sock); //清除Windows socket环境 WSACleanup(); printf("已退出"); getchar(); return 0; }
标签：命令 服务端 invalid 防止 main start put secure break
原文地址：https://www.cnblogs.com/zhangxuan/p/14284337.html
