一个基于SOCKET套接字的小程序，适合初级程序员参考使用

// Server.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include <iostream.h> #include <WINSOCK2.H> #pragma comment(lib, "wsock32.lib") #define SERVER_EXIT_OK 0 //服务器正常退出 #define SERVER_DLL_REEOR 1 //调用Windows sockets DLL失败 #define SERVER_API_ERROR 2 //调用Windows sockets API失败 #define SERVERPORT 5555//服务器TCP端口 #define MAX_NUM_BUF 64 //缓冲区最大尺寸 //变量 char bufRecv[MAX_NUM_BUF]; //读缓冲区 char bufSend[MAX_NUM_BUF]; //写缓冲区 SOCKET sServer; //服务器监听套接字 SOCKET sClient; //接受客户端套接字 BOOL bConning; //与客户端的连接状态 //函数 void InitMember(void); //初始化成员变量 int ExitClient(int nExit); //客户端退出 BOOL RecvLine(SOCKET s, char* buf); //读取一行数据 BOOL SendLine(SOCKET s, char* buf); //发送一行数据 int HandleSocketError(char *str); //对Windows sockets API调用错误处理 void ShowSocketMsg(char* str); //显示错误信息 //主函数 int main(int argc, char* argv[]) { InitMember(); //初始化变量 WORD wVersionRequested; //应用程序需要Windows sockets DLL的版本 WSADATA wsaData; //Windows sockets DLL版本信息 int retVal; //调用Windows sockets API返回值 //初始化Windows Sockets DLL wVersionRequested = MAKEWORD(1,1); retVal = WSAStartup(wVersionRequested, &wsaData); if ( 0 != retVal ) { ShowSocketMsg("Can not find a usable Windows Sockets dll!"); return SERVER_DLL_REEOR; } //确保WinSock DLL支持1.1 if ( LOBYTE( wsaData.wVersion ) != 1 || HIBYTE( wsaData.wVersion ) != 1) { ShowSocketMsg("Can not find a usable Windows Sockets dll!"); WSACleanup( ); return SERVER_DLL_REEOR; } //创建套接字 sServer= socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if(INVALID_SOCKET == sServer) { return HandleSocketError("Failed socket()!"); } //服务器套接字地址 SOCKADDR_IN addrServ; addrServ.sin_family = AF_INET; addrServ.sin_port = htons(SERVERPORT); addrServ.sin_addr.s_addr = INADDR_ANY; //绑定套接字 retVal = bind(sServer, (LPSOCKADDR)&addrServ, sizeof(SOCKADDR_IN)); if(SOCKET_ERROR == retVal) { closesocket(sServer); //关闭套接字 return HandleSocketError("Failed bind()!"); //错误处理 } //开始监听 retVal = listen(sServer, 1); if(SOCKET_ERROR == retVal) { closesocket(sServer); //关闭套接字 return HandleSocketError("Failed listen()!");//错误处理 } //等待客户端的连接 cout << "Server succeeded!" << endl; cout << "Waiting for new clients..." << endl; //接受客户端请求 sockaddr_in addrClient; int addrClientlen = sizeof(addrClient); sClient = accept(sServer,(sockaddr FAR*)&addrClient, &addrClientlen); if(INVALID_SOCKET == sClient) { closesocket(sServer); //关闭套接字 return HandleSocketError("Failed accept()!"); //错误处理 }else{ bConning = TRUE; //客户端请求成功 } //显示客户端的IP和端口 char *pClientIP = inet_ntoa(addrClient.sin_addr); u_short clientPort = ntohs(addrClient.sin_port); cout<<"Accept a client."<<endl; cout<<"IP: "<<pClientIP<<endl; cout<<"Port: "<<clientPort<<endl; //接收客户端数据 if (!RecvLine(sClient, bufRecv)) { return ExitClient(SERVER_API_ERROR);//退出 } //显示客户端数据 cout << bufRecv<<endl; //向客户端发送数据 strcpy(bufSend, "Hello,Client!\n"); if (!SendLine(sClient, bufSend)) { return ExitClient(SERVER_API_ERROR); } //显示退出信息 cout << "Server exiting..." << endl; //退出 return ExitClient(SERVER_EXIT_OK); } /* * 初始化成员变量 */ void InitMember(void) { //初始化读和写缓冲区 memset(bufRecv, 0, MAX_NUM_BUF); memset(bufSend, 0, MAX_NUM_BUF); //初始化 sServer = INVALID_SOCKET; sClient = INVALID_SOCKET; //没有连接状态 bConning = FALSE; } /* * 退出 */ int ExitClient(int nExit) { closesocket(sServer); //关闭监听套接字 closesocket(sClient); //关闭连接客户端套接接 WSACleanup(); //卸载Windows sockets DLL 清理内存 return nExit; //退出 } /* * 读一行数据 */ BOOL RecvLine(SOCKET s, char* buf) { BOOL retVal = TRUE; //返回值 BOOL bLineEnd = FALSE; //行结束 int nReadLen = 0; //读入字节数 int nDataLen = 0; //数据长度 while (!bLineEnd && bConning) //与客户端连接 没有换行 { nReadLen = recv(s, buf + nDataLen, 1, 0);//每次接收一个字节 //错误处理 if (SOCKET_ERROR == nReadLen) { int nErrCode = WSAGetLastError();//错误代码 if (WSAENOTCONN == nErrCode) { ShowSocketMsg("The socket is not connected!"); }else if(WSAESHUTDOWN == nErrCode) { ShowSocketMsg("The socket has been shut down!"); }else if (WSAETIMEDOUT == nErrCode) { ShowSocketMsg("The connection has been dropped!"); }else if (WSAECONNRESET == nErrCode) { ShowSocketMsg("The virtual circuit was reset by the remote side!"); }else{} retVal = FALSE; //读数据失败 break; //跳出循环 } if (0 == nReadLen)//客户端关闭 { retVal = FALSE; //读数据失败 break ; //跳出循环 } //读入数据 if ('\n' == *(buf + nDataLen)) //换行符 { bLineEnd = TRUE; //接收数据结束 }else{ nDataLen += nReadLen; //增加数据长度 } } return retVal; } /* * //发送一行数据 */ BOOL SendLine(SOCKET s, char* str) { int retVal;//返回值 retVal = send(s, str, strlen(str), 0);//一次发送 //错误处理 if (SOCKET_ERROR == retVal) { int nErrCode = WSAGetLastError();//错误代码 if (WSAENOTCONN == nErrCode) { ShowSocketMsg("The socket is not connected!"); }else if(WSAESHUTDOWN == nErrCode) { ShowSocketMsg("The socket has been shut down!"); }else if (WSAETIMEDOUT == nErrCode) { ShowSocketMsg("The connection has been dropped!"); }else{} return FALSE; //发送失败 } return TRUE; //发送成功 } /* * 错误处理 */ int HandleSocketError(char *str) { ShowSocketMsg(str); //显示错误消息 WSACleanup(); //卸载Windows socket DLL return SERVER_API_ERROR;//退出应用程序 } /* * 显示错误 */ void ShowSocketMsg(char* str) { MessageBox(NULL, str, "SERVER ERROR", MB_OK); } // unsigned long ulAddr = inet_addr("192.168.1.100"); // char* pAddr = inet_ntoa(*(in_addr*)(&ulAddr)); // int retVal = listen(sServer, 2); //监听 // if(SOCKET_ERROR == retVal) // { // closesocket(sServer); //关闭套接字 // int nErrCode = WSAGetLastError(); // if (WSAENETDOWN == nErrCode) //错误处理 // { // //处理 // } // }