server
#include <stdio.h>
#include <winsock2.h>
#include <iostream> #pragma comment(lib, "WS2_32.lib") #define PORT 9999
#define DATA_BUFSIZE 8192 typedef struct _SOCKET_INFORMATION{
CHAR Buffer[DATA_BUFSIZE]; //发送和接收数据的缓冲区
WSABUF DataBuf; //定义发送和接收数据缓冲区的结构体，包括缓冲区长度和内容
SOCKET Socket; //与客户端进行通信的套接字
DWORD BytesSEND; //保存套接字发送的字节数
DWORD BytesRECV; //保存套接字接收的字节数
} SOCKET_INFOMATION, * LPSOCKET_INFORMATION; DWORD TotalSockets = ;
LPSOCKET_INFORMATION SocketArray[FD_SETSIZE]; bool CreateSocketInformation(SOCKET s)
{
LPSOCKET_INFORMATION SI; //用于保存套接字的信息
//为SI分配内存空间
if ((SI = (LPSOCKET_INFORMATION)GlobalAlloc(GPTR, sizeof SOCKET_INFOMATION)) == NULL)
{
printf("GlobalAlloc() failed with error %d\n", GetLastError());
return FALSE;
} //初始化SI的值
SI->Socket = s;
SI->BytesSEND = ;
SI->BytesRECV = ; SocketArray[TotalSockets] = SI;
TotalSockets++; return true;
} void FreeSocketInformation(DWORD Index)
{
LPSOCKET_INFORMATION SI = SocketArray[Index];
DWORD i; closesocket(SI->Socket);
GlobalFree(SI);
if (Index != (TotalSockets - ))
{
for (i = Index; i < TotalSockets; i++)
{
SocketArray[i] = SocketArray[i + ];
}
} TotalSockets--;
} int main()
{
SOCKET ListenSocket; //监听套接字
SOCKET AcceptSocket; //与客户端通信的套接字
SOCKADDR_IN InternetAddr; //服务器地址
WSADATA wsaData;
int Ret; FD_SET WriteSet; //获取可写套接字集合
FD_SET ReadSet; //获取可读性套接字集合
DWORD Total = ; //处于就绪状态的套接字
DWORD SendBytes; //发送套接字
DWORD RecvBytes; //接收的套接字 //初始化WinSock环境
if ((Ret = WSAStartup(MAKEWORD(, ), &wsaData) != ))
{
printf("WSAStartup() failed with error %d\n", Ret);
WSACleanup();
return -;
} //创建用于监听的套接字
if ((ListenSocket = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, , WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)
{
printf("WSASocket() failed with error %d\n", WSAGetLastError());
return -;
} //设置监听地址和端口
InternetAddr.sin_family = AF_INET;
InternetAddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
InternetAddr.sin_port = htons(PORT); //绑定监听套接字到本地地址和端口
if (bind(ListenSocket, (PSOCKADDR)&InternetAddr, sizeof InternetAddr) == INVALID_SOCKET)
{
printf("bind() failed with error %d\n", WSAGetLastError());
return -;
} //开始监听
if (listen(ListenSocket, ))
{
printf("listen() failed with error %d\n", WSAGetLastError());
return -;
} //设置成非阻塞方式
ULONG NonBlock = ;
if (ioctlsocket(ListenSocket, FIONBIO, &NonBlock))
{
printf("ioctlsocket() failed with error %d\n", WSAGetLastError());
return -;
} CreateSocketInformation(ListenSocket);//ListenSocket套接字创建对应的SOCKET_INFORMATION,把ListenSocket添加到SocketArray数组中 while (true)
{
FD_ZERO(&ReadSet);//读套接字清零
FD_ZERO(&WriteSet);//写套接字清零 FD_SET(ListenSocket, &ReadSet);//向ReadSet中添加监听套接字ListenSocket for (DWORD i = ; i < TotalSockets; ++i)
{
LPSOCKET_INFORMATION SocketInfo = SocketArray[i];
FD_SET(SocketInfo->Socket, &ReadSet);
FD_SET(SocketInfo->Socket, &WriteSet);
} if((Total = select(, &ReadSet, &WriteSet, NULL, NULL)) == SOCKET_ERROR){//刚开始为什么监听套接字没有可写返回，而与客户端连接的套接字总是可写？？？
printf("select() returned with error %d\n", WSAGetLastError());
return -;
} for (DWORD i = ; i < TotalSockets; i++)
{
LPSOCKET_INFORMATION SocketInfo = SocketArray[i];//SocketArray保存了所有监听的可读和可写的套接字
if (FD_ISSET(SocketInfo->Socket, &ReadSet))//判断套接字是否可读
{
if (SocketInfo->Socket == ListenSocket)//对于监听套接字表示有新的客户端连接
{
Total--;
if ((AcceptSocket = accept(ListenSocket, NULL, NULL)) != INVALID_SOCKET)
{
NonBlock = ;
if (ioctlsocket(AcceptSocket, FIONBIO, &NonBlock) == SOCKET_ERROR)//设置AcceptSocket套接字为非阻塞套接字，这样与客户端通信就不会阻塞了
{
printf("ioctlsocket() failed with error %d\n", WSAGetLastError());
return -;
} if (CreateSocketInformation(AcceptSocket) == false)//将AcceptSocket添加到SocketArray数组中
{
return -;
}
}
else
{
if (WSAGetLastError() != WSAEWOULDBLOCK)
{
printf("accept() failed with error %d\n", WSAGetLastError());
return -;
}
}
}
else//接收数据
{
Total--;
memset(SocketInfo->Buffer, , sizeof SocketInfo->Buffer);
SocketInfo->DataBuf.buf = SocketInfo->Buffer;
SocketInfo->DataBuf.len = DATA_BUFSIZE; DWORD Flags = ;
if (WSARecv(SocketInfo->Socket, &(SocketInfo->DataBuf), , &RecvBytes, &Flags, NULL, NULL) == SOCKET_ERROR)
{
if (WSAGetLastError() != WSAEWOULDBLOCK)
{
printf("WSARecv() failed with error %d\n", WSAGetLastError());
FreeSocketInformation(i);
}
continue;
}
else
{
SocketInfo->BytesRECV = RecvBytes;
SocketInfo->DataBuf.buf[RecvBytes] = '\0';
if (RecvBytes == )
{
FreeSocketInformation(i);
continue;
}
else
{
std::cout << SocketInfo->DataBuf.buf << std::endl;// 如果成功接收数据，则打印收到的数据
}
}
}
}
else
{
if (FD_ISSET(SocketInfo->Socket, &WriteSet))//可写会一直被调用，判断大于其写缓冲的最低水位
{
Total--;
SocketInfo->DataBuf.buf = SocketInfo->Buffer + SocketInfo->BytesSEND;// 初始化缓冲区位置
SocketInfo->DataBuf.len = SocketInfo->BytesRECV - SocketInfo->BytesSEND;// 初始化缓冲区长度 if (SocketInfo->DataBuf.len > )// 如果有需要发送的数据，则发送数据
{
if (WSASend(SocketInfo->Socket, &(SocketInfo->DataBuf), , &SendBytes, , NULL, NULL) == SOCKET_ERROR)
{
if (WSAEWOULDBLOCK != WSAGetLastError())
{
printf("WSASend() failed with error %d\n", WSAGetLastError());
FreeSocketInformation(i);
}
continue;
}
else
{
SocketInfo->BytesSEND += SendBytes; //记录发送数据的字节数目
if (SocketInfo->BytesSEND == SocketInfo->BytesRECV)
{
SocketInfo->BytesSEND = ;
SocketInfo->BytesRECV = ;
}
}
}
}
}
}
}
system("pause");
return ; }
client
#include <winsock.h>
#include <iostream>
#define BUFSIZE 64
#define PORT 9999 #pragma comment(lib, "WS2_32.lib")
int main()
{
WSADATA wsaData;
SOCKET sClient; sockaddr_in addrServ;
char buf[BUFSIZE];
int retVal; if(WSAStartup(MAKEWORD(,), &wsaData) != )
{
std::cout << "WSAStartup失败!" << std::endl;
return -;
} sClient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (INVALID_SOCKET == sClient)
{
std::cout << "socket() 错误!" << std::endl;
WSACleanup();
return -;
} addrServ.sin_family = AF_INET;
addrServ.sin_port = htons(PORT);
addrServ.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); retVal = connect(sClient, (LPSOCKADDR)&addrServ, sizeof(addrServ));
if (SOCKET_ERROR == retVal)
{
std::cout << "connect 错误!" << std::endl;
closesocket(sClient);
WSACleanup();
return -;
} while(true)
{
std::cout << "输入要发给服务器的内容:" << std::endl;
char msg[BUFSIZE];
std::cin.getline(msg, BUFSIZE);
ZeroMemory(buf, BUFSIZE);
strcpy(buf, msg);
retVal = send(sClient, buf, strlen(buf), );
if (SOCKET_ERROR == retVal)
{
std::cout << "发送失败" << std::endl;
closesocket(sClient);
WSACleanup();
return -;
} retVal = recv(sClient, buf, sizeof buf, );
std::cout << "从服务器端接收：" << buf << std::endl;
if (strcmp(buf, "quit") == )
{
std::cout << "quit" << std::endl;
break;
}
}
closesocket(sClient);
WSACleanup();
return ;
}