Question

TCP 客户端编程问题

我要写个TCP client程序，要求给服务端发送数据之后接收服务端返回数据，应该怎么写

Answer 1

client.cpp

#include <stdio.h>
#include <winsock2.h>
#pragma comment(lib, "ws2_32.lib")
void main() {

// 初始化 Winsock.
WSADATA wsaData;
int iResult = WSAStartup( MAKEWORD(2,2), &wsaData );
if ( iResult != NO_ERROR )
printf("Error at WSAStartup()\n");

// 建立socket socket.
SOCKET client;
client = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );

if ( client == INVALID_SOCKET ) {
printf( "Error at socket(): %ld\n", WSAGetLastError() );
WSACleanup();
return;
}

// 连接到服务器.
sockaddr_in clientService;

clientService.sin_family = AF_INET;
clientService.sin_addr.s_addr = inet_addr( "127.0.0.1" );
clientService.sin_port = htons( 27015 );

if ( connect( client, (SOCKADDR*) &clientService, sizeof(clientService) ) == SOCKET_ERROR) {
printf( "Failed to connect.\n" );
WSACleanup();
return;
}

// 发送并接收数据.
int bytesSent;
int bytesRecv = SOCKET_ERROR;
char sendbuf[32] = "Client: Sending data.";
char recvbuf[32] = "";

bytesSent = send( client, sendbuf, strlen(sendbuf), 0 );
printf( "Bytes Sent: %ld\n", bytesSent );

while( bytesRecv == SOCKET_ERROR ) {
bytesRecv = recv( client, recvbuf, 32, 0 );
if ( bytesRecv == 0 || bytesRecv == WSAECONNRESET ) {
printf( "Connection Closed.\n");
break;
}
if (bytesRecv < 0)
return;
printf( "Bytes Recv: %ld\n", bytesRecv );
}

return;
}