实现服务器端多次写，客户端多次读。

#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
#pragma comment(lib,"WS2_32.lib")

void ErrorHandling(char* message);

int main(int argc, char* argv[])
{
WSADATA	wsaData;
SOCKET hServSock, hClntSock;
SOCKADDR_IN servAddr, clntAddr;

int szClntAddr;
char message[]="Hello World!";
int i;
if(argc!=2)
{
printf("Usage : %s <port>\n", argv[0]);
exit(1);
}

if(WSAStartup(MAKEWORD(2, 2), &wsaData)!=0)
ErrorHandling("WSAStartup() error!");

hServSock=socket(PF_INET, SOCK_STREAM, 0);
if(hServSock==INVALID_SOCKET)
ErrorHandling("socket() error");

memset(&servAddr, 0, sizeof(servAddr));
servAddr.sin_family=AF_INET;
servAddr.sin_addr.s_addr=htonl(INADDR_ANY);
servAddr.sin_port=htons(atoi(argv[1]));

if(bind(hServSock, (SOCKADDR*) &servAddr, sizeof(servAddr))==SOCKET_ERROR)
ErrorHandling("bind() error");

if(listen(hServSock, 5)==SOCKET_ERROR)
ErrorHandling("listen() error");

szClntAddr=sizeof(clntAddr);
hClntSock=accept(hServSock, (SOCKADDR*)&clntAddr,&szClntAddr);
if(hClntSock==INVALID_SOCKET)
ErrorHandling("accept() error");

for(i=0;i<sizeof(message);i++)

{
send(hClntSock, &message[i], 1, 0);
}
closesocket(hClntSock);
closesocket(hServSock);
WSACleanup();
return 0;
}

void ErrorHandling(char* message)
{
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}

#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
#pragma comment(lib,"WS2_32.lib")

void ErrorHandling(char* message);

int main(int argc, char* argv[])
{
WSADATA wsaData;
SOCKET hSocket;
SOCKADDR_IN servAddr;

char message[30];
int strLen=0;
int idx=0, readLen=0;

if(argc!=3)
{
printf("Usage : %s <IP> <port>\n", argv[0]);
exit(1);
}

if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
ErrorHandling("WSAStartup() error!");

hSocket=socket(PF_INET, SOCK_STREAM, 0);
if(hSocket==INVALID_SOCKET)
ErrorHandling("hSocket() error");

memset(&servAddr, 0, sizeof(servAddr));
servAddr.sin_family=AF_INET;
servAddr.sin_addr.s_addr=inet_addr(argv[1]);
servAddr.sin_port=htons(atoi(argv[2]));

if(connect(hSocket, (SOCKADDR*)&servAddr, sizeof(servAddr))==SOCKET_ERROR)
ErrorHandling("connect() error!");

while(readLen=recv(hSocket, &message[idx++], 1, 0))
{
if(readLen==-1)
ErrorHandling("read() error!");

strLen+=readLen;
}

printf("Message from server: %s \n", message);
printf("Function read call count: %d \n", strLen);

closesocket(hSocket);
WSACleanup();
return 0;
}

void ErrorHandling(char* message)
{
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}