socket --------tcp/ip-优快云博客

本文通过C/S模式的网络通信实例，详细解析了客户端和服务端如何通过Winsock库进行通信，包括套接字的创建、监听、接受、收发消息等关键步骤。

//server.c

#include <Winsock.h>
#include <windows.h>
#include <stdio.h>
#include <string.h>
#pragma comment(lib,"wsock32.lib")

#define PORT 12345
#define BUFFER 1024

int main(int argc, char* argv[])
{

WSADATA       wsaData;
SOCKET        server;
// char          buf_send[BUFFER];
char  buf_recv[BUFFER]="hello!";
int len;
struct sockaddr_in serv,client;   //声明两个地址结构体变量

// memset(buf_recv,0,sizeof(buf_recv));
// memset(buf_send,0,sizeof(buf_send));

//加载套接字库
if(WSAStartup(MAKEWORD(2,2),&wsaData) != 0)
{
  printf("Winsock load failed\n");
  exit(0);
}

server = socket(AF_INET,SOCK_STREAM,0);

if(server == INVALID_SOCKET)
{
printf("socket failed:%d\n",WSAGetLastError());
exit(0);
}

//创建一个套接字 AD_INET(IPV4协议) SOCK_STREAM（TCP协议）
serv.sin_family = AF_INET;          //协议族必须和创建套接字时候一样（socket）
serv.sin_port = htons(PORT);        //端口 htons转换为网络字节序
serv.sin_addr.s_addr = htonl(INADDR_ANY);  //绑定的地址 htonl转换为网络字节序
             //INADDR_ANY 默认的网卡地址为本机
//bind 绑定地址
if(bind(server,(SOCKADDR *)&serv,sizeof(serv))==SOCKET_ERROR)
{
  printf("bind()failed:%d\n",WSAGetLastError());
  exit(0);
}
//监听客户端
if(listen(server,5)==SOCKET_ERROR)
{
  printf("listen()failed:%d\n",WSAGetLastError());
  exit(0);
}

len=sizeof(client);
//accept阻塞直到有新的连接
  if(accept(server,(struct sockaddr*)&client,&len) == INVALID_SOCKET)
  {
   printf("accept()failed:%d\n",WSAGetLastError());
   exit(0) ;
  }

printf("accepted client IP:[%s]\n,port:[%d]\n",inet_ntoa(client.sin_addr),ntohs(client.sin_port));

while(1)
{
   //recv读取消息
   if(recv(server,buf_recv,sizeof(buf_recv),0) == 0)
   {
    printf("recv()failed:%d\n",WSAGetLastError());
    exit(0);
   }
   printf("recv()data from client:%s\n",buf_recv);

   //send发送请求
   printf("pleasse send message:\n");
   gets(buf_recv);
   if(send(server,buf_recv,sizeof(buf_recv),0) == 0)
   {
    printf("send()failed:%d\n",WSAGetLastError());
    exit(0);
   }

closesocket(server); //关闭套接字
WSACleanup(); //关闭套接字库
}
}

//client.c

#include <Winsock.h>
#include <windows.h>
#include <stdio.h>
#include <string.h>
#pragma comment(lib,"wsock32.lib")

#define PORT 12345
#define BUFFER 1024

void main(int argc,char *argv[])
{
WSADATA    wsaData;
SOCKET    client;
char    buf_recv[BUFFER];
// char buf_send[BUFFER];
struct sockaddr_in   serv;
// struct sockaddr_in   client;

memset(buf_recv,0,sizeof(buf_recv));
// memset(buf_send,0,sizeof(buf_send));
if(WSAStartup(MAKEWORD(2,2),&wsaData)!=0)
{
  printf("Winsock load failed\n");
  exit(0);
}

//为地址结构体赋值
serv.sin_family=AF_INET;   //地址族
serv.sin_port=htons(PORT);   //服务端监听的端口
serv.sin_addr.s_addr=inet_addr("192.168.2.100"); //服务端的IP地址

client=socket(AF_INET,SOCK_STREAM,0); //创建套接字
if(client==INVALID_SOCKET)
{
printf("socket failed:%d\n",WSAGetLastError());
exit(0);
}

//连接服务器
if(connect(client,(struct sockaddr*)&serv,sizeof(serv)) == INVALID_SOCKET)
{
printf("connet()failed:%d\n",WSAGetLastError());
exit(0);
}
printf("connect server sucessful!\n");

while(1)
{

  //send发送请求
   printf("pleasse send message!\n");
   gets(buf_recv);
   if(send(client,buf_recv,sizeof(buf_recv),0) == 0)
   {
    printf("send failed:%d\n",WSAGetLastError());
    exit(0);
   }
  //recv读取消息
   if(recv(client,buf_recv,sizeof(buf_recv),0) == 0)
  {
   printf("recv failed:%d\n",WSAGetLastError());
   exit(0);
  }
  printf("recv data from server:%s\n",buf_recv);

closesocket(client); //关闭套接字
WSACleanup();   //关闭套接字库
}
}