socket网络编程之一:客户端和服务器端接口函数

 以下为winsock。

 1. socket网络编程分为客户端和服务器端,客户端发送请求,服务器端进行应答;

     建立连接时,服务器端绑定端口监听(bind&listen),客户端发送连接请求(connect),然后服务器端接受请求accept,至此客户端和服务器端可以收发消息。

     需要注意:

         1)创建socket前需要调用WSAStartup,对socket进行初始化。

         2)服务器端的accept函数,第三个参数addrlen既是输出,也是输入参数,所以需要有初值sizeof(sockaddr);

           accept(SOCKET s, struct sockaddr FAR * addr,int FAR * addrlen);

 

 2. 客户端的几个API:

         初始化socket:

                 wVersionRequested = MAKEWORD( 2, 0 );  
                 WSAStartup(wVersionRequested , &wsaData);

 

         创建socket:

              fd = socket(AF_INET,SOCK_STREAM,0);

 

         连接服务器:

              memset(&serverAddr,0,sizeof(serverAddr));
              serverAddr.sin_family = AF_INET;
              serverAddr.sin_port = htons(800);
              serverAddr.sin_addr.S_un.S_addr = inet_addr("192.168.0.22");


              connfd = connect(clientfd,(sockaddr *)&serverAddr,sizeof(sockaddr));

 

         发送消息:

              send(fd,pBuf,10,0);

 

         关闭socket:

              closesocket(clientfd);

 

  3.服务器端的几个API:

 

         初始化socket:

                 wVersionRequested = MAKEWORD( 2, 0 );  
                 WSAStartup(wVersionRequested , &wsaData);

 

         创建socket:

              fd = socket(AF_INET,SOCK_STREAM,0);

 

         绑定端口bind():

             memset(&serverAddr,0,sizeof(serverAddr));
             serverAddr.sin_family = AF_INET;
             serverAddr.sin_port = htons(800);
             serverAddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);

             bind(serverfd,(sockaddr *)&serverAddr,sizeof(sockaddr));

         监听端口listen:

             listen(serverfd,1024);


              connfd = connect(clientfd,(sockaddr *)&serverAddr,sizeof(sockaddr));

 

         接受连接accept:

                addrLen = sizeof(sockaddr); //需注意,addrLen是输入输入函数,必须先赋值再传入accept。
                connfd = accept(serverfd,(sockaddr *)&clientAddr,&addrLen);

 

         接收消息recv:

               recv(connfd,buf,100,0); //此处socket用的是connfd.

 

         关闭socket:

              closesocket(fd);                  

 

 

4.客户端程序:

#include <winsock2.h>
#include <stdio.h>


#pragma   comment(lib,   "ws2_32.lib ")
int main()
{
    int clientfd=0;
    int connfd =0;
    int ret =0;
    struct sockaddr_in  serverAddr;

    WORD wVersionRequested;
    WSADATA   wsaData;


    wVersionRequested = MAKEWORD( 2, 0 );  
    if (WSAStartup(wVersionRequested , &wsaData)!=0) 
   { 
       printf("Winsock Initialization failed./n");
       exit(0); 
   };

   clientfd = socket(AF_INET,SOCK_STREAM,0);
   if(clientfd <0)
   {
        printf("/r/ncreate socket error: %d",clientfd);
        return -1;
   }
   else
   {
       printf("/r/ncreate socket success,socket: %d",clientfd);
   }

   memset(&serverAddr,0,sizeof(serverAddr));
   serverAddr.sin_family = AF_INET;
   serverAddr.sin_port = htons(800);
   serverAddr.sin_addr.S_un.S_addr = inet_addr("192.168.0.22");


   connfd = connect(clientfd,(sockaddr *)&serverAddr,sizeof(sockaddr));
   if(connfd < 0 )
   {
       printf("/r/nconnect socket fail,connfd: %d/r/n",connfd);
       return -1;
   }
   else
   {
       printf("/r/nconnect socket success,connfd: %d",connfd);
   }

   //sendto(clientfd,pBuf,ucLen,(sockaddr *)&serverAddr,sizeof(sockaddr));
   char pBuf[10] = "123456789";
   send(clientfd,pBuf,10,0);
    
 
   closesocket(clientfd);

   return 0;
}

 

5.服务器端程序:

#include <winsock2.h>
#include <stdio.h>


#pragma   comment(lib,   "ws2_32.lib ")
int main()
{
    int serverfd=0;
    int connfd =0;
    int ret =0;
    struct sockaddr_in  serverAddr;
    struct sockaddr_in  clientAddr;
    int addrLen = 0;
    char buf[100];
    char ucLen;

    WORD wVersionRequested;
    WSADATA   wsaData;


    wVersionRequested = MAKEWORD( 2, 0 );     

    if (WSAStartup(wVersionRequested , &wsaData)!=0) 
    { 
        printf("Winsock Initialization failed./n");
        exit(0); 
    };

    serverfd = socket(AF_INET,SOCK_STREAM,0);
    if(serverfd <0)
    {
        printf("/r/ncreate socket error: %d",serverfd);
        return -1;
    }
    else
    {
        printf("/r/ncreate socket success,socket: %d",serverfd);
    }

    memset(&serverAddr,0,sizeof(serverAddr));
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(800);
    serverAddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);

    if(bind(serverfd,(sockaddr *)&serverAddr,sizeof(sockaddr)) < 0)
    {
        printf("/r/nbind socket fail,serverfd: %d/r/n",serverfd);
        return -1;
    }

    if(listen(serverfd,1024) < 0)
    {
         printf("/r/nbind socket fail,serverfd: %d/r/n",serverfd);
         return -1;
    }

    do
    {
        addrLen = sizeof(sockaddr);
        connfd = accept(serverfd,(sockaddr *)&clientAddr,&addrLen);
        if(addrLen != 0 )
        {
            printf("/r/naccept socket success,/n/rconnfd: %u,clientIp:%s,clientPort:%u",
            connfd,(inet_ntoa)(clientAddr.sin_addr),clientAddr.sin_port);
        }

        recv(connfd,buf,100,0);
        printf("recv data: %s",buf);   
    }while(1);

    closesocket(serverfd);

    return 0;
}

 

6.参考书籍:

    《深入理解计算机系统》十二章:网络编程

posted @ 2016-09-22 02:24  Anzhongliu  阅读(246)  评论(0编辑  收藏  举报