TCP的server和client的实现

window上调试过的网络编程，把注释的一些代码放开并稍加修改可以在linux上用

// networkserver.cpp : Defines the entry point for the console application.
//
/******* 服务器程序  (server.c) ************/
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
//#include <unistd.h>
//#include <netdb.h>
//#include <sys/socket.h>
//#include <netinet/in.h>
#include <sys/types.h>
//#include <arpa/inet.h>
#include "stdafx.h"
#include< windows.h >
#include< winsock.h >
#pragma comment( lib, "ws2_32.lib" )

int _tmain(int argc, _TCHAR* argv[])
{
        int sockfd,new_fd;
        struct sockaddr_in server_addr;
        struct sockaddr_in client_addr;
        int sin_size;
		int portnumber = 8889;
        char hello[]="Hello! Are You Fine?\n";
		WSADATA WSAData;
		/*
        if(argc!=2)
        {
                fprintf(stderr,"Usage:%s portnumber\a\n",argv[0]);
                exit(1);
        }

        if((portnumber=atoi((const char*)argv[1]))<0)
        {
                fprintf(stderr,"Usage:%s portnumber\a\n",argv[0]);
                exit(1);
        }
		*/
		if( WSAStartup( MAKEWORD( 1, 1 ), &WSAData ) )//初始化
		{
		printf( "initializationing error!\n" );
		WSACleanup( );
		exit( 0 );
		}

        /* 服务器端开始建立socket描述符 */
        if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)  
        {
                fprintf(stderr,"Socket error:%s\n\a",strerror(errno));
                exit(1);
        }
		

        /* 服务器端填充 sockaddr结构  */ 
        //bzero(&server_addr,sizeof(struct sockaddr_in));
		memset(&server_addr,0,sizeof(struct sockaddr_in));
        server_addr.sin_family=AF_INET;
        server_addr.sin_addr.s_addr=htonl(INADDR_ANY);
        server_addr.sin_port=htons(portnumber);

        /* 捆绑sockfd描述符  */ 
        if(bind(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1)
        {
                fprintf(stderr,"Bind error:%s\n\a",strerror(errno));
                exit(1);
        }

        /* 监听sockfd描述符  */
        if(listen(sockfd,5)==-1)
        {
                fprintf(stderr,"Listen error:%s\n\a",strerror(errno));
                exit(1);
        }

        while(1)
        {
                /* 服务器阻塞,直到客户程序建立连接  */
                sin_size=sizeof(struct sockaddr_in);
                if((new_fd=accept(sockfd,(struct sockaddr *)(&client_addr),&sin_size))==-1)
                {
                        fprintf(stderr,"Accept error:%s\n\a",strerror(errno));
                        exit(1);
                }

                fprintf(stderr,"Server get connection from %s\n",
                inet_ntoa(client_addr.sin_addr));
                //if(write(new_fd,hello,strlen(hello))==-1)
				if(send( new_fd, hello, strlen( hello ), 0 ) == -1 )
                {
                        fprintf(stderr,"Write Error:%s\n",strerror(errno));
                        exit(1);
                }
                /* 这个通讯已经结束     */
                //close(new_fd);
				closesocket(new_fd);
                /* 循环下一个     */  
        }
        //close(sockfd);
		closesocket(sockfd);
        exit(0);
}

// networkclient.cpp : Defines the entry point for the console application.
//
/******* 客户端程序  client.c ************/
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
//#include <unistd.h>
//#include <netdb.h>
//#include <sys/socket.h>
//#include <netinet/in.h>
#include <sys/types.h>
//#include <arpa/inet.h>
#include "stdafx.h"
#include< windows.h >
#include< winsock.h >
#pragma comment( lib, "ws2_32.lib" )

int _tmain(int argc, _TCHAR* argv[])
{
        int sockfd;
		char buf[128];
        char buffer[1024];
        struct sockaddr_in server_addr;
        struct hostent *host;
		struct in_addr *a;
        int portnumber = 8889;
		int nbytes;
		char* tmp;
		WSADATA WSAData;
		/*
        if(argc!=3)
        {
                fprintf(stderr,"Usage:%s hostname portnumber\a\n",argv[0]);
                exit(1);
        }

        if((host=gethostbyname((const char*)argv[1]))==NULL)
        {
                fprintf(stderr,"Gethostname error\n");
                exit(1);
        }

        if((portnumber=atoi(argv[2]))<0)
        {
                fprintf(stderr,"Usage:%s hostname portnumber\a\n",argv[0]);
                exit(1);
        }
		*/
		if( WSAStartup( MAKEWORD( 1, 1 ), &WSAData ) )//初始化
		{
		printf( "initializationing error!\n" );
		WSACleanup( );
		exit( 0 );
		}
		if (argc == 1) {
		  printf("host: ");
		  fgets(buf, sizeof(buf), stdin);
		  if ((tmp = strchr(buf, '\n')) != NULL)
		   *tmp = '\0';
		  host = gethostbyname(buf);
		 }
		 else {
		  host = gethostbyname((const char*)argv[1]);
		 }
        /* 客户程序开始建立 sockfd描述符  */
        if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
        {
                fprintf(stderr,"Socket Error:%s\a\n",strerror(errno));
                exit(1);
        }

        /* 客户程序填充服务端的资料       */
        //bzero(&server_addr,sizeof(server_addr));
		memset(&server_addr,0,sizeof(server_addr));
        server_addr.sin_family=AF_INET;
        server_addr.sin_port=htons(portnumber);
        server_addr.sin_addr=*((struct in_addr *)host->h_addr);

        /* 客户程序发起连接请求         */ 
        if(connect(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1)
        {
                fprintf(stderr,"Connect Error:%s\a\n",strerror(errno));
                exit(1);
        }

        /* 连接成功了           */
        //if((nbytes=read(sockfd,buffer,1024))==-1)
		if((nbytes=recv(sockfd,buffer,1024,0))==-1)
        {
                fprintf(stderr,"Read Error:%s\n",strerror(errno));
                exit(1);
        }
        buffer[nbytes]='\0';
        printf("I have received:%s\n",buffer);
        /* 结束通讯     */
        //close(sockfd);
		closesocket(sockfd);
		system("pause");
        exit(0);
}