《UNIX网络编程》 1

1、安装 daytime 服务：

apt-get install xinetd

chmod 777 /etc/xinetd.d/daytime

vim /etc/xinetd.d/daytime

把两个 disable = yes ,改成 disable = no

/etc/init.d/xinetd restart

 

2、timeserver.cpp:

#include <time.h>

#include <netinet/in.h>

#include <string.h>

#include <stdio.h>

#include <unistd.h>



#define LISTENQ 1024

int main(int argc, char** argv)

{

    int listenfd,connfd;

    sockaddr_in servaddr;

    char buff[1024];

    time_t ticks;



    listenfd = socket(AF_INET,SOCK_STREAM,0);

    bzero(&servaddr,sizeof(servaddr));

    servaddr.sin_family = AF_INET;

    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);

    servaddr.sin_port = htons(2013);



    bind(listenfd,(sockaddr*)&servaddr,sizeof(servaddr));

    listen(listenfd,LISTENQ);

    for(;;)

    {   

        connfd = accept(listenfd,(sockaddr*)NULL,NULL);

        ticks = time(NULL);

        snprintf(buff,sizeof(buff),"%.24s\r\n",ctime(&ticks));

        write(connfd,buff,strlen(buff));    //#include <unistd.h>

        close(connfd);

    }   

}

 

3、timeclient.cpp:

#include <iostream>

#include <netinet/in.h>

#include <string.h>

#include <arpa/inet.h>

#include <stdio.h>



int main(int argc, char **argv)

{

    int     sockfd,n;

    char    recvline[1024];

    sockaddr_in servaddr;       //#include <netinet/in.h>



    if(argc != 2)

    {   

        std::cout<<"usage: a.out <IP>"<<std::endl;

        return -1; 

    }   

    if((sockfd = socket(AF_INET,SOCK_STREAM,0)) < 0)    //#include <sys/socket.h>

    {   

        std::cout<<"socket error."<<std::endl;

        return -1; 

    }   

    bzero(&servaddr, sizeof(servaddr)); //#include <cstring>

    servaddr.sin_family = AF_INET;

    servaddr.sin_port = htons(2013);

    if(inet_pton(AF_INET,argv[1],&servaddr.sin_addr) <= 0)  // #include <arpa/inet.h>

    {   

        std::cout<<"inet_pton error"<<std::endl;

        return -1; 

    }   

    if(connect(sockfd, (sockaddr*)&servaddr,sizeof(servaddr)) < 0)  

    {   

        std::cout<<"connect error"<<std::endl;

        return -1; 

    }   

    while( (n = read(sockfd, recvline, 1023)) > 0)

    {   

        recvline[n] = 0;

        if(fputs(recvline, stdout) == EOF)  //#include <stdio.h>

        {   

            std::cout<<"fputs error"<<std::endl;

        }   

    }   

    if(n < 0)

    {   

        std::cout<<"read error"<<std::endl;

    }  

}