实验四

1.
查看主机名hostname

time_server1.c

#include <netinet/in.h> // for sockaddr_in
#include <sys/types.h> // for socket
#include <sys/socket.h> // for socket
#include <stdio.h> // for printf
#include <stdlib.h> // for exit
#include <string.h> // for bzero
#include <unistd.h> // for fork
#include <sys/signal.h> // for signal
#include <sys/wait.h> // for wait
#include <time.h>
#include <arpa/inet.h>
#define HELLO_WORLD_SERVER_PORT 6666
#define LENGTH_OF_LISTEN_QUEUE 20
#define BUFFER_SIZE 1024
void reaper(int sig)
{
int status;
//调用wait3读取子进程的返回值,使zombie状态的子进程彻底释放
while(wait3(&status,WNOHANG,(struct rusage*)0) >=0)
;
}
int main(int argc, char **argv)
{
//设置一个socket地址结构server_addr,代表服务器internet地址, 端口
struct sockaddr_in server_addr;
bzero(&server_addr,sizeof(server_addr)); //把一段内存区的内容全部设置为0
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = htons(INADDR_ANY);
server_addr.sin_port = htons(HELLO_WORLD_SERVER_PORT);

time_t t;

//创建用于internet的流协议(TCP)socket,用server_socket代表服务器socket
int server_socket = socket(AF_INET,SOCK_STREAM,0);
if( server_socket < 0)
{
printf("Create Socket Failed! ");
exit(1);
}

//把socket和socket地址结构联系起来
if( bind(server_socket,(struct sockaddr*)&server_addr,sizeof(server_addr)))
{
printf("Server Bind Port : %d Failed! ", HELLO_WORLD_SERVER_PORT);
exit(1);
}

//server_socket用于监听
if ( listen(server_socket, LENGTH_OF_LISTEN_QUEUE) )
{
printf("Server Listen Failed!");
exit(1);
}
//通知操作系统,当收到子进程的退出信号(SIGCHLD)时,执行reaper函数,释放zombie状态的进程
(void)signal(SIGCHLD,reaper);

while (1) //服务器端要一直运行
{
//定义客户端的socket地址结构client_addr
struct sockaddr_in client_addr;
socklen_t length = sizeof(client_addr);

//接受一个到server_socket代表的socket的一个连接
//如果没有连接请求,就等待到有连接请求--这是accept函数的特性
//accept函数返回一个新的socket,这个socket(new_server_socket)用于同连接到的客户的通信
//new_server_socket代表了服务器和客户端之间的一个通信通道
//accept函数把连接到的客户端信息填写到客户端的socket地址结构client_addr中

int new_server_socket = accept(server_socket,(struct sockaddr*)&client_addr,&length);
if ( new_server_socket < 0)
{
printf("Server Accept Failed! ");
break;
}
int child_process_pid = fork(); //fork()后,子进程是主进程的拷贝
//在主进程和子进程中的区别是fork()的返回值不同.
if(child_process_pid == 0 )//如果当前进程是子进程,就执行与客户端的交互
{
t=time(NULL);
close(server_socket); //子进程中不需要被复制过来的server_socket
char buffer[BUFFER_SIZE];
bzero(buffer, BUFFER_SIZE);
//strcpy(buffer,"20181217实现");
strcat(buffer," "); //C语言字符串连接

//发送buffer中的字符串到new_server_socket,实际是给客户端
send(new_server_socket,buffer,BUFFER_SIZE,0);
printf("服务器实现者学号：20181217 ");

printf("当前时间： %s ",ctime(&t));
send(new_server_socket,(void *)&t,sizeof(time_t),0);

bzero(buffer,BUFFER_SIZE);
//接收客户端发送来的信息到buffer中
length = recv(new_server_socket,buffer,BUFFER_SIZE,0);
if (length < 0)
{
printf("Server Recieve Data Failed! ");
exit(1);
}
printf(" %s ",buffer);
//关闭与客户端的连接
close(new_server_socket);
exit(0);
}
else if(child_process_pid > 0) //如果当前进程是主进程
close(new_server_socket); //主进程中不需要用于同客户端交互的new_server_socket
}
//关闭监听用的socket
close(server_socket);
return 0;
}

time_clnt1.c

#include <netinet/in.h> // for sockaddr_in
#include <sys/types.h>    // for socket
#include <sys/socket.h>    // for socket
#include <stdio.h>        // for printf
#include <stdlib.h>        // for exit
#include <string.h>        // for bzero
#include <time.h>
#define HELLO_WORLD_SERVER_PORT    6666 
#define BUFFER_SIZE 1024
void talk_to_server(char ** argv)
{
    //设置一个socket地址结构client_addr,代表客户机internet地址, 端口
    struct sockaddr_in client_addr;
    bzero(&client_addr,sizeof(client_addr)); //把一段内存区的内容全部设置为0
    client_addr.sin_family = AF_INET;    //internet协议族
    client_addr.sin_addr.s_addr = htons(INADDR_ANY);//INADDR_ANY表示自动获取本机地址
    client_addr.sin_port = htons(0);    //0表示让系统自动分配一个空闲端口
    //创建用于internet的流协议(TCP)socket,用client_socket代表客户机socket
    int client_socket = socket(AF_INET,SOCK_STREAM,0);
    time_t t;
    if( client_socket < 0)
    {
        printf("Create Socket Failed!
");
        exit(1);
    }
    //把客户机的socket和客户机的socket地址结构联系起来
    if( bind(client_socket,(struct sockaddr*)&client_addr,sizeof(client_addr)))
    {
        printf("Client Bind Port Failed!
"); 
        exit(1);
    }
    //设置一个socket地址结构server_addr,代表服务器的internet地址, 端口
    struct sockaddr_in server_addr;
    bzero(&server_addr,sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    if(inet_aton(argv[1],&server_addr.sin_addr) == 0) //服务器的IP地址来自程序的参数
    {
        printf("Server IP Address Error!
");
        exit(1);
    }
    server_addr.sin_port = htons(HELLO_WORLD_SERVER_PORT);
    socklen_t server_addr_length = sizeof(server_addr);
    //向服务器发起连接,连接成功后client_socket代表了客户机和服务器的一个socket连接
    if(connect(client_socket,(struct sockaddr*)&server_addr, server_addr_length) < 0)
    {
        printf("Can Not Connect To %s!
",argv[1]);
        exit(1);
    }
    char buffer[BUFFER_SIZE];
    bzero(buffer,BUFFER_SIZE);
    //从服务器接收数据到buffer中
    int length = recv(client_socket,buffer,BUFFER_SIZE,0);
    if(length < 0)
    {
        printf("Recieve Data From Server %s Failed!
", argv[1]);
        exit(1);
    }
    printf("From Server %s :	%s
",argv[1],buffer);
    length = recv(client_socket,(void *)&t,sizeof(time_t),0);
    if(length < 0)
    {
        printf("Recieve Data From Server %s Failed!
", argv[1]);
        exit(1);
    }
    printf("当前时间： %s 
",ctime(&t));
    bzero(buffer,BUFFER_SIZE);
    //strcpy(buffer,"Thanks!");
    //向服务器发送buffer中的数据
    send(client_socket,buffer,BUFFER_SIZE,0);
    //关闭socket
    close(client_socket);
}
int main(int argc, char **argv)
{
    if (argc != 2)
    {
        printf("Usage: .\%s ServerIPAddress
",argv[0]);
        exit(1);
    }
    talk_to_server(argv);
    return 0;
}

运行截图：

 远程登录华为云服务器以及server端：

 本地wsl客户端：

 2.echo

echoserver1.c

#include <netinet/in.h> // for sockaddr_in
#include <sys/types.h>    // for socket
#include <sys/socket.h>    // for socket
#include <stdio.h>        // for printf
#include <stdlib.h>        // for exit
#include <string.h>        // for bzero
#include <unistd.h>        // for fork
#include <sys/signal.h> // for signal
#include <sys/wait.h>    // for wait
#include <time.h>
#include <arpa/inet.h>
#define HELLO_WORLD_SERVER_PORT    6666 
#define LENGTH_OF_LISTEN_QUEUE  20
#define BUFFER_SIZE 1024
void reaper(int sig)
{
    int status;
    //调用wait3读取子进程的返回值,使zombie状态的子进程彻底释放
    while(wait3(&status,WNOHANG,(struct rusage*)0) >=0)
        ;
}
int main(int argc, char **argv)
{
    //设置一个socket地址结构server_addr,代表服务器internet地址, 端口
    struct sockaddr_in server_addr;
    bzero(&server_addr,sizeof(server_addr)); //把一段内存区的内容全部设置为0
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htons(INADDR_ANY);
    server_addr.sin_port = htons(HELLO_WORLD_SERVER_PORT);
    char f[100];
    pid_t pid1;
    //time_t t;
    
    //创建用于internet的流协议(TCP)socket,用server_socket代表服务器socket
    int server_socket = socket(AF_INET,SOCK_STREAM,0);
    if( server_socket < 0)
    {
        printf("Create Socket Failed!
");
        exit(1);
    }
    
    //把socket和socket地址结构联系起来
    if( bind(server_socket,(struct sockaddr*)&server_addr,sizeof(server_addr)))
    {
        printf("Server Bind Port : %d Failed!
", HELLO_WORLD_SERVER_PORT); 
        exit(1);
    }
    
    //server_socket用于监听
    if ( listen(server_socket, LENGTH_OF_LISTEN_QUEUE) )
    {
        printf("Server Listen Failed!"); 
        exit(1);
    }
    //通知操作系统,当收到子进程的退出信号(SIGCHLD)时,执行reaper函数,释放zombie状态的进程
    (void)signal(SIGCHLD,reaper);
    
    while (1) //服务器端要一直运行
    {
        //定义客户端的socket地址结构client_addr
        struct sockaddr_in client_addr;
        socklen_t length = sizeof(client_addr);
        //接受一个到server_socket代表的socket的一个连接
        //如果没有连接请求,就等待到有连接请求--这是accept函数的特性
        //accept函数返回一个新的socket,这个socket(new_server_socket)用于同连接到的客户的通信
        //new_server_socket代表了服务器和客户端之间的一个通信通道
        //accept函数把连接到的客户端信息填写到客户端的socket地址结构client_addr中
        int new_server_socket = accept(server_socket,(struct sockaddr*)&client_addr,&length);
        if ( new_server_socket < 0)
        {
            printf("Server Accept Failed!
");
            break;
        }
        int child_process_pid = fork(); //fork()后,子进程是主进程的拷贝
        //在主进程和子进程中的区别是fork()的返回值不同.
        if(child_process_pid == 0 )//如果当前进程是子进程,就执行与客户端的交互
        {
            close(server_socket); //子进程中不需要被复制过来的server_socket
            char buffer[BUFFER_SIZE];
            char buffer1[BUFFER_SIZE];
            char a[100]="服务器进程 ";
            
            bzero(buffer, BUFFER_SIZE);         
            
            //发送buffer中的字符串到new_server_socket,实际是给客户端
            //send(new_server_socket,buffer,BUFFER_SIZE,0);
            printf("服务器实现者学号：20181217
");
            bzero(buffer,BUFFER_SIZE);
            //接收客户端发送来的信息到buffer中
            length = recv(new_server_socket,buffer,BUFFER_SIZE,0);
            if (length < 0)
            {
                printf("Server Recieve Data Failed!
");
                exit(1);
            }
            printf("
客户端输入内容为%s
",buffer);//打印出buffer
            sprintf(f,"%d",getpid());//f：将数字pid转化成字符串   
            strcpy(buffer1,strcat(strcat(strcat(a,f)," 20181217 陈少卿 echo:"),buffer));//复制到buffer1中
            send(new_server_socket,buffer1,BUFFER_SIZE,0);//把buffer1发送给客户端
            //关闭与客户端的连接
            close(new_server_socket); 
            exit(0);         
        }
        else if(child_process_pid > 0)     //如果当前进程是主进程 
            close(new_server_socket);    //主进程中不需要用于同客户端交互的new_server_socket
    }
    //关闭监听用的socket
    close(server_socket);
    return 0;
}

echoclnt1.c

#include <netinet/in.h> // for sockaddr_in
#include <sys/types.h> // for socket
#include <sys/socket.h> // for socket
#include <stdio.h> // for printf
#include <stdlib.h> // for exit
#include <string.h> // for bzero
#include <time.h>
#define HELLO_WORLD_SERVER_PORT 6666
#define BUFFER_SIZE 1024

void talk_to_server(char ** argv)
{
//设置一个socket地址结构client_addr,代表客户机internet地址, 端口
struct sockaddr_in client_addr;
bzero(&client_addr,sizeof(client_addr)); //把一段内存区的内容全部设置为0
client_addr.sin_family = AF_INET; //internet协议族
client_addr.sin_addr.s_addr = htons(INADDR_ANY);//INADDR_ANY表示自动获取本机地址
client_addr.sin_port = htons(0); //0表示让系统自动分配一个空闲端口
//创建用于internet的流协议(TCP)socket,用client_socket代表客户机socket
int client_socket = socket(AF_INET,SOCK_STREAM,0);
time_t t;
if( client_socket < 0)
{
printf("Create Socket Failed! ");
exit(1);
}
//把客户机的socket和客户机的socket地址结构联系起来
if( bind(client_socket,(struct sockaddr*)&client_addr,sizeof(client_addr)))
{
printf("Client Bind Port Failed! ");
exit(1);
}

//设置一个socket地址结构server_addr,代表服务器的internet地址, 端口
struct sockaddr_in server_addr;
bzero(&server_addr,sizeof(server_addr));
server_addr.sin_family = AF_INET;
if(inet_aton(argv[1],&server_addr.sin_addr) == 0) //服务器的IP地址来自程序的参数
{
printf("Server IP Address Error! ");
exit(1);
}
server_addr.sin_port = htons(HELLO_WORLD_SERVER_PORT);
socklen_t server_addr_length = sizeof(server_addr);
//向服务器发起连接,连接成功后client_socket代表了客户机和服务器的一个socket连接
if(connect(client_socket,(struct sockaddr*)&server_addr, server_addr_length) < 0)
{
printf("Can Not Connect To %s! ",argv[1]);
exit(1);
}

char buffer[BUFFER_SIZE];
//向服务器发送buffer中的数据
fgets(buffer,BUFFER_SIZE,stdin);
printf("读入的buffer为%s",buffer);
//发送给客户端
send(client_socket,buffer,BUFFER_SIZE,0);

bzero(buffer,BUFFER_SIZE);
//从服务器接收数据到buffer中
int length = recv(client_socket,buffer,BUFFER_SIZE,0);
if(length < 0)
{
printf("Recieve Data From Server %s Failed! ", argv[1]);
exit(1);
}
printf("From Server %s : %s ",argv[1],buffer);
//length = recv(client_socket,(void *)&t,sizeof(time_t),0);
//if(length < 0)
//{
// printf("Recieve Data From Server %s Failed! ", argv[1]);
// exit(1);
//}
//printf("当前时间： %s ",ctime(&t));
//bzero(buffer,BUFFER_SIZE);
//strcpy(buffer,"Thanks!");
//向服务器发送buffer中的数据
//send(client_socket,buffer,BUFFER_SIZE,0);
//关闭socket
close(client_socket);
}
int main(int argc, char **argv)
{
if (argc != 2)
{
printf("Usage: .\%s ServerIPAddress ",argv[0]);
exit(1);
}
talk_to_server(argv);

return 0;
}

运行结果：（三个客户端进行访问）

1.远程连接华为云，并运行echo服务器程序