网络编程 day4~day5.1——多点通信，域套接字

笔记脑图

作业：

1、将广播发送和接收端实现一遍，完成一个发送端发送信息，对应多个接收端接收信息实验。

接收端

#include <stdio.h>
#include <string.h>
#include <myhead.h>
#define IP "192.168.61.255"
#define PORT 6666
int main(int argc, const char *argv[])
{
	//创建
	int oldfd=socket(AF_INET,SOCK_DGRAM,0);
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//绑定
	struct sockaddr_in recv={
		.sin_family=AF_INET,
		.sin_port=htons(PORT),
		.sin_addr.s_addr=inet_addr(IP),
	};
	if(bind(oldfd,(struct sockaddr *)&recv,sizeof(recv))==-1)
	{
		perror("bind");
		return -1;
	}
	//接收
	char buff[1024];
	while(1)
	{
		recvfrom(oldfd,buff,sizeof(buff),0,NULL,NULL);
		printf("接收到%s发送来的消息:%s\n",inet_ntoa(recv.sin_addr),buff);
		if(strcmp(buff,"quit")==0)
		{
			printf("接收端退出\n");
			break;
		}
	}
	close(oldfd);
	return 0;
}

发送端

#include <stdio.h>
#include <string.h>
#include <myhead.h>
#define IP "192.168.61.255"
#define PORT 6666
int main(int argc, const char *argv[])
{
	//创建
	int oldfd=socket(AF_INET,SOCK_DGRAM,0);
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//允许广播
	int n=1;
	if(setsockopt(oldfd,SOL_SOCKET,SO_BROADCAST,&n,sizeof(n))==-1)
	{
		perror("setsockopt");
		return -1;
	}
	//结构体
	struct sockaddr_in send={
		.sin_family=AF_INET,
		.sin_port=htons(PORT),
		.sin_addr.s_addr=inet_addr(IP)
	};
	//
	char buff[1024];
	while(1)
	{
		bzero(buff,sizeof(buff));
		fgets(buff,sizeof(buff),stdin);
		buff[strlen(buff)-1]='\0';

		sendto(oldfd,buff,sizeof(buff),0,(struct sockaddr *)&send,sizeof(send));
		printf("发送成功\n");
		if(strcmp(buff,"quit")==0)
		{
			printf("发送端退出\n");
			break;
		}
	}
	close(oldfd);
	return 0;
}

2、使用多线程基于TCP协议的并发执行，一个服务器对应多个客户端实现通信实验。

服务器

#include <stdio.h>
#include <string.h>
#include <myhead.h>
#define IP "192.168.60.44"
#define PORT 6666
#define BACKLOG 1024
typedef struct 
{
	struct sockaddr_in client;
	int newfd;
}stu;
void *fun(void *sss)
{
	int newfd=((stu *)sss)->newfd;
	struct sockaddr_in client=((stu *)sss)->client;
	printf("%s发来消息\n",inet_ntoa(client.sin_addr));

	char buff[1024];
	while(1)
	{
		int len=recv(newfd,buff,sizeof(buff),0);
		if(len==0)
		{
			printf("客户端退出\n");
			break;
		}
		printf("收到来自%s的消息:%s\n",inet_ntoa(client.sin_addr),buff);
		strcat(buff,"1973");
		send(newfd,buff,sizeof(buff),0);
	}
	pthread_exit(NULL);
}
int main(int argc, const char *argv[])
{
	int oldfd=socket(AF_INET,SOCK_STREAM,0);
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//
	struct sockaddr_in server={
		.sin_family=AF_INET,
		.sin_port=htons(PORT),
		.sin_addr.s_addr=inet_addr(IP),
	};
	if(bind(oldfd,(struct sockaddr *)&server,sizeof(server))==-1)
	{
		perror("bind");
		return -1;
	}
	//
	if(listen(oldfd,BACKLOG)==-1)
	{
		perror("listen");
		return -1;
	}
	struct sockaddr_in client;
	socklen_t client_len=sizeof(client);
	while(1)
	{
		int newfd=accept(oldfd,(struct sockaddr *)&client,&client_len);
		
		stu a;
		a.newfd=newfd;
		a.client=client;

		pthread_t tid;
		tid=pthread_create(&tid,NULL,fun,&a);
		if(tid==-1)
		{
			perror("pthread_create");
			return -1;
		}
		pthread_detach(tid);
	}
	return 0;
}

客户端

#include <stdio.h>
#include <string.h>
#include <myhead.h>
#define IP "192.168.60.44"
#define PORT 6666
int main(int argc, const char *argv[])
{
	//创建
	int oldfd=socket(AF_INET,SOCK_STREAM,0);
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//连接服务器
	struct sockaddr_in server={
		.sin_family=AF_INET,
		.sin_port=htons(PORT),
		.sin_addr.s_addr=inet_addr(IP),
	};
	if(connect(oldfd,(struct sockaddr *)&server,sizeof(server))==-1)
	{
		perror("connect");
		return -1;
	}
	//循环收发
	char buff[1024];
	while(1)
	{
		fgets(buff,sizeof(buff),stdin);
		buff[strlen(buff)-1]='\0';
		send(oldfd,buff,sizeof(buff),0);
		int len=recv(oldfd,buff,sizeof(buff),0);
		if(len==0)
		{
			printf("服务器意外退出\n");
			break;
		}
		printf("接收服务器的消息：%s\n",buff);
	}
	//关闭
	close(oldfd);
	return 0;
}