1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

#include <myhead.h>
//主线程负责监听客户端连接请求
//子线程负责数据收发
#define IP "192.168.60.77"
#define PORT 5555
#define BACKLOG 10
typedef struct
{
	struct sockaddr_in  client;
	int newfd;
}ZYJ;
void * fun(void *sss)

{
	int newfd=((ZYJ *)sss)->newfd;
	struct sockaddr_in client=((ZYJ*)sss)->client;
	char buff[1024];
	printf("%s发来信息\n",inet_ntoa(client.sin_addr));
	while(1)
	{
		bzero(buff,sizeof(buff));
		int len=recv(newfd,buff,sizeof(buff),0);
		if(len==0)
		{
			printf("客户端退出\n");
		}
		printf("收到消息：%s\n",buff);
		strcat(buff,"-1973");
		send(newfd,buff,sizeof(buff),0);
	}
	pthread_exit(NULL);//线程退出
}
int main(int argc, const char *argv[])
{
	//1.创建套接字
	int oldfd=socket(AF_INET,SOCK_STREAM,0);
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//2.绑定
	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;
	}
	//3.监听
	if(listen(oldfd,BACKLOG)==-1)
	{
		perror("listen");
		return -1;
	}
	struct sockaddr_in client;
	socklen_t client_len;
	while(1)
	{
		int newfd=accept(oldfd,(struct sockaddr*)&client,&client_len);
		ZYJ sb;
		sb.newfd=newfd;//结构体成员新描述符
		sb.client=client;//结构体成员客户端信息赋值

		pthread_t tid;
		tid=pthread_create(&tid,NULL,fun,&sb);
		if(tid==-1)
		{
			perror("thread_create");
			return -1;
		}
		pthread_detach(tid);//挂起线程由系统回收资源
	}
	return 0;
}

#include <myhead.h>
#define IP "192.168.60.77"
#define PORT 5555
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(connect(oldfd,(struct sockaddr *)&server,sizeof(server))==-1)
	{
		perror("connect");
		return -1;
	
	}
	//3.数据收发
	char buff[1024];
	while(1)
	{
		fgets(buff,sizeof(buff),stdin);
		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("接受服务器消息：%s\n",buff);
	}
	return 0;
}

2.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

#include <myhead.h>
#define IP "192.168.61.255"
#define PORT 5535
int main(int argc, const char *argv[])
{
	int oldfd=socket(AF_INET,SOCK_DGRAM,0);
	int n=1;
	setsockopt(oldfd,SOL_SOCKET,SO_BROADCAST,&n,sizeof(n));
	printf("允许广播成功\n");
	//绑定
	struct sockaddr_in send={
		.sin_family=AF_INET,
		.sin_port=htons(PORT),
		.sin_addr.s_addr=inet_addr(IP)
	};
	/*
	if(bind(oldfd,(struct sockaddr *)&send,sizeof(send))==-1)
	{
		perror("bind");
		return -1;
	}
	*/
	printf("绑定成功");
	char buff[1024];
	while(1)//信息发送
	{
		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");
	}
	close(oldfd);
	return 0;
}

#include <myhead.h>
#define IP "192.168.61.255"
#define PORT 9999
int main(int argc, const char *argv[])
{
	int oldfd=socket(AF_INET,SOCK_DGRAM,0);
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//2.填充结构体
	struct sockaddr_in recv={
	.sin_family=AF_INET,
	.sin_port=htons(PORT),
	.sin_addr.s_addr=inet_addr(IP)
	};
	//3.绑定
	if(bind(oldfd,(struct sockaddr*)&recv,sizeof(recv))==-1)
	{
		perror("bind");
		return -1;
	}
	printf("绑定成功\n");
	char buff[1024];
	struct sockaddr_in ajin;
	socklen_t ajin_len=sizeof(ajin);
	while(1)
	{
		recvfrom(oldfd,buff,sizeof(buff),0,(struct sockaddr *)&ajin,&ajin_len);
		printf("接收到了%s的信息：%s\n",inet_ntoa(ajin.sin_addr),buff);
		//strcat(buff,"^_^");
		//sendto(oldfd,buff,sizeof(buff),0,(struct sockaddr*)&recv,sizeof(recv));
		//printf("转发成功\n");
	}
	close(oldfd);
	return 0;
}