1.c

#include <myhead.h>
#define IP "192.168.60.45"
#define PORT 6666
#define BACKLOG 100
void fun(int sss)
{
	if(sss==SIGCHLD)
	{
		while(waitpid(-1,NULL,0)>0);
	}

}
int main(int argc, const char *argv[])
{
	//1.捕获子进程退出时的信号
	if(signal(SIGCHLD，fun)==SIG_ERR)
	{
		perror("signal");
		return -1;
	}
	//2.创建TCP类型的套接字
	int oldfd = socket(AF_INET,SOCK_STREAM,0);
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//3.端口号快速复用
	int n =1;
	if(setsockopt(oldfd,SOL_SOCKET,SO_REUSEADDR,&n,sizeof(n))==-1)
	{
		perror("setsockopt");
		return -1;
	}
	printf("端口号快速复用成功\n");

	//4.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");
	}

	//5.监听
	if(listen(oldfd,BACKLOG)==-1)
	{
		perror("listen");
		return -1;
	}
	struct sockaddr_in client;
	socklen_t client_len = sizeof(client);
	while(1)
	{
		//5.接受客户端连接
		int newfd = accept(oldfd,(struct sockaddr *)&client,&client_len);
		printf("%s发来连接请求\n",inet_ntoa(client.sin_addr));
		pid_t pid = fork();//创建子进程
		if(pid>0)
		{
			close(newfd);//父进程监听关闭新的描述符，父进程只需要监听
		}
		else if(pid==0)
		{
			close(oldfd);//关闭旧的描述符，子进程只需要数据收发即可
			while(1)
			{
				int len = recv(newfd,buff,sizeof(buff),0);
				if(len==0)
				{
					printf("客户端退出\n");
					break;
				}
				printf("客户端%s发来消息：%s\n",inet_ntoa(client.sin_addr).buff);
				strcat(buff,inet_ntoa(client.sin_addr));
				send(newfd,buff,sizeof(buff),0);
			}
			exit(0);
		}
		else
		{
			perror("fork");
			return -1;
		}
	}

	
	return 0;
}

2.c

#include <myhead.h>
#define IP "192.168.110.43"
#define PORT 8888
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.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;
	}
	//3.数据收发
	char buff[1024];
	while(1)
	{
		fgets(buff,sizeof(buff),stdin);//键盘输入字符串
		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("接受服务器消息:%s\n",buff);
	}
	close(oldfd);
	return 0;
}