8.19（Day 1）网络编程 ---＞TCP/IP

1.服务器可以循环接收客户端的数据；

2.当客户端退出后， 服务器阻塞等待下一个客户端的连接，而后继续通信；

代码如下：

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

typedef struct sockaddr_in addr_in_t;
typedef struct sockaddr addr_t;
typedef struct sockaddr_un addr_un_t;
int main(int argc, const char *argv[])
{
	int sockfd = socket(AF_INET,SOCK_STREAM,0);
	if(sockfd < 0)
	{
		perror("sockfd is error:");
		return -1;
	}
	struct sockaddr_in saddr;
	saddr.sin_family = AF_INET;
	saddr.sin_port = htons(8989);
	saddr.sin_addr.s_addr = inet_addr("192.168.132.128");

	if(bind(sockfd,(struct sockaddr *)&saddr,sizeof(saddr)) < 0)
	{
		perror("bind is error:");
		return -1;
	}
	if(listen(sockfd,5) < 0)
	{
		perror("listen is error:");
		return -1;
	}
	printf("Next is accept\n");
		int acceptfd = accept(sockfd,NULL,NULL);
		char stu[128];
	while(1)
	{
		int res = recv(acceptfd,stu,sizeof(stu),0);
		if(res == 0)
		{
			acceptfd = accept(sockfd,NULL,NULL);
			res = recv(acceptfd,stu,sizeof(stu),0);
			printf("client is exit:\n");
		}
		else if(res < 0)
		{
			perror("error:");
			return -1;
		}
		else 
		{
			printf("client is:%s\n",stu);
		}
	}
	return 0;
}

实现结果：

3.当有客户端连接时， 服务器端 打印客户端的IP 和 Port信息；

代码如下：

运行结果：

4.将代码的 send 和 recv 改为 write 和 read， 测试一下效果；

5.利用argv[ ] 采用终端输入的方式， 输入IP 和 Port ，从而bind绑定;

整体代码：

服务端代码：

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

typedef struct sockaddr_in addr_in_t;
typedef struct sockaddr addr_t;
typedef struct sockaddr_un addr_un_t;
int main(int argc, const char *argv[])
{
	int sockfd = socket(AF_INET,SOCK_STREAM,0);
	if(sockfd < 0)
	{
		perror("sockfd is error:");
		return -1;
	}
	struct sockaddr_in saddr,sty;

	saddr.sin_family = AF_INET;
	saddr.sin_port = htons(atoi(argv[1]));
	saddr.sin_addr.s_addr = inet_addr(argv[2]);

	if(bind(sockfd,(struct sockaddr *)&saddr,sizeof(saddr)) < 0)
	{
		perror("bind is error:");
		return -1;
	}
	if(listen(sockfd,5) < 0)
	{
		perror("listen is error:");
		return -1;
	}
	printf("Next is accept\n");
	sty.sin_family = AF_INET;

	int len = sizeof(sty);
	int acceptfd = accept(sockfd,(struct sockaddr *)&sty,&len);
	int a = ntohs(sty.sin_port);
	printf("a = %d\n", a);
	char* b = { inet_ntoa(sty.sin_addr)};
	printf("b = %s\n", b);

	char stu[128];
	while(1)
	{
		int res = read(acceptfd,stu,sizeof(stu));
		if(res == 0)
		{
			printf("client is exit:\n");
		}
		else if(res < 0)
		{
			perror("error:");
			return -1;
		}
		else 
		{
			printf("client is:%s\n",stu);
		}
	}
	close(sockfd);
	close(acceptfd);
	return 0;
}

客户端代码：

#include 
#include           /* See NOTES */
#include 
#include 
#include  /* superset of previous */
#include 
#include 
#include 
#include 

int main(int argc, char const *argv[])
{
    //1. 创建套接字
    int sockfd = socket(AF_INET,SOCK_STREAM,0);
    if(sockfd < 0)
    {
        perror("socket is err:");
        return -1;
    }
    struct sockaddr_in caddr;
    caddr.sin_family = AF_INET;
    //argv[1] 要写 服务器的Port
    caddr.sin_port = htons(atoi(argv[1]));
    //argv[2] 要写 服务器的IP
    caddr.sin_addr.s_addr = inet_addr(argv[2]);

    //2.主动连接  -  连接 caddr 的成员 - IP  Port
    if(connect(sockfd,(struct sockaddr *)&caddr,sizeof(caddr)) < 0)
    {
        perror("connect is err:");
        return -1;
    }

    char buf[128];
    //3.通信
    while(1)
    {
        fgets(buf,sizeof(buf),stdin);
        if(buf[strlen(buf)-1] == '\n');
          buf[strlen(buf) -1] = '\0';
        //发送   
        send(sockfd,buf,sizeof(buf),0);

    }


    close(sockfd);
    return 0;
}