day35：网编day2，TCP和UDP服务器和客户端的连接

TCP服务器

#include 

#define ERR_MSG(msg) do{fprintf(stderr,"__%d__\n",__LINE__);perror(msg);}while(0)
#define PORT 8888 //端口号，范围1024-49151
#define IP "192.168.115.105" 	//服务器的ip，点分十进制

int main(int argc, const char *argv[])
{
	//创建套接字文件socket
	int sfd;
	if((sfd = socket(AF_INET,SOCK_STREAM,0)) < 0)
	{
		ERR_MSG("socket");
		return -1;
	}
	printf("socket success  fd = %d\n",sfd);

	//填充地址结构体，给bind使用
	struct sockaddr_in sin;
	sin.sin_family 	= AF_INET;
	sin.sin_port 	= htons(PORT); //主机字节序转化成网络字节序
	sin.sin_addr.s_addr = inet_addr(IP); //本机IP
    //允许端口快速的被复用
    int reuse = 1;                                                            
    if(setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) < 0)
    {
        ERR_MSG("setsockopt");
        return -1;
    }
    printf("允许端口快速的被复用成功\n");	//与服务器IP和端口进行绑定bind

	if(bind(sfd,(struct sockaddr *)&sin,sizeof(sin)) == -1)
	{
		ERR_MSG("bind");
		return -1;
	}
	printf("bind success\n");

	//将套接字转化为监听状态listen
	if(listen(sfd,128) == -1)
	{
		ERR_MSG("listen");
		return -1;
	}
	printf("listen success\n");

	int newfd = -1;
	struct sockaddr_in cin;
	socklen_t addrlen = sizeof(cin);
	//获得连接成功后的套接字accept
	if((newfd = accept(sfd,(struct sockaddr *)&cin,&addrlen)) < 0)
	{
		ERR_MSG("accept");
		return -1;
	}
	printf("[%s:%d]客户端连接成功 newfd = %d\n",\
			inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd);
	char buf[128] = "";
	ssize_t sum=0;
	while(1)
	{
		bzero(buf,sizeof(buf));
		//接收
		sum=recv(newfd,buf,sizeof(buf),0);
		if(sum == -1)
		{
			ERR_MSG("recv");
			return -1;
		}
		else if(sum == 0)
		{
			printf("[%s:%d] 客户端下线 newfd = %d\n",\
					inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd);
			break;
		}
		printf("[%s:%d]newfd = %d : %s\n",\
				inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd,buf);
		//发送
		strcat(buf,">_<");
		if(send(newfd,buf,sizeof(buf),0) < 0)
		{
			ERR_MSG("send");
			return -1;
		}
		printf("send success\n");
	}

	//关闭文件
	close(newfd);
	if(close(sfd) < 0)
	{
		ERR_MSG("close");
		return -1;
	}
	printf("close success\n");
	return 0;
}

TCP客户端：

#include 
#define ERR_MSG(msg) do{fprintf(stderr,"__%d__\n",__LINE__);perror(msg);}while(0)
#define IP "192.168.115.105"
#define PORT 8888
int main(int argc, const char *argv[])
{
	//创建套接字
	int cfd;
	if((cfd = socket(AF_INET,SOCK_STREAM,0)) < 0)
	{
		ERR_MSG("socket");
		return -1;
	}
	printf("socket success fd = %d\n",cfd);
	//非必须绑定ip和端口号bind
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);
	//连接服务器connect
	if(connect(cfd,(struct sockaddr*)&sin,sizeof(sin)) < 0)
	{
		ERR_MSG("connect");
		return -1;
	}
	char buf[128] = "";

	while(1)
	{
		//发送
		fgets(buf,sizeof(buf),stdin);
		buf[strlen(buf)-1] = '\0';

		if(send(cfd,buf,sizeof(buf),0) < 0)
		{
			ERR_MSG("send");
			return -1;
		}
		
		bzero(buf,sizeof(buf));
		//接收
		ssize_t num = recv(cfd,buf,sizeof(buf),0);
		if(num < 0)
		{
			ERR_MSG("recv");
			return -1;
		}
		else if(0 == num)
		{
			printf("服务器已下线 fd = %d\n",cfd);
			break;
		}
		printf("cfd = %d: %s\n",cfd,buf);
	}
	//关闭文件描述符
	if(close(cfd) < 0)
	{
		ERR_MSG("close");
		return -1;
	}
	return 0;
}

UDP服务器：

#include 
#define ERR_MSG(msg) do{fprintf(stderr,"__%d__\n",__LINE__);perror(msg);}while(0)
#define IP "192.168.115.105"
#define PORT 2222
int main(int argc, const char *argv[])
{
	//创建报式套接字
	int sfd;
	if((sfd = socket(AF_INET,SOCK_DGRAM,0)) < 0)
	{
		ERR_MSG("socket");
		return -1;
	}
	printf("socket success\n");
	//绑定IP地址和端口号，bind,必须绑定
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);
	if(bind(sfd,(struct sockaddr*)&sin,sizeof(sin)) < 0)
	{
		ERR_MSG("bind");
		return -1;
	}
	printf("bind success\n");
	char buf[128] = "";
	struct sockaddr_in cin;
	socklen_t sum = sizeof(cin);
	while(1)
	{
		bzero(buf,sizeof(buf));
		//接收
		if(recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr*)&cin,&sum) < 0)
		{
			ERR_MSG("recvfrom");
			break;
		}
		printf("recvfrom success sfd = %d : %s",sfd,buf);
		strcat(buf,">_<");
		//发送
		sendto(sfd,buf,sizeof(buf),0,(struct sockaddr*)&cin,sum);
	}
	//关闭文件
	if(close(sfd) < 0)
	{
		return -1;
	}
	return 0;
}

UDP客户端：

#include 
#define ERR_MSG(msg) do{fprintf(stderr,"__%d__\n",__LINE__);perror(msg);}while(0)
#define IP "192.168.115.105"
#define PORT 2222
int main(int argc, const char *argv[])
{
	//创建报式套接字
	int cfd;
	if((cfd = socket(AF_INET,SOCK_DGRAM,0)) < 0)
	{
		ERR_MSG("socket");
		return -1;
	}
	printf("socket success fd = %d\n",cfd);
	//绑定IP地址和端口号，bind,可以不绑定
	char buf[128] = "";
	struct sockaddr_in cin;
	cin.sin_family = AF_INET;
	cin.sin_port = htons(PORT);
	cin.sin_addr.s_addr = inet_addr(IP);
	socklen_t sum = sizeof(cin);
	while(1)
	{
		bzero(buf,sizeof(buf));
		//发送
		fgets(buf,sizeof(buf),stdin);
		buf[strlen(buf)-1]= '\0';
		sendto(cfd,buf,sizeof(buf),0,(struct sockaddr*)&cin,sum);
		bzero(buf,sizeof(buf));
		//接收
		if(recvfrom(cfd,buf,sizeof(buf),0,(struct sockaddr*)&cin,&sum) < 0)
		{
			ERR_MSG("recvfrom");
			break;
		}
		printf("recvfrom success sfd = %d : %s\n",cfd,buf);
	}
	//关闭文件
	if(close(cfd) < 0)
	{
		return -1;
	}
	return 0;
}