UDP_QQ

#include
#include
#include
#include
#include
#include
#include
//./a.out 8000

void *my_send_fun(void *arg)
{
	int sockfd =*(int *)arg;
	
	struct sockaddr_in dst_addr;
	bzero(&dst_addr,sizeof(dst_addr));
	dst_addr.sin_family=AF_INET;
	while(1)
	{

		char buf[128]="";
		fgets(buf,sizeof(buf),stdin);
		buf[strlen(buf)-1]=0;
		
		if(strncmp(buf,"sayto",5)==0)
		{
			unsigned short port=0;
			char ip[16]="";
			
			sscanf(buf,"sayto %s %hd",ip,&port);
			dst_addr.sin_port=htons(port);
			inet_pton(AF_INET,ip,&dst_addr.sin_addr.s_addr);
			continue;
		}
		
		else
		{
			sendto(sockfd,buf,strlen(buf),0,\
			(struct sockaddr *)&dst_addr,sizeof(dst_addr));
		}
	}
	return NULL;
}


int main(int argc,char *argv[])
{
	if(argc !=2)
	{
		printf("please input port");
		return 0;
	}
	int sockfd =socket(AF_INET,SOCK_DGRAM,0);
	
	//bind
	struct sockaddr_in my_addr;
	bzero(&my_addr,sizeof(my_addr));
	my_addr.sin_family=AF_INET;
	my_addr.sin_port=htons(atoi(argv[1]));//主函数传参
	//my_addr.sin_addr.s_addr=htonl(INADDR_ANY);
	bind(sockfd,(struct sockaddr *)&my_addr,sizeof(my_addr));
	
	//创建一个发送线程
	pthread_t tid;
	pthread_create(&tid,NULL,my_send_fun,(void *)&sockfd);
	pthread_detach(tid);
	
	//接收线程
	while(1)
	{
		char buf[128]="";
		struct sockaddr_in from;
		socklen_t len = sizeof(from);
		
		recvfrom(sockfd,buf,sizeof(buf),0,(struct sockaddr *)&from,&len);
		unsigned short port =ntohs(from.sin_port);
		char ip[16]="";
		inet_ntop(AF_INET,&from.sin_addr.s_addr,ip,16);
		printf("来自%s:%hu %s\n",ip,port,buf);
	}
	return 0;
}