服務端：server.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <errno.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#define PORT   12000
#define IP	  "192.168.48.130"

typedef struct SERVER_INFO
{
	int building;
	int uint;
	int room;
	unsigned int IPaddr;	
}INFO;



//初始化socket
void my_server(void)
{
	int socketfd = -1;
	int count = 0;
	struct sockaddr_in serveraddr;
	struct sockaddr_in clientaddr;
	
	char buf[100];
	
	
	//第一步，socket得到一個UDP的fd
	if((socketfd=socket(AF_INET,SOCK_DGRAM,0))<0)
	{
		perror("socket");
	}
	//設定IP地址
	int len=sizeof(clientaddr);
	bzero(&serveraddr,sizeof(serveraddr));
	serveraddr.sin_family=AF_INET;		//IP地址型別為IPv4
	serveraddr.sin_port=htons(PORT);	//埠號
	serveraddr.sin_addr.s_addr=inet_addr(IP);//繫結IP
	//第二步，bind伺服器的IP
	if((bind(socketfd,(const struct sockaddr *)&serveraddr,sizeof(serveraddr)))<0)
	{
		perror("bind");
	}
	else
	{
		printf("bind had success!\n");
	}
	
	//第三步，資訊的接收與傳送	
		//接收來自伺服器的資訊
		count=recvfrom(socketfd,buf,sizeof(buf),0,(struct sockaddr *)&clientaddr,&len);
		if(count<0)
			perror("recvfrom");
		else
		{	
		printf("server had recver %d byte\n",count);
		printf("server had recver %s byte\n",buf);
		}	
		memset(buf,0,sizeof(buf));
		//傳送資訊給客戶端
		//要傳送的結構體資訊
		int Buf[20];
		INFO fenji;
		Buf[0]=fenji.building=1010;
		Buf[1]=fenji.uint=1;
		Buf[2]=fenji.room=15;
		Buf[3]=fenji.IPaddr=1921681180;
		
		sendto(socketfd,Buf,sizeof(fenji),0,(const struct sockaddr *)&clientaddr,len);
		printf("had send struct fenji \n");
		
	close(socketfd);
	return;
}

int main(void)
{
	
	
	my_server();
	
	return 0;
}









































 

服務端：client.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <errno.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#define PORT   12000
#define IP	   "192.168.48.130"
char buf[]="hello server!";

void my_client(void)
{
	int socketfd = -1;
	int len=0;
	int count=0;
	struct sockaddr_in connectaddr;
	//第一步，socket得到一個UDP的fd
	if((socketfd=socket(AF_INET,SOCK_DGRAM,0))<0)
	{
		perror("socket");
	}
	//設定IP地址（IP為要連線的伺服器地址）
	bzero(&connectaddr,sizeof(connectaddr));
	connectaddr.sin_family=AF_INET;
	connectaddr.sin_port=htons(PORT);
	connectaddr.sin_addr.s_addr=inet_addr(IP);
	len=sizeof(connectaddr);
	/*		UDP不需要connect
	//第二步，連線connect
	if(connect(socketfd,(const struct sockaddr *)&connectaddr,len)<0)
	{
		perror("connect");
	}
	else
	{
		printf("connect is success!\n");
	}
	*/
	printf("buf=%s\n",buf);
	
	//客戶端向服務端傳送
	sendto(socketfd,buf,sizeof(buf),0,(const struct sockaddr *)&connectaddr,len);
	printf("buf=%s\n",buf);
	memset(buf,0,sizeof(buf));	
	
	//服務端接收客戶端的資訊
	int Buf[20];
	count=recvfrom(socketfd,Buf,sizeof(buf),0,(struct sockaddr *)&connectaddr,&len);

	printf("recive from server Buf[0]=%d\n",Buf[0]);
	printf("recive from server Buf[1]=%d\n",Buf[1]);
	printf("recive from server Buf[2]=%d\n",Buf[2]);
	printf("recive from server Buf[3]=%d\n",Buf[3]);
	close(socketfd);
	return;
}
int main(void)
{
	
	my_client();
	
	
	return 0;
}