UDP网络程序设计

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <sys/socket.h>
 4 #include <netinet/in.h>
 5 
 6 #define PORT 8888
 7 #define MSG_SIZE 128
 8 
 9 int main()
10 {
11     int sockfd;
12     struct sockaddr_in server_addr;
13     struct sockaddr_in client_addr;
14     char buffer[MSG_SIZE];
15     int addrlen;
16     int n;
17 
18     //创建套接字
19     sockfd = socket(AF_INET,SOCK_DGRAM,0);
20 
21     //绑定地址
22     bzero(&server_addr,sizeof(struct sockaddr_in));
23     server_addr.sin_family = AF_INET;
24     server_addr.sin_port = htons(PORT);
25     server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
26 
27     bind(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr));
28 
29     //接收数据
30     while(1)
31     {
32         addrlen = sizeof(struct sockaddr);
33         bzero(buffer,sizeof(buffer));
34         n = recvfrom(sockfd,buffer,MSGZ-SIZE,0,(struct sockaddr *)(&client_addr),&addrlen);
35         buffer[n]=0;//加上结束符
36         printf("Server received: %s\n",buffer);
37     }
38 
39     //结束连接
40     close(sockfd);
41     
42     return 0;
43 }

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <sys/socket.h>
 4 #include <netinet/in.h>
 5 
 6 #define BUF_SIZE 128
 7 #define PORT 8888
 8 
 9 int main(int argc, char **argv)
10 {
11     int sockfd;
12     char buffer[BUF_SIZE];
13     struct sockaddr_in server_addr;
14 
15     if(argc != 2)
16     {
17         printf("Usage: %s server_ip\n",argv[0]);
18         exit(1);
19     }
20 
21     //创建套接字
22     sockfd = socket(AF_INET,SOCK_DGRAM,0);
23 
24     //初始化服务器地址
25     bzero(&server_addr,sizeof(struct sockaddr_in));
26     server_addr.sin_family = AF_INET;
27     server_addr.sin_port = htons(PORT);
28     inet_aton(argv[1],&server_addr.sin_addr)
29     
30     //发送数据
31     while(1)
32     {
33         printf("Please input char:\n");
34         fgets(buffer,BUF_SIZE,stdin);
35         sendto(sockfd,buffer,strlen(buffer),0,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr));
36         bzero(buffer,BUF_SIZE);
37     }
38 
39     close(sockfd);
40     
41     return 0;
42 }