UDP编程之一
单播模型
echoserver.c
1 #include <apue.h> 2 3 #define PORT 8080 4 #define LEN_BUF 255 5 6 void do_business(int sockfd); 7 8 int main(void) 9 { 10 //1.创建socket 11 int sockfd; 12 if((sockfd = socket(PF_INET,SOCK_DGRAM,0))<0) 13 ERR("socket failed"); 14 15 //2.绑定地址 16 struct sockaddr_in ipv4; 17 CLEAR(ipv4); 18 ipv4.sin_family = AF_INET; 19 ipv4.sin_port = htons(PORT); //NBO 20 //inet_pton(AF_INET,IP,&ipv4.sin_addr); 21 ipv4.sin_addr.s_addr = htonl(INADDR_ANY); //NBO 22 23 if(bind(sockfd,(struct sockaddr*)&ipv4,sizeof(ipv4))<0) 24 ERR("bind failed"); 25 26 //3.交互 27 do_business(sockfd); 28 29 //4.关闭 30 close(sockfd); 31 return 0; 32 } 33 34 void do_business(int sockfd) 35 { 36 struct sockaddr_in peer; 37 char buf[LEN_BUF]; 38 socklen_t len = sizeof(peer); 39 int n; 40 while(1) 41 { 42 if((n = recvfrom(sockfd,buf,sizeof(buf),0,(struct sockaddr*)&peer,&len))<0) 43 ERR("recv failed"); 44 if(sendto(sockfd,buf,n,0,(struct sockaddr*)&peer,sizeof(peer))<0) 45 ERR("send failed"); 46 } 47 }
echoclient.c
1 #include <apue.h> 2 3 #define PORT 8080 4 #define LEN_BUF 255 5 6 void do_business(const char *ipstr,unsigned short port,int sockfd); 7 8 int main(int argc,char **argv) 9 { 10 //0.解析命令行参数 11 if(argc!=3) 12 { 13 printf("Usage: %s <ip> <port>\n",argv[0]); 14 exit(0); 15 } 16 unsigned short port = strtol(argv[2],NULL,10); 17 18 //1.创建socket 19 int sockfd; 20 if((sockfd = socket(PF_INET,SOCK_DGRAM,0))<0) 21 ERR("socket failed"); 22 23 //3.交互 24 do_business(argv[1],port,sockfd); 25 26 //4.关闭 27 close(sockfd); 28 return 0; 29 } 30 31 void do_business(const char *ipstr,unsigned short port,int sockfd) 32 { 33 struct sockaddr_in peer; 34 CLEAR(peer); 35 peer.sin_family = AF_INET; 36 peer.sin_port = htons(port); 37 inet_pton(AF_INET,ipstr,&peer.sin_addr); 38 39 char buf[LEN_BUF],msg[LEN_BUF]; 40 int n; 41 while(1) 42 { 43 printf("shell# "); 44 fflush(stdout); 45 scanf("%s",buf); 46 if(sendto(sockfd,buf,strlen(buf),0,(struct sockaddr*)&peer,sizeof(peer))<0) 47 ERR("send failed"); 48 if((n = recvfrom(sockfd,msg,LEN_BUF,0,NULL,NULL))<0) 49 ERR("recv failed"); 50 msg[n] = 0; 51 printf("%s\n",msg); 52 } 53 }
