listener.c.txt

这是一款很通用的linux下的UDP通讯编程。适合于嵌入式linux平台不可靠网络通讯的开发等相关研究。

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

#define MYPORT 4950
#define MAXBUFLEN 100
int main(void){
  int sockfd;
  struct sockaddr_in my_addr;//my address information
  struct sockaddr_in their_addr;//connector's address information
  int addr_len,numbytes;
  char buf[MAXBUFLEN];
 /*setup socket*/
  if((sockfd=socket(AF_INET,SOCK_DGRAM,0))==-1){
      perror("socket");
      exit(1);
      }
  my_addr.sin_family=AF_INET;//host byte order
  my_addr.sin_port=htons(MYPORT);//short,network byte order
  my_addr.sin_addr.s_addr=INADDR_ANY;//automatically fill with my IP
  memset(&(my_addr.sin_zero),'\0',8);//zero the rest of the struct
 /*bind*/
  if(bind(sockfd,(struct sockaddr*)&my_addr,sizeof(struct sockaddr))    ==-1){
    perror("bind");
    exit(1);
    }
  /*receive the string from the client and print it*/
  while(1){
    addr_len=sizeof(struct sockaddr);
    if((numbytes=recvfrom(sockfd,buf,MAXBUFLEN-1,0,(struct          sockaddr*)&their_addr,&addr_len))==-1){
      perror("recvfrom");
      exit(1);
      }
  buf[numbytes]='\0';
     printf("%s says: %s",inet_ntoa(their_addr.sin_addr),buf);
    }
   close(scokfd);
   return 0;
}