Linux一对一通信(UDP)

客户端：

#include<stdio.h>  
#include<unistd.h>  
#include<stdlib.h>  
#include<sys/socket.h>  
#include <sys/socket.h>
#include<string.h>  
#include <arpa/inet.h>

#define MAX_BUF_SIZE 1024  
#define PORT 8888  

int main()   
{  
   int sockfd, addrlen, n;  
   char buffer[MAX_BUF_SIZE];  
   struct sockaddr_in addr;  
   sockfd = socket(AF_INET, SOCK_DGRAM, 0);  
   if (sockfd < 0)  
   {  
      fprintf(stderr, "socket falied
");  
      exit(EXIT_FAILURE);  
   }  
   addrlen = sizeof(struct sockaddr_in);  
   bzero(&addr, addrlen);  
   addr.sin_family = AF_INET;  
   addr.sin_port = htons(PORT);  
   addr.sin_addr.s_addr = htonl(INADDR_ANY);  

   puts("socket success");  
   while(1)  
   {  
       bzero(buffer, MAX_BUF_SIZE);  
       fgets(buffer, MAX_BUF_SIZE, stdin);  
       sendto(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)(&addr), addrlen);  
       printf("client send msg is %s
", buffer);  
       n = recvfrom(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)(&addr), &addrlen);  
       fprintf(stdout, "clinet Receive message from server is %s
", buffer);  
   }  
   close(sockfd);  
   exit(0);  
   return 0;  
}  

服务端：

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

#define PORT 8888  
#define MAX_MSG_SIZE 1024

int main()
{
       int sockfd, addrlen, n;  
       struct sockaddr_in addr;  
       char msg[MAX_MSG_SIZE];  
       sockfd = socket(AF_INET, SOCK_DGRAM, 0);  //数据报
       if (sockfd < 0)  
       {  
          fprintf(stderr, "socket failed
");  
          exit(EXIT_FAILURE);  
       }  
       addrlen = sizeof(struct sockaddr_in);  
       bzero(&addr, addrlen);  //清空addr
       addr.sin_family = AF_INET;  
       addr.sin_addr.s_addr = htonl(INADDR_ANY);  
       addr.sin_port = htons(PORT);  
       if (bind(sockfd, (struct sockaddr*)(&addr), addrlen) < 0)  
       {  
          fprintf(stderr, "bind fail
");  
          exit(EXIT_FAILURE);  
       }  
       puts("bind success");  
       while (1)  
       {  
          bzero(msg, MAX_MSG_SIZE);  //清空数组
          n = recvfrom(sockfd, msg, sizeof(msg), 0, (struct sockaddr *)(&addr), &addrlen);  
          fprintf(stdout, "Recevie message from client is %s
", msg);  
          fgets(msg, MAX_MSG_SIZE,stdin);  
          printf("Server endpoint input message %s
", msg);  
          sendto(sockfd, msg, n, 0,(struct sockaddr *)(&addr), addrlen);  
       }  
       close(sockfd);  
       exit(EXIT_SUCCESS);  
}