基于UDP的简单收发消息代码

服务器端代码：

#include
#include
#include
#include
#include
#include
#include

#define N 64

typedef struct sockaddr SA;

int main(int argc, char *argv[])
{
 int sockfd;
 socklen_t addr_len;
 char buf[N];
 struct sockaddr_in myaddr, peeraddr;

 if (argc < 3)
 {
  printf("input format is : %s    \n", argv[0]);
  return -1;
 }

 if ((sockfd = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
 {
  perror("sock fail");
  return -1;
 }

 myaddr.sin_family = PF_INET;
 myaddr.sin_port = htons(atoi(argv[2]));
 myaddr.sin_addr.s_addr = inet_addr(argv[1]);

 if (bind(sockfd, (SA *)&myaddr, sizeof(myaddr)) == -1)
 {
  perror("bind fail");
  return -1;
 }

// while (1)
// {
  addr_len = sizeof(peeraddr);
  recvfrom(sockfd, buf, N, 0, (SA *)&peeraddr, &addr_len);
  printf("recv from client:%s\n", buf);
  strcat(buf, ": I am server");
  sendto(sockfd, buf, N, 0, (SA *)&peeraddr, addr_len);
// }

 return 0;
}

 

客户端代码如下：

#include
#include
#include
#include
#include
#include

#define N 64

typedef struct sockaddr SA;

int main(int argc, char *argv[])
{
 int sockfd;
 socklen_t addr_len;
 char buf[N];
 struct sockaddr_in peeraddr;

 if (argc < 3)
 {
  printf("input format is : %s    \n", argv[0]);
  return -1;
 }

 if ((sockfd = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
 {
  perror("sock fail");
  return -1;
 }

 peeraddr.sin_family = PF_INET;
 peeraddr.sin_port = htons(atoi(argv[2]));
 peeraddr.sin_addr.s_addr = inet_addr(argv[1]);

 strcpy(buf, "I am client");
 //while (1)
// {
  addr_len = sizeof(peeraddr);
  sendto(sockfd, buf, N, 0, (SA *)&peeraddr, addr_len);
  recvfrom(sockfd, buf, N, 0, (SA *)&peeraddr, &addr_len);
  printf("recv from server:%s\n", buf);
// }

 return 0;
}