利用setsockopt实现超时检测

 

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

#define N 64

typedef struct sockaddr SA;

int main(int argc, char *argv[])
{
 int sockfd;
 char buf[N];
 struct sockaddr_in servaddr;
 struct timeval mytime;

 if (argc < 3)
 {
  printf("Usage : %s \n", argv[0]);
  exit(-1);
 }

 if ((sockfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
 {
  perror("fail to socket");
  exit(-1);
 }

 bzero(&servaddr, sizeof(servaddr));
 servaddr.sin_family = PF_INET;
 servaddr.sin_port = htons(atoi(argv[2]));
 servaddr.sin_addr.s_addr = inet_addr(argv[1]);

 mytime.tv_sec = 3;
 mytime.tv_usec = 0;

//设定超时时间

 if (setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &mytime, sizeof(mytime)) < 0)
 {
  perror("fail to setsockopt");
  exit(-1);
 }

 sendto(sockfd, buf, N, 0, (SA *)&servaddr, sizeof(servaddr));
 if (recvfrom(sockfd, buf, N, 0, NULL, NULL) < 0)
 {
  perror("fail to recvfrom");
 }
 

 return 0;
}