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

int main()
{
 int fd = socket(AF_INET, SOCK_STREAM, 0);
 int a = 1;
 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &a, sizeof(a));
 sockaddr_in addr;

 addr.sin_family = AF_INET;
 addr.sin_port = htons(8888);
 inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr.s_addr);

 int err = bind(fd, (sockaddr *)&addr, sizeof(addr));
 if (err < 0)
 {
 printf("bind err%d\n", err);
 return 0;
 }
 //kaishi select
 int max = fd;
 fd_set readfds;
 fd_set tempfds;
 FD_ZERO(&readfds);
 FD_SET(fd, &readfds);
 listen(fd, 10);
 while (1)
 {
 tempfds = readfds;
 int n = select(max + 1, &tempfds, nullptr, nullptr, nullptr);
 if (n < 0)
 {
 if (errno == ECONNABORTED || errno == EINTR)
 {
 continue;
 }
 break;
 } //you link
 if (FD_ISSET(fd, &tempfds))
 {
 int acfd = accept(fd, nullptr, nullptr);
 printf("%d accepy yes\n", acfd);
 FD_SET(acfd, &readfds); // linsten->>>read fd
 if (max < acfd)
 {

 max = acfd;
 }
 if (--n == 0) //only one fd change
 {
 continue;
 }
 }

 for (int i = fd + 1; i <= max; i++) //have string
 {
 printf("%d for yes\n", i);
 if (FD_ISSET(i, &tempfds))
 {
 char buff[64];
 //while (1)
 //{
 int nread = read(i, buff, 64);
 write(i, "yes", sizeof("yes"));
 if (nread <= 0)
 {
 FD_CLR(i, &readfds);
 close(i);
 break;
 //pop unuse fd and close
 }
 printf("%s\n", buff);
 if (--n == 0) //only one fd change
 {
 continue;
 }
 //}
 }
 }
 }
}