#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <netinet/in.h>

int main(int argc, char* argv[])
{
  int status;
  int server_sock;

  if (argc==2) {
    if (strcmp(argv[1], "child")==0) {
      printf("child started.\n");
      for(int i = 0; i < getdtablesize(); i++) {
	if ((status = fcntl(i, F_GETFD))<0) continue;
	printf("child fd %d open\n", i);
      }
      sleep(10);
      printf("child end.\n");
      exit(0);
    }
  }

  /* Server setup */
  sockaddr_in server_sin;
  server_sin.sin_family = AF_INET;
  server_sin.sin_addr.s_addr = htonl(INADDR_ANY);
  server_sin.sin_port = htons(short(8888));
  memset(server_sin.sin_zero, 0, sizeof(server_sin.sin_zero));

  /* Server */
  server_sock = socket(AF_INET, SOCK_STREAM, 0);
  
  if ((status = fcntl(server_sock, F_GETFD))<0) {
    printf("fcntl get:%s\n", strerror(errno));
    exit(0);
  }
  printf("fcntl get %X\n", status);
  status |= FD_CLOEXEC;
  printf("fcntl set %X\n", status);
  if (fcntl(server_sock, F_SETFD, status)==-1) {
    printf("fcntl set close-exec:%s\n", strerror(errno));
    exit(0);
  }
   
  status = bind(server_sock, (struct sockaddr *) &server_sin,
		sizeof(struct sockaddr));
  
  if (status != -1) {
    status = listen(server_sock, SOMAXCONN);
    printf("server port listening.\n");
  }
  
  pid_t pid;
  if ((pid = fork())==0) {
  //  if (0) {

    printf("spawning child...\n");
    status = execlp("test1","test1","child", NULL);
    perror("test1: ");
    exit(0);

  } else {

    close(server_sock);
    printf("server socket closed.\n");
    /* now try to connect to inherited socket */
    int sock;
    sock = socket(AF_INET, SOCK_STREAM, 0);

    sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
    sin.sin_port = htons(short(8888));

    if (connect(sock, (sockaddr*)&sin, sizeof(sin)) == 0) {
      printf("server process connected\n");
    } else {
      perror("connect: ");
    }
    
    exit(0);
  }
}