#include <sys/types.h>
#include <sys/shm.h>
#include <strings.h>
#include <errno.h>

int
main (void)
{
  key_t mykey;
  int shmid;
  mykey = IPC_PRIVATE;

  printf ("creating private key \n");
  shmid = shmget (mykey, 65536, 0777);
  if (shmid != -1)
    printf ("shm id %x\n", shmid);
  else
    printf ("error %d, %s\n", errno, strerror (errno));


  printf ("creating shmget.c:1\n");
  mykey = ftok ("shmget.c", 1);

  shmid = shmget (mykey, 65536, 0777 | IPC_CREAT);
  if (shmid != -1)
    printf ("shm id %x\n", shmid);
  else
    {
      printf ("error %d, %s\n", errno, strerror (errno));
      return 1;
    }

  printf ("creating shmget.c:1 (should be same keyid)\n");
  mykey = ftok ("shmget.c", 1);

  shmid = shmget (mykey, 65536, 0777 | IPC_CREAT);
  if (shmid != -1)
    printf ("shm id %x\n", shmid);
  else
    {
      printf ("error %d, %s\n", errno, strerror (errno));
      return 1;
    }

  printf ("creating exclusive shmget.c:2\n");
  mykey = ftok ("shmget.c", 2);

  shmid = shmget (mykey, 65536, 0777 | IPC_CREAT | IPC_EXCL);
  if (shmid != -1)
    printf ("shm id %x\n", shmid);
  else
    {
      printf ("error %d, %s\n", errno, strerror (errno));
      return 1;
    }

  printf ("creating exclusive shmget.c:2 (should fail)\n");
  shmid = shmget (mykey, 65536, 0777 | IPC_CREAT | IPC_EXCL);
  if (shmid != -1 || (shmid == -1 && errno != EEXIST))
    {
      printf ("unexpected pass: shm id %x\n", shmid);
      return 1;
    }
  else
    printf ("error %d, %s\n", errno, strerror (errno));

  printf
    ("creating non-exclusive shmget.c:2 (should be the same as the prior id)\n");
  shmid = shmget (mykey, 65536, 0777 | IPC_CREAT);
  if (shmid != -1)
    printf ("shm id %x\n", shmid);
  else
    {
      printf ("error %d, %s\n", errno, strerror (errno));
      return 1;
    }

  return 0;
}