#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

void *do_sbrk (intptr_t incr)
{
  void *rv = sbrk (incr);
  printf ("sbrk (%llx) -> %p\n", (long long) incr, rv);
  if (rv == (void *) -1) {
    printf ("  errno = %d (%s)\n", errno, strerror (errno));
  }
  return rv;
}

int main (void)
{
  setvbuf (stdout, NULL, _IOLBF, 0);
  printf ("starting\n");
  void *rv0 = do_sbrk (0);
  void *rv1 = do_sbrk (1 << 30);
  void *rv2 = do_sbrk (0);
  printf ("%p, %p, %p\n", rv0, rv1, rv2);
  if (rv1 == rv2) {
    printf ("rv1 == rv2, lose!\n");
    exit (EXIT_FAILURE);
  }
  printf ("done\n");
}