stdlib/tst-qsort.c

   1 /* Test case by Paul Eggert <eggert@twinsun.com> */
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4
   5 struct big { char c[4 * 1024]; };
   6
   7 struct big *array;
   8 struct big *array_end;
   9
  10 int
  11 compare (void const *a1, void const *b1)
  12 {
  13   struct big const *a = a1;
  14   struct big const *b = b1;
  15   if (! (array <= a && a < array_end
  16          && array <= b && b < array_end))
  17     {
  18       exit (EXIT_FAILURE);
  19     }
  20   return b->c[0] - a->c[0];
  21 }
  22
  23 int
  24 main (int argc, char **argv)
  25 {
  26   size_t i;
  27   size_t array_members = argv[1] ? atoi (argv[1]) : 50;
  28   array = (struct big *) malloc (array_members * sizeof *array);
  29   if (array == NULL)
  30     {
  31       puts ("no memory");
  32       exit (EXIT_FAILURE);
  33     }
  34
  35   array_end = array + array_members;
  36   for (i = 0; i < array_members; i++)
  37     array[i].c[0] = i % 128;
  38
  39   qsort (array, array_members, sizeof *array, compare);
  40
  41   return 0;
  42 }