stdlib/testrand.c

   1 /* Copyright (C) 1992, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21
  22 int
  23 main (void)
  24 {
  25   int i1, i2;
  26   int j1, j2;
  27
  28   /* The C standard says that "If rand is called before any calls to
  29      srand have been made, the same sequence shall be generated as
  30      when srand is first called with a seed value of 1." */
  31   i1 = rand();
  32   i2 = rand();
  33   srand (1);
  34   j1 = rand();
  35   j2 = rand();
  36   if (i1 < 0 || i2 < 0 || j1 < 0 || j2 < 0) {
  37       puts ("Test FAILED!");
  38   }
  39   if (j1 == i1 && j2 == i2)
  40     {
  41       puts ("Test succeeded.");
  42       return 0;
  43     }
  44   else
  45     {
  46       if (j1 != i1)
  47         printf ("%d != %d\n", j1, i1);
  48       if (j2 != i2)
  49         printf ("%d != %d\n", j2, i2);
  50       puts ("Test FAILED!");
  51       return 1;
  52     }
  53 }