stdlib/testrand.c

   1 /* Copyright (C) 1992 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
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22
  23 int
  24 DEFUN_VOID(main)
  25 {
  26   int i1, i2;
  27   int j1, j2;
  28
  29   /* The C standard says that "If rand is called before any calls to
  30      srand have been made, the same sequence shall be generated as
  31      when srand is first called with a seed value of 1." */
  32   i1 = rand();
  33   i2 = rand();
  34   srand (1);
  35   j1 = rand();
  36   j2 = rand();
  37   if (j1 == i1 && j2 == i2)
  38     {
  39       puts ("Test succeeded.");
  40       return 0;
  41     }
  42   else
  43     {
  44       if (j1 != i1)
  45         printf ("%d != %d\n", j1, i1);
  46       if (j2 != i2)
  47         printf ("%d != %d\n", j2, i2);
  48       puts ("Test FAILED!");
  49       return 1;
  50     }
  51 }