1/* Copyright (C) 1992-2022 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 Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the 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 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <stdlib.h>
19#include <stdio.h>
20
21int
22main (void)
23{
24 int i1, i2;
25 int j1, j2;
26
27 /* The C standard says that "If rand is called before any calls to
28 srand have been made, the same sequence shall be generated as
29 when srand is first called with a seed value of 1." */
30 i1 = rand();
31 i2 = rand();
32 srand (seed: 1);
33 j1 = rand();
34 j2 = rand();
35 if (i1 < 0 || i2 < 0 || j1 < 0 || j2 < 0) {
36 puts (s: "Test FAILED!");
37 }
38 if (j1 == i1 && j2 == i2)
39 {
40 puts (s: "Test succeeded.");
41 return 0;
42 }
43 else
44 {
45 if (j1 != i1)
46 printf (format: "%d != %d\n", j1, i1);
47 if (j2 != i2)
48 printf (format: "%d != %d\n", j2, i2);
49 puts (s: "Test FAILED!");
50 return 1;
51 }
52}
53

source code of glibc/stdlib/testrand.c