rt-thread/examples/libc/rand.c

48 lines
1.0 KiB
C
Raw Normal View History

2013-01-08 21:05:02 +08:00
/*
* Copyright (c) 2006-2021, RT-Thread Development Team
2013-01-08 21:05:02 +08:00
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2010-11-17 Bernard first version
2013-01-08 21:05:02 +08:00
*/
2013-01-08 21:05:02 +08:00
#include <stdio.h>
#include <stdlib.h>
#include <finsh.h>
int libc_rand(void)
{
2021-03-07 08:34:04 +08:00
int i1, i2;
int j1, j2;
2013-01-08 21:05:02 +08:00
2021-03-07 08:34:04 +08:00
/* The C standard says that "If rand is called before any calls to
srand have been made, the same sequence shall be generated as
when srand is first called with a seed value of 1." */
i1 = rand();
i2 = rand();
srand(1);
j1 = rand();
j2 = rand();
if (i1 < 0 || i2 < 0 || j1 < 0 || j2 < 0)
{
puts("Test FAILED!");
}
if (j1 == i1 && j2 == i2)
{
puts("Test succeeded.");
return 0;
}
else
{
if (j1 != i1)
printf("%d != %d\n", j1, i1);
if (j2 != i2)
printf("%d != %d\n", j2, i2);
puts("Test FAILED!");
return 1;
}
2013-01-08 21:05:02 +08:00
}
FINSH_FUNCTION_EXPORT(libc_rand, rand test for libc);