rand.c File Reference

Rand for Elektra. More...

#include "kdbrand.h"
#include <kdbassert.h>
#include <time.h>

Include dependency graph for rand.c:

Functions
void	elektraRand (int32_t *seed)
	Non cryptographic pseudo random number generator. More...
int32_t	elektraRandGetInitSeed (void)
	Random initial seed generator. More...

Detailed Description

Rand for Elektra.

Copyright

BSD License (see LICENSE.md or https://www.libelektra.org)

Function Documentation

elektraRand()

void elektraRand

(

int32_t *

seed

)

Non cryptographic pseudo random number generator.

By Ray Gardner www8.cs.umu.se/~isak/snippets/rg_rand.c

based on "Random Number Generators: Good Ones Are Hard to Find", S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), and "Two Fast Implementations of the 'Minimal Standard' Random Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), p. 87-88

linear congruential generator f(z) = 16807 z mod (2 ** 31 - 1)

uses L. Schrage's method to avoid overflow problems

Make sure the initial seed is: 0 < seed < ELEKTRARANDMAX

Parameters

seed	a pointer to the seed

elektraRandGetInitSeed()

int32_t elektraRandGetInitSeed

(

void

)

Random initial seed generator.

Generates a random initial seed for the elektraRand (...) function. Two invocations in the same second return the same random initial seed, due to the usage of time (0).

Return values

random

initial seed