/*
 * 'dev_rand.c' created: Thu Oct 17 14:15:19 2002
 *
 * Copyright 2002 by Lubomir Host <8host AT pauli.fmph.uniba.sk>
 *
 * License: GNU GPL (GNU Public License)
 *
 */

/* $Platon$ */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include "dev_rand.h"

RNG_device_t rng_dev_rand = {
	"rand()",
	-1, 0, 1E9,
	UINT_MAX, 11, /* 2^12 = 4096 random numbers per 1 cell */
	open_dev_rand,
	read_dev_rand,
	close_dev_rand
};


int open_dev_rand(void)
{
	int fd;
	int count;
	unsigned int seed;

	if ((fd = open("/dev/urandom", O_RDONLY)) == -1) {
		fprintf(stderr, "Initialization of rand() failed!\n");
		return RNG_FAIL;
	}
	count = read(fd, &seed, sizeof(unsigned int));
	if (count != sizeof(unsigned int)) {
		fprintf(stderr,
				"Read from /dev/urandom for initializaiton "
				"of rand() failed !\n");
		return RNG_FAIL;
	}
	close(fd);

	srand(seed);

	return RNG_OK;
}

Real_t read_dev_rand(void)
{
	return rand();
}

int close_dev_rand(void)
{
	return RNG_OK;
}


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