rand.c

一个收集所有最基本功能的函数库；所有的函数都是尽量短小和简单 使用 doxygen 生成文档 所有代码以在 Linux 系统上可以编译并运行为准；每当在 lib 目录里增加了一个功能函数

/***************************************************************************
 *            rand.c
 *
 *  Mon May 21 18:00:48 2007
 *  Copyright  2007  kf701
 *  Email <kf701.ye AT gmail.com>
 ****************************************************************************/

/*
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
 
#include "kf701.h"
#include <time.h>

static bool rand_init_flag = false;

static void rand_init(void)
{
	srandom( time(NULL) + getpid() );
	rand_init_flag = true;
}

int32_t rand_int32_area(int32_t min, int32_t max)
{
	if( false == rand_init_flag )
		rand_init();

	int32_t i = max - min + 1;
	int32_t r = random();
	return ( r % i ) + min;
}

uint8_t rand_digit(void)
{
	return (uint8_t)rand_int32_area(0, 9);
}

uint8_t rand_alpha_lower(void)
{
	return (uint8_t)rand_int32_area(97, 122);
}

uint8_t rand_alpha_upper(void)
{
	return (uint8_t)rand_int32_area(65, 90);
}

uint8_t *rand_string(uint8_t *buf, uint32_t size)
{
	int i;
	for( i=0; i<size; i++ )
		buf[i] = (uint8_t)rand_int32_area(1, 255);
	buf[ size - 1 ] = 0;
	return buf;
}

uint8_t *rand_bytes(uint8_t *buf, uint32_t size)
{
	int i;
	for( i=0; i<size; i++ )
		buf[i] = (uint8_t)rand_int32_area(0, 255);
	return buf;
}

uint32_t rand_int32_from_str(const char *str)
{
	const char *p = str;
	uint32_t h = *p;
	if (h)
		for (p += 1; *p != '\0'; p++)
			h = (h << 5) - h + *p;
	return h;
}

char *rand_ip(char *buffer, uint32_t size)
{
	char p[16];
	sprintf( p, "%u.%u.%u.%u", rand_int32_area(0,255),rand_int32_area(0,255),
			rand_int32_area(0,255), rand_int32_area(0,255) );
	if( strlen(p) > size )
		return NULL;
	else
		strcpy(buffer, p);
	return buffer;
}