rand.c

一个类linux的dos下开发的操作系统.

unsigned long _seed;
/*****************************************************************************
*****************************************************************************/
long rand(void) /* stdlib.h */
{
	if(_seed == 0)
		_seed = 1;
	if((((_seed << 3) ^ _seed) & 0x80000000L) != 0)
		_seed = (_seed << 1) | 1;
	else
		_seed <<= 1;
	return _seed - 1;
}