From:	Erik Max Francis <max AT alcyone DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Random implementation
Date:	Wed, 28 Jan 1998 01:15:39 -0800
Organization:	Alcyone Systems
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Jean-Luc Romano wrote:

> I could seed the function with time(NULL) like so:  srand(time(NULL));
> but (I think) that seeds the generator based on the system seconds,
> so one out of every 60 runs will produce the same random numbers.

ANSI C does not put any restrictions whatsoever on the encoding of the
the value returned by time.  In many systems, it is the number of
seconds since some reference date.

DJGPP is one of these systems, and as such, the value returned by time
will only repeat itself once every 2^32 seconds (srand takes an unsigned
int, which in DJGPP is the same size as a time_t).  2^32 s = 4.30 Gs =
136 y.  So it's hardly something to worry about.

Calling srand(time(0)) is the conventional way to seed the random number
generator.

-- 
         Erik Max Francis, &tSftDotIotE / mailto:max AT alcyone DOT com
                       Alcyone Systems / http://www.alcyone.com/max/
  San Jose, California, United States / icbm://+37.20.07/-121.53.38
                                     \
                       "Life may be / the product of imperfections."
                                   / (Marclo Gleiser)

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