From:	"John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: real random numbers
Date:	Thu, 26 Mar 1998 18:24:00 -0500
Organization:	Two pounds of chaos and a pinch of salt.
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Message-ID:	<351AE390.2516@cs.com>
References:	<351634A2 DOT 5ACD AT hol DOT fr> <35169C99 DOT 3B53 AT pobox DOT oleane DOT com> <6fe13v$55q AT tuegate DOT tue DOT nl>
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To:	djgpp AT delorie DOT com
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hat AT se-46 DOT wpa DOT wtb DOT tue DOT nl wrote:
> 
> As some people already have pointed out, this only works when your
> program runs at least for a single second.
> Does somebody know how to take care of getting a different value each
> time you run a program, no matter how often in a single second you start
> it ?

The header <sys/time.h> declares a function called gettimeofday()
(q.v.).  The struct returned by this function contains the current GTM
time accurate to the millisecond.  Unless your program runs faster than
once every millisecond (very difficult to do on a DOS box), this value
should be adequate to use as a seed.

If you want to get really esoteric, when your program exits you could
have it produce a random number, write it to disk, and then read it in
the next time to use as the seed.

-- 
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|      John M. Aldrich       |"Men rarely (if ever) manage to dream |
|       aka Fighteer I       |up a god superior to themselves. Most |
|   mailto:fighteer AT cs DOT com   |gods have the manners and morals of a |
| http://www.cs.com/fighteer |spoiled child."    - Lazarus Long     |
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