From: Damian Yerrick <MYNAMEISd_yerrick AT hotmail DOT comNO2CANNEDHAM>
Newsgroups: comp.os.msdos.programmer,comp.os.msdos.djgpp
Subject: Re: Uptime and entropy in DOS
Organization: Pin Eight Software  http://pineight.8m.com/
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References: <lra6ascbh1fu2d4738d44h09kpooc8ecta AT 4ax DOT com> <38A5583C DOT EDF375B4 AT is DOT elta DOT co DOT il>
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NNTP-Posting-Date: Sat, 12 Feb 2000 16:13:10 GMT
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Date: Sat, 12 Feb 2000 16:13:10 GMT
To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

On Sat, 12 Feb 2000 14:55:24 +0200, Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
wrote:

>Damian Yerrick wrote:
>> 
>> Is it possible to get the uptime of a DOS system?  I need more entropy
>> than the 32 bits I get from time(NULL) to initialize a pseudorandom
>> number generator.
>
>Did you try `uclock' or `gettiomeofday'?  It's in the FAQ (section 22.23).

uclock() won't work because it measures uptime of the current process,
which is *known* when the process starts, which is when I seed my PRNG
and start Allegro.  And because Allegro reprograms the timer, I can't
reseed from uclock() after the program starts.

gettimeofday() won't work because it in theory can be calculated from
time(NULL), which I'm already using, and adds no entropy.

-- 
Damian Yerrick  http://yerricde.tripod.com/
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