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Groups > comp.lang.forth > #7386

Re: most portable way to compare file times

From anton@mips.complang.tuwien.ac.at (Anton Ertl)
Subject Re: most portable way to compare file times
Newsgroups comp.lang.forth
References (2 earlier) <e049fd77-3b60-4f0a-b7ed-366df3b797b1@l24g2000yqm.googlegroups.com> <53e468dd-ed4e-4b1b-9e1a-738a065df9a5@p16g2000yqd.googlegroups.com> <ja6ak2$iqq$1@online.de> <p4idnWEyga4rVFvTnZ2dnUVZ_u6dnZ2d@supernews.com> <95241ce5-96f2-4b7b-92b2-2ea54cbef8ea@p1g2000yqh.googlegroups.com>
Organization Institut fuer Computersprachen, Technische Universitaet Wien
Date 2011-11-21 10:22 +0000
Message-ID <2011Nov21.112244@mips.complang.tuwien.ac.at> (permalink)

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Alex McDonald <blog@rivadpm.com> writes:
>On Nov 18, 9:10=A0pm, Andrew Haley <andre...@littlepinkcloud.invalid>
>wrote:
>> Bernd Paysan <bernd.pay...@gmx.de> wrote:
>> > For a file time stamp, seconds are probably good enough

Not really, but most file systems don't provide anything better.

>There are applications where seconds are definitely not good enough.
>
>And Unix insists on the daftness of two 32bit fields; one accurate to
>the second that expires in 2038, and the other in microseconds encoded
>as a 32bit number. Insanity.

Unix has several funny time specifications, but they are not relevant
for Forth.

I suggest to use doubles as the basic time format for Forth.  Do we
really need to standardize the units used? (If we just need to know
which was earlier, the units are irrelevant).  Or do we prefer to
standardize a conversion word from the unspecified tick unit to real
units?

If we want to standardize units, microseconds seem to be a good match
for systems with 32-bit cells: fine-grained enough for most purposes
in the foreseeable future (and given that the CPU clock rates have
mostly stopped increasing, that's probably going to be good enough for
a while), with a range of more than 200,000 years on either side of
the Epoch, which should also be good enough for most purposes.

Alternatively, Nanoseconds, which gives us only ~280 years or so on
either side of the Epoch, and those people who need more should use
64-bit systems.

16-bit systems won't be very happy with either unit, but it ISTM that
16-bit systems prefer compactness to standardness anyway.

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
     New standard: http://www.forth200x.org/forth200x.html
   EuroForth 2011: http://www.euroforth.org/ef11/

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Thread

most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-18 00:43 -0800
  Re: most portable way to compare file times Alex McDonald <blog@rivadpm.com> - 2011-11-18 02:33 -0800
    Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-18 05:26 -0800
      Re: most portable way to compare file times Alex McDonald <blog@rivadpm.com> - 2011-11-18 09:14 -0800
        Re: most portable way to compare file times Bernd Paysan <bernd.paysan@gmx.de> - 2011-11-18 20:10 +0100
          Re: most portable way to compare file times Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-11-18 15:10 -0600
            Re: most portable way to compare file times Alex McDonald <blog@rivadpm.com> - 2011-11-18 13:32 -0800
              Re: most portable way to compare file times anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-11-21 10:22 +0000
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-21 08:51 -0800
            Re: most portable way to compare file times Bernd Paysan <bernd.paysan@gmx.de> - 2011-11-19 00:57 +0100
        Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-18 14:45 -0800
  Re: most portable way to compare file times "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2011-11-18 05:44 -0500
    Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-18 05:31 -0800
      Re: most portable way to compare file times anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-11-18 16:22 +0000
        Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-19 13:59 -0800
          Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-20 02:06 -0800
            Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-20 02:44 -0800
              Re: most portable way to compare file times Bernd Paysan <bernd.paysan@gmx.de> - 2011-11-20 14:58 +0100
                Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-20 06:48 -0800
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-20 08:05 -0800
                Re: most portable way to compare file times Coos Haak <chforth@hccnet.nl> - 2011-11-20 20:53 +0100
                Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-20 12:21 -0800
                Re: most portable way to compare file times Bernd Paysan <bernd.paysan@gmx.de> - 2011-11-21 21:03 +0100
                Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-21 17:32 -0800
                Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-21 17:45 -0800
                Re: most portable way to compare file times Bernd Paysan <bernd.paysan@gmx.de> - 2011-11-24 15:48 +0100
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-24 09:34 -0800
                Re: most portable way to compare file times Alex McDonald <blog@rivadpm.com> - 2011-11-24 11:58 -0800
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-24 17:25 -0800
                Re: most portable way to compare file times "Elizabeth D. Rather" <erather@forth.com> - 2011-11-24 20:56 -1000
                Re: most portable way to compare file times Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-11-25 04:15 -0600
                Re: most portable way to compare file times Alex McDonald <blog@rivadpm.com> - 2011-11-25 04:17 -0800
                Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-25 05:47 -0800
                Re: most portable way to compare file times Alex McDonald <blog@rivadpm.com> - 2011-11-25 08:58 -0800
                Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-25 11:43 -0800
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-25 11:12 -0800
                Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-25 05:39 -0800
                Re: most portable way to compare file times anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2011-11-27 14:34 +0000
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-27 08:46 -0800
                Re: most portable way to compare file times Alex McDonald <blog@rivadpm.com> - 2011-11-25 04:32 -0800
                Re: most portable way to compare file times Alex McDonald <blog@rivadpm.com> - 2011-11-25 04:51 -0800
                Re: most portable way to compare file times Bernd Paysan <bernd.paysan@gmx.de> - 2011-11-25 16:46 +0100
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-25 08:33 -0800
                Re: most portable way to compare file times Bernd Paysan <bernd.paysan@gmx.de> - 2011-11-26 01:11 +0100
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-26 12:18 -0800
                Re: most portable way to compare file times Bernd Paysan <bernd.paysan@gmx.de> - 2011-11-26 21:44 +0100
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-26 13:18 -0800
                Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-20 12:45 -0800
            Re: most portable way to compare file times Krishna Myneni <krishna.myneni@ccreweb.org> - 2011-11-20 07:49 -0800
        Re: most portable way to compare file times mhx@iae.nl (Marcel Hendrix) - 2011-11-20 09:45 +0200
      Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-18 10:42 -0800
  Re: most portable way to compare file times BruceMcF <agila61@netscape.net> - 2011-11-20 13:05 -0800

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