FC: More on Unix has turned one billion! (seconds, that is)

[Declan McCullagh <declan () well com>]

********

Date: Sun, 9 Sep 2001 12:14:28 +0100
From: David Cantrell <david () cantrell org uk>
To: Declan McCullagh <declan () well com>
Subject: Re: FC: Unix has turned one billion! (seconds, that is)

You may be surprised to learn that contrary to popular belief, there
*is* a chance that some things will have gone wrong when we went
from 999,999,999 to 1,000,000,000.

If you sort those numbers in ASCII order as opposed to numeric order,
then 1,000,000,000 comes first.  Programs written in languages which
don't rigourously enforce the difference between numbers and strings,
such as many scripting languages and programming languages like perl
may therefore sort dates wrongly if the programmer is insufficiently
careful.  This will lead to all sorts of fun and games if - for
instance - such a script is being used to delete the ten oldest files
in a directory, as it'll suddenly start deleting the ten newest.  It's
unlikely, however, that such scripts are doing anything of earth-
shattering importance.

Most of these errors will, I imagine, do nothing more than embarrass
people when their websites start sorting things incorrectly.  But
there have been a few commercial products found to have this bug.

One of the tools making up an old version of the Veritas backup
software, for example.  In that case, it was written in Java (a
strongly typed language so the programmer must have been monumentally
stupid to compare numbers ACSII-betically) and was only a tool for
looking at backup sets and wouldn't affect the integrity of backups.
No doubt you would expect that any organisation sensible enough to
be using backup software would also be sensible enough to keep it
patched up-to-date.  But I doubt it.  There *will* be a few failures
due to this bug in commercial software, but considering how rare the
bug is in the first place and that manufacturers have mainly caught
it and patched it, then the risk is very very minor indeed.

--
David Cantrell | david () cantrell org uk | http://www.cantrell.org.uk/david

Cutting the space budget really restores my faith in humanity.  It
eliminates dreams, goals, and ideals and lets us get straight to the
business of hate, debauchery, and self-annihilation.
                -- Johnny Hart




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