19991229: y2k bug detected in ldm5.0.8, pqact (palt.c) (fwd)

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Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================

---------- Forwarded message ----------
Date: Wed, 29 Dec 1999 15:36:55 -0700
From: Unidata Support <address@hidden>
To: address@hidden, address@hidden
Subject: 19991229: y2k bug detected in ldm5.0.8, pqact (palt.c)

>To: <address@hidden>
>From: "Albion Taylor" <address@hidden>
>Subject: y2k bug detected in ldm5.0.8, pqact (palt.c)
>Organization: .
>Keywords: 199912292224.PAA23381

We have been running ldm for quite some time, on an AIX 4.2.1 platform.  Our
pqact.conf file contains lines similar to

WMO     ^S[AP][AC-Z][A-Z].* .... ([0-3][0-9])
        FILE    data/obs/surface/hrly/(\1:yy)(\1:mm)\1.hrly

Some upstream products had time indicators of 01, indicating Jan 1 a little
early.  These were unexpectedly placed into a file named

-rw-r--r--   1 weather  staff        582 Dec 29 14:30 100101.hrly

as if the date information were expanded in a two-digit year of 10 (2010)
and a month of 01 and a day of 01.

An examination of the code in palt.c (around lines 641 to 645) suggests
that, if struct tm has a time_s->tm_year value which is year -1900 (i.e. 100
for 2000, 101 for 2001, etc), then (\n:yy) in pqact.conf files will expand
to the first two digits of a number greater than 100; i.e. we will have a
"year" value of 10 for the years 2000 to 2009, 11 for 2010 to 2019, etc.

I would suggest some attention be given to debugging this code.