Date: Wed, 14 Apr 93 17:44:04 EDT
From: ronis AT onsager DOT chem DOT mcgill DOT ca (David Ronis)
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: TZ environment variable and time functions

Hi,

I've written a program that uses several  of the time functions.  My
problem is that I need to compile things both with djgpp as well as a
real mode C compiler (MSC).  As far as I can tell,  djgpp is smart
enough to figure out when daylight savings time goes into effect with
the simple TZ=EST5 environment variable setting; MSC is not, and
requires something like TZ=EST5DST, which has strange effects under
djgpp.

Now my question.  While I could temporarily change the environment
variable within a batch file, I though that it would be simpler to
simply change the environment variable to the shorter one (EST5) using
setenv() or putenv() in the djgpp program.  To be sure, when I do this
subsequent calls to getenv() return the sortened variable.  However,
tzset() and the time routines (which are only called afterwards) seem
to ignore the new setting.  Is this because, djgpp pops back to real
mode, with a different copy of the environment table,  when the time
calls are made?  If so, any suggestions as to how to fix this bug?


Thanks in advance.


David Ronis