automatic TZ env-variable in localtime "problem" with W2000-germa n

[Markus K. E. Kommant]

Hello,
I have the following problem, or misunderstandig(!) of TZ variable in
cygwin1.dll.

Problem (and my current solution)

When I do not set TZ to a valid value, all times will be showed as GMT (or
UTC) time.
The automatic generated TZ variable in localtime.cc will generate a name
from GetTimeZoneInformation.

When I test this algorithm in a program, the name will be invalid (longer
than 3 characters).

At the moment I have problems to rebuild the cygwin1.dll (make will make a
lot of things but I do find a simple make cygwin1.dll...)

Is it a good, bad, very bad idea to test the length of the name against 3 to
generate a TZ variable compatible with tzparse?


localtime.cc (not tested, because I was not able to build cygwin1.dll)

	    GetTimeZoneInformation(&tz);
(...)
	    for (src = tz.StandardName; *src; src++)
	      if (is_upper(*src)) *dst++ = *src;

	    /* not 3 characters for timezone _tzname[0] ? 
               happens for example in Win2000/NT german version
               a) tz.StandardName is a WideChar String
               b) is very long "Westeropaische Normalzeit"
               generate a TZ variable relative to GMT-x
               (if strlen of _tzname is not equal 3 , tzparse will 
                not accept the TZ variable!)
               mkt */
            if (strlen(cp) != 3)            /* mkt */
            {                               /* mkt */
               strcpy(cp, "GMT");           /* mkt */
               dst = cp + 3;                /* mkt */
            }                               /* mkt */

(...) same for the daylight saving time with DST.

When I call this function as a separate routine win32_tzset (roughly written
in win32_tzset.c for my VC program and Cygwin-GNU ports) the TZ variable
will be understood and the correct times will be chown.

pdksh port with a call to win32_tzset to set TZ automatically from Windows
Control Panel:
pdksh $ echo $TZ
GMT-1DST-2,M3.5.0/2,M10.5.0/3
pdksh $ date
Mon Feb 11 17:35:54  2002
(yes this the current time)

bash-2.05a$ date
Mon Feb 11 16:36:25  2002
(no, this the UTC time)


 <<win32_tzset.c>>  <<localtime.cc>> 

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