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Re: Notes about timezones...
- To: Keet / Foxbird <Keetnet at wilmington dot net>, gnu-win32 at cygnus dot com
- Subject: Re: Notes about timezones...
- From: Earnie Boyd <earnie_boyd at yahoo dot com>
- Date: Tue, 3 Nov 1998 05:52:14 -0800 (PST)
- Reply-To: earnie_boyd at yahoo dot com
I believe that the SECSPERMIN macro is set to zero. It is not defined
in any header file and the fact that zero times something is always
zero.
---Keet / Foxbird <Keetnet@wilmington.net> wrote:
>
>
> I've got a small program that utilizes the 'timezone' variable, or the
> struct tm part of timezone. Appearently cygwin supports the 'timezone'
> variable, but it doesn't work correctly. Here's part of the program:
>
> time_t lt = time((long *) 0);
> extern long timezone;
> return timezone;
>
> That part will not compile because of the following error message:
>
> temp.c: In function `main':
> temp.c:10: `timezone' redeclared as different kind of symbol
>
D:\CygWin\b20\H-i586-cygwin32\lib\gcc-lib\i586-cygwin32\egcs-2.91.57\..\..\.
> .\..
> \i586-cygwin32\include\time.h:82: previous declaration of `timezone'
>
> So I open up time.h and quote the following from line 82:
>
> char *_EXFUN(timezone, (void));
>
> So I take that to mean that timezone should be set as 'extern char
> *timezone' or some derrivative.. I've tried just about everything,
and no
> go. I know I'm missing something here, but under unix 'extern long
> timezone' is the correct way to define it.
>
> Looking for an alternative, I decided to use _timezone, now that, is
> defined as 'extern long _timezone' or as 'extern time_t timezone'
(either
> work) and that compiles fine, if I change the above example to this:
>
> time_t lt = time((long *) 0);
> extern long _timezone;
> return _timezone;
>
> and all compiles and runs until I look at the result:
>
> _timezone = 0 ???
>
> That's certainly not true. So I snag a copy of the source (which took
> forever to get over a 28.8 connection) and look in the
winspu/times.cc file
> and spot the following section:
>
> --------------------------------------
> #undef _timezone
> #undef _daylight
> #undef _tzname
>
> time_t _timezone;
> int _daylight;
> char *_tzname[2] = { (char *) "GMT", (char *) " " };
>
> /* tzset: POSIX 8.3.2.1 */
> /* This function initializes timezone variables. */
> extern "C"
> void
> tzset ()
> {
> static NO_COPY char buf1[33], buf2[33];
>
> /* FIXME: This function should examine the TZ environment variable.
> Right now it just always sets information based on the system
> time zone. */
>
> TIME_ZONE_INFORMATION tz;
>
> GetTimeZoneInformation (&tz);
>
> _timezone = tz.Bias * SECSPERMIN;
> _daylight = tz.DaylightBias != 0;
> WideCharToMultiByte (CP_ACP, 0, tz.StandardName, -1, buf1, sizeof
buf1 - 1,
> NULL, NULL);
> buf1[sizeof buf1 - 1] = '\0';
> _tzname[0] = buf1;
> WideCharToMultiByte (CP_ACP, 0, tz.DaylightName, -1, buf2, sizeof
buf2 - 1,
> NULL, NULL);
> buf2[sizeof buf2 - 1] = '\0';
> _tzname[1] = buf2;
> }
> -----------------------------
>
> I looked at this and thought, hmmm.. it looks like it's definging
_timezone
> as the result of calling a WinAPI function, and multiplying by 60...
and
> the WinAPI function returns the # of minutes from UTC. Looks like it
should
> work to me, so where's the problem? To figure this out, I wrote a
small
> sample program that compares a bunch of variables.. but I need some
help
> interpreting this, and hopefully reach a fix for this ANNOYING
problem.
>
> --------- TEMP.C ----------------
>
> #include <time.h>
> #include <stdio.h>
> #include <string.h>
> #include <sys/time.h>
> #include <windows.h>
>
> int main () {
>
> extern long int _timezone;
> //extern time_t _timezone;
> extern long int *__imp__timezone;
> struct timezone tzone;
> TIME_ZONE_INFORMATION tz;
> time_t lt = time((long *) 0);
>
> GetTimeZoneInformation (&tz);
>
> fprintf(stderr, "Using GetTimeZoneInformation: %d\n", tz.Bias * 60);
> fprintf(stderr, "_timezone: %ld\n", _timezone);
> fprintf(stderr, "*__imp__timezone: %ld\n", *__imp__timezone);
> fprintf(stderr, "timezone.tz_minuteswest: %ld\n",
tzone.tz_minuteswest);
>
> }
>
> -----------------------
>
> The output is as follows:
>
> Using GetTimeZoneInformation: 18000
> _timezone: 0
> *__imp__timezone: 0
> timezone.tz_minuteswest: 39189696
>
> Considering that I am in the -0500 timezone, 18000 is right for the
number
> of seconds from UTC, but 0, 0, and that 39189696 numbers are WAY off.
> Looking back in review, I discover that calling the WinAPI function
> directly returns the right timezone information, but calling the
CygWin
> functions that set that information based on the WinAPI call, are all
> hosed. Anyone have any bright ideas?
>
> Notice, that in the above example, I've got the 'time_t _timezone'
part
> commented out. The result is the same either way, I just left it
that way
> when I last compiled it.
>
> Here are my system specs:
>
> P133 - 80MB Ram
> Windows 98
> Cygwin B20
>
> Results of cygcheck -s
>
> ----------------------
>
>
> Cygnus Win95/NT Configuration Diagnostics
> Current System Time: Sun Nov 01 22:21:36 1998
>
> Win9X Ver 4.10 build 67766222
>
> Path: /secondary/CYGWIN/B20/H-I586-CYGWIN32/BIN
> /secondary/CYGWIN/B20/TCL/BIN
> /secondary/BIN
> /usr/X11
> /usr/X11/BIN
> /usr/local/info
> /usr/local/include
> /usr/local/lib
> ./
> /primary/WINDOWS
> /primary/WINDOWS/COMMAND
> /primary/WINDOWS
> /primary/WINDOWS/COMMAND
> /primary/MOONGLOW/FTP/BIN/PERL/BIN
> /primary/BIN
> /primary/XSW
> //E/MOONGLOW/FTP/BIN/BIN
> /secondary/PKWARE
> /primary/F-PROT
> /usr/local/include/X11R6.3
> /usr/X11/X11R6.3/BIN
>
> SysDir: C:\WINDOWS\SYSTEM
> WinDir: C:\WINDOWS
>
> GCC_EXEC_PREFIX = `D:\CygWin\b20\H-i586-cygwin32\lib\gcc-lib\'
> TCL_LIBRARY = `d:\CygWin\b20\share\tcl8.0\'
> MAKE_MODE = `unix'
> HOME = `/usr'
>
> Use `-r' to scan registry
>
> a:\ fd N/A N/A
> c:\ hd FAT32 1031Mb 83% CP UN HDA
> d:\ hd FAT32 1031Mb 31% CP UN HDB
> e:\ hd FAT32 956Mb 72% CP UN HDC1
> f:\ fd FAT 95Mb 100% CP UN CYGWIN32
> g:\ cd N/A N/A
>
> d: / native text!=binary
> D:\bin /bin native text!=binary
> \\.\a: /dev/fd0 native text!=binary
> \\.\b: /dev/fd1 native text!=binary
> \\.\tape0: /dev/st0 native text!=binary
> \\.\tape1: /dev/st1 native text!=binary
> d:\usr\lib /lib native text!=binary
> d:\usr\man /man native text!=binary
> c: /primary native text!=binary
> d: /secondary native text!=binary
> d:\usr /tertiary native text!=binary
> d:\usr /usr/X11 native text!=binary
> d:\usr\include /usr/local/include native text!=binary
> d:\usr\lib /usr/local/info native text!=binary
> d:\usr\man /usr/local/lib native text!=binary
> d:\usr\info /usr/local/man native text!=binary
>
> Found: d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\bash.exe
> Found: d:\BIN\bash.exe
> Found: d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\cat.exe
> Not Found: cpp
> Found: d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\find.exe
> Found: c:\WINDOWS\COMMAND\find.exe
> Found: d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\gcc.exe
> Not Found: gdb
> Found: d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\ld.exe
> Found: d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\ls.exe
> Found: d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\make.exe
> Found: d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\sh.exe
> Found: d:\BIN\sh.exe
>
> 371k 1998/10/29 d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\cygtcl80.dll
> 5k 1998/10/29 d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\cygtclpip80.dll
> 10k 1998/10/29 d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\cygtclreg80.dll
> 600k 1998/10/29 d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\cygtk80.dll
> 429k 1998/10/29 d:\CYGWIN\B20\H-I586-CYGWIN32\BIN\cygwin1.dll
> 429k 1998/10/29 d:\usr\cygwin1.dll
> 429k 1998/10/29 d:\usr\cygwinb19.dll
> Use -h to see help about each section
>
> -------------------
>
> Any help anyone could provide me would be GREATLY appreciated.
>
> - Greg Neujahr
> keetnet@wilmington.net
>
> PS -- Please reply to my address, as well as the list.. it takes
forever to
> get traffic from the list for some reason.
>
>
> -
> For help on using this list (especially unsubscribing), send a
message to
> "gnu-win32-request@cygnus.com" with one line of text: "help".
>
==
- \\||//
-------------o0O0--Earnie--0O0o--------------
-- earnie_boyd@yahoo.com --
-- http://www.freeyellow.com/members5/gw32 --
----------------ooo0O--O0ooo-----------------
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