Re: Equivalent of Linux timezone in FreeBSD

On 10/28/22 16:34, Stephen Montgomery-Smith wrote:
> On 10/28/22 00:55, Thomas Mueller wrote:
>> On Thu, 27 Oct 2022 13:32:55 -0600, Warner Losh wrote:
>>> On Thu, Oct 27, 2022 at 1:26 PM Stephen Montgomery-Smith <
>>> montgomerysmithstephen@gmail.com> wrote:
>>>
>>>> I am attempting to port code that uses an external variable called
>>>> timezone, which is defined in the Linux file time.h as the number of
>>>> seconds West of UTC for the current timezone.
>>>
> 
>>
>> The timezone variable is part of the POSIX XSI option (X/Open System
>> Interfaces). As mentioned in the original post it contains the number
>> of seconds West of UTC for the current timezone.
>>
>> Excerpt from  the standard text for tzset():
>>         #include <time.h>
>> [XSI]  extern int daylight;
>>         extern long timezone;
>> [CX]   extern char *tzname[2];
>>         void tzset(void);
>>         [...]
>> [XSI]  The tzset() function also shall set the external variable
>>         daylight to 0 if Daylight Savings Time conversions should 
>> never be
>>         applied for the timezone in use; otherwise, non-zero. The 
>> external
>>         variable timezone shall be set to the difference, in seconds, 
>> between
>>         Coordinated Universal Time (UTC) and local standard time.
>>
>> I suppose FreeBSD's tm_gmtoff field in "struct tm" is an equivalent.
>>
> 
> Excellent.  I replaced timezone with localtime(0)->tm_gmtoff.
> 
> Thank you very much.

Oops, I meant localtime(&zero)->tm_gmtoff, where zero is of type time_t.