Re: cygcheck's understanding of TZ

[Christopher Faylor <cgf-use-the-mailinglist-please@cygwin.com>]

On Thu, Jun 09, 2011 at 12:39:04PM -0500, Edward McGuire wrote:
>On Thu, Jun 9, 2011 at 02:46, EXCOFFIER Denis
><denis.excoffier@c-s.fr> wrote:
>> It seems that /usr/bin/cygcheck does not interpret TZ the same way
>> as /usr/bin/date does, in the case TZ is set to a file name
>> [snip]
>> jupiter% (setenv TZ /usr/share/zoneinfo/Europe/Monaco; date; cygdate)
>
>There are two standard syntaxes for TZ. One begins with a timezone
>name, the other begins with a colon (:). If you supply a colon, then
>the rest of the string is interpreted in an operating system
>specific manner. GNU interprets it as a pathname. And Cygwin uses
>GNU's time library.

If by "Cygwin" you mean the dll, then it doesn't use GNU's time library
but it does try to match the same behavior.

>Na??vely, I thought you might just lack a colon on the front of the
>pathname. I confirmed time(1) honors the pathname syntax. But
>cygcheck(1) mysteriously interprets all pathnames as GMT + 1 hour:
>
>$ TZ=:/usr/share/zoneinfo/US/Central cygcheck -s | head -3 | tail -1
>Current System Time: Thu Jun 09 18:23:42 2011

cygcheck is a non-Cygwin application.  It is not surprising that it would
not interpret TZ in a way that is consistent with linux.  It really
makes no sense at all to use cygcheck as some sort of method to report
the system time.  Use 'date(1)'.

>$ TZ=:/usr/share/zoneinfo/Europe/Monaco cygcheck -s | head -3 | tail -1
>Current System Time: Thu Jun 09 18:23:49 2011
>$ TZ=:/usr/share/zoneinfo/GMT cygcheck -s | head -3 | tail -1
>Current System Time: Thu Jun 09 18:23:56 2011
>$ TZ=:/usr/share/zoneinfo/Asia/Calcutta cygcheck -s | head -3 | tail -1
>Current System Time: Thu Jun 09 18:23:59 2011
>
>It gets local time right:
>
>$ cygcheck -s | head -3 | tail -1
>Current System Time: Thu Jun 09 12:25:04 2011
>
>And it gets GMT right:
>
>$ TZ=GMT cygcheck -s | head -3 | tail -1
>Current System Time: Thu Jun 09 17:31:32 2011
>
>So cygcheck(1) is honoring TZ, but it trips over a pathname in a
>way that date(1) does not.

And date(1) is what you should be using.

cgf

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