Re: Problem with DateTime::Format::DateManip v0.01
On Thu, 4 Sep 2003, Dave Rolsky wrote:
> On Thu, 4 Sep 2003, David Wheeler wrote:
>
> > > It's probably that simple. Simply setting the TZ env var probably
> > > won't
> > > do much. An app has to call POSIX::tzset() for that take effect.
> >
> > I find that for most date and time handling I do, just setting $ENV{TZ}
> > does the trick -- except perhaps on Debian. Are you saying that if I
> > want the setting of TZ to portably affect, e.g., localtime, that I need
> > to always POSIX::tzset() after I do it? Seems a waste to load all of
> > POSIX.pm just for that...
>
> I'm pretty sure you have to do that. For example, if you simply set
> $ENV{TZ} then localtime() doesn't change in this script:
You have to call tzset() on some platforms when you change TZ at runtime.
# this prints Tokyo time
export TZ="Asia/Tokyo"
perl -le 'print scalar localtime'
# and this doesn't on Solaris but does on Gentoo
perl -le '$ENV{TZ} = "Asia/Tokyo"; print scalar localtime'
# and this always does
perl -MPOSIX -le '$ENV{TZ} = "Asia/Tokyo"; POSIX::tzset; print scalar localtime'
So there is a difference, on some platform(s), between inheriting the value of TZ from
the environment and setting it at runtime. Using tzset() is the 'portable' thing to
do.
Didn't I answer an almost identical question from David a few months ago?
-J
--
Re: Problem with DateTime::Format::DateManip v0.01
On Thursday, September 4, 2003, at 09:37 PM, Dave Rolsky wrote:
I'm pretty sure you have to do that. For example, if you simply set
$ENV{TZ} then localtime() doesn't change in this script:
perl -le 'print scalar localtime; $ENV{TZ} = "Asia/Tokyo"; print
scalar localtime'
But in this one it does
perl -MPOSIX -le 'print scalar localtime; $ENV{TZ} = "Asia/Tokyo";
POSIX::tzset(); print scalar localtime'
Damn, okay, thanks.
Can you do another test for me (since I don't have a platform that
needs tzset)? Can you tell me how it affects use of local? Here's a
test script:
#!/usr/bin/perl -w
use strict;
use POSIX qw(tzset);
print scalar localtime, $/;
{
local $ENV{TZ} = "Asia/Tokyo";
tzset;
print scalar localtime, $/;
}
print scalar localtime, $/;
The question is, what does the third print statement print? Do I need
to call tzset again after the block?
TIA,
David
--
David Wheeler AIM: dwTheory
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Re: Problem with DateTime::Format::DateManip v0.01
On Friday, September 5, 2003, at 12:50 AM, Joshua Hoblitt wrote: So there is a difference, on some platform(s), between inheriting the value of TZ from the environment and setting it at runtime. Using tzset() is the 'portable' thing to do. Okay, thanks. Didn't I answer an almost identical question from David a few months ago? Possibly. I had reported an issue with TZs not appearing to work on Debian, but if you said exactly the above, I missed it. Sorry. I'm glad to have the information now! Cheers, David -- David Wheeler AIM: dwTheory [EMAIL PROTECTED] ICQ: 15726394 http://www.kineticode.com/ Yahoo!: dew7e Jabber: [EMAIL PROTECTED] Kineticode. Setting knowledge in motion.[sm]
Re: Problem with DateTime::Format::DateManip v0.01
On Fri, 5 Sep 2003, David Wheeler wrote:
> Can you do another test for me (since I don't have a platform that
> needs tzset)? Can you tell me how it affects use of local? Here's a
> test script:
>
> #!/usr/bin/perl -w
> use strict;
> use POSIX qw(tzset);
>
> print scalar localtime, $/;
> {
> local $ENV{TZ} = "Asia/Tokyo";
> tzset;
> print scalar localtime, $/;
> }
> print scalar localtime, $/;
>
> The question is, what does the third print statement print? Do I need
> to call tzset again after the block?
Yep, you need to call it again. Whatever tzset does is something at a C
library level, not a Perl level, so the localization doesn't do anything.
-dave
/*===
House Absolute Consulting
www.houseabsolute.com
===*/
Re: Problem with DateTime::Format::DateManip v0.01
On Friday, September 5, 2003, at 09:51 AM, Dave Rolsky wrote:
Yep, you need to call it again. Whatever tzset does is something at a
C
library level, not a Perl level, so the localization doesn't do
anything.
Bah. Thanks for that. Does this work?
#!/usr/bin/perl -w
use strict;
use POSIX qw(tzset);
print scalar localtime, $/;
{
local $ENV{TZ} = "Asia/Tokyo";
tzset;
print scalar localtime, $/;
}
tzset;
print scalar localtime, $/;
Regards,
David
--
David Wheeler AIM: dwTheory
[EMAIL PROTECTED] ICQ: 15726394
http://www.kineticode.com/ Yahoo!: dew7e
Jabber: [EMAIL PROTECTED]
Kineticode. Setting knowledge in motion.[sm]
Re: Problem with DateTime::Format::DateManip v0.01
On Fri, 5 Sep 2003, David Wheeler wrote:
> Bah. Thanks for that. Does this work?
>
> #!/usr/bin/perl -w
>
> use strict;
> use POSIX qw(tzset);
> print scalar localtime, $/;
> {
> local $ENV{TZ} = "Asia/Tokyo";
> tzset;
> print scalar localtime, $/;
> }
> tzset;
> print scalar localtime, $/;
yup
/*===
House Absolute Consulting
www.houseabsolute.com
===*/
Re: Problem with DateTime::Format::DateManip v0.01
On Friday, September 5, 2003, at 11:21 AM, Dave Rolsky wrote: Bah. Thanks for that. Does this work? yup Oh, good, at least I don't have to stash the value away and reassign it. Thanks, David -- David Wheeler AIM: dwTheory [EMAIL PROTECTED] ICQ: 15726394 http://www.kineticode.com/ Yahoo!: dew7e Jabber: [EMAIL PROTECTED] Kineticode. Setting knowledge in motion.[sm]
