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Wrong time base in Time::Piece? + other bugs

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Christian Jaeger
November 12, 2003 14:27
Wrong time base in Time::Piece? + other bugs
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I don't understand this:

use strict;
use Time::Piece;
my $time=time();
print "time=$time\n";
my $d= Time::Piece->strptime($time,'%s');
my $epoch= $d->epoch;
print "epoch=$epoch\n";
print "diff: ".($time-$epoch)."\n";

diff: -3600

Why is there a difference? Is this a bug in the %s parsing function 
(this is on (not fully current) Debian unstable, glibc 2.3.2, 
Time::Piece 1.08), or does Time::Piece use a wrong base for it's 
internal time storage format?

shows +0100 as time zone value (which I think is correct).

As far as I understand, all parsing functions seem to assume 
localtime (at least that's what it looks like when seeing +0100 as 
%z); but the epoch value also returns a time that is "based" on 
1970-1-1T0:00 localtime, same thing with %s parsing, while unixtime 
should be based on 1970-1-1T0:00 GMT, right?

BTW there are two (other) bugs in Time::Piece:

- it blesses to Time::Piece instead of the $class value obtained from 
the method arguments. This makes it necessary for subclasses to 
override all creators and rebless the objects after calling the 
SUPER:: creator.

- iirc, some methods modify the object itself, but return a copy of 
it - or something similar - which is silly, since you think, "oh, I 
got a copy, so I can still use the old one with the old value?", but 
it's wrong, and if you think, "oh, it modified my old object - let's 
modify the returned object again, it will change my original object 
again", and it's wrong, too. I'd have to dig about it for a test case 
if needed.


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