Re^2: Date conversion in perl?

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Re^3: Date conversion in perl? by almut (Canon) on Mar 03, 2010 at 08:15 UTC
`$ perl -le 'print scalar(localtime(20100302165019));' Mon Mar 22 05:03:39 638923 ^^ ^^^^^^` [download] (with a 64-bit Perl) The string `'20100302165019'` doesn't represent seconds since "the epoch", which is what `localtime()` would expect.	[reply] [d/l] [select]
Re^3: Date conversion in perl? by ikegami (Patriarch) on Mar 03, 2010 at 08:22 UTC
No. That's not the what `localtime` takes for input. And even if it did, `localtime` does not produce the requested output. In fact, that number is so large that it doesn't fit in a 32-bit int, and thus my `localtime` can't handle it: `>perl -wle"print scalar(localtime(20100302165019));" Use of uninitialized value in print at -e line 1.` [download]	[reply] [d/l] [select]
Re^4: Date conversion in perl? by ww (Archbishop) on Mar 03, 2010 at 13:49 UTC
`ww@GIG:~$ perl -wle 'print scalar(localtime(20100302165019));' Wed Dec 31 18:59:59 1969 ww@GIG:~$ perl -wle 'print scalar(localtime(20100302165219));' Wed Dec 31 18:59:59 1969 ^ ww@GIG:~$ perl -wle 'print scalar(localtime(20100305165219));' Wed Dec 31 18:59:59 1969 ^ ww@GIG:~$ perl -wle 'print scalar(localtime(23100305165219));' Wed Dec 31 18:59:59 1969 ^` [download] 32bit 5.10 Linux	[reply] [d/l]
Re^5: Date conversion in perl? by bart (Canon) on Mar 03, 2010 at 14:11 UTC
FYI that date, 1 second before epoch, corresponds with a time value -1 (hex FFFFFFFF) which is commonly used as an overflow value for integer arithmetic.	[reply]
Re^5: Date conversion in perl? by ikegami (Patriarch) on Mar 03, 2010 at 15:59 UTC
It's a different failure mode, but it's still failing by returning the date for -1 instead of returning undef. I imagine that some of the work in this area is done by the underlying C library, so you can expect differences between systems. I believe that might also be changed in 5.12 to avoid the year 2038 overflow. Update: Confirmed: `$ /usr/bin/perl -le'print scalar localtime "201003031234"' Wed Dec 31 18:59:59 1969 $ ./perl -le'print scalar localtime "201003031234"' Fri Jul 14 19:20:34 8339` [download]	[reply] [d/l]
Re^3: Date conversion in perl? by Utilitarian (Vicar) on Mar 03, 2010 at 08:58 UTC
Not a unix epoch date `$ perl -e '$time_array = ["2010", "03", "02", "16", "50", "19"]; print @{$time_array};' 20100302165019` [download] `print "Good ",qw(night morning afternoon evening)[(localtime)[2]/6]," fellow monks."`	[reply] [d/l] [select]