48 lines
2.3 KiB
Plaintext
48 lines
2.3 KiB
Plaintext
The following information about Perl and the year 2000 is a modified
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version of the information that can be found in the Frequently Asked
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Question (FAQ) documents.
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Does Perl have a year 2000 problem? Is Perl Y2K compliant?
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Short answer: No, Perl does not have a year 2000 problem. Yes,
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Perl is Y2K compliant (whatever that means). The
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programmers you've hired to use it, however, probably are
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not. If you want perl to complain when your programmers
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create programs with certain types of possible year 2000
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problems, a build option allows you to turn on warnings.
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Long answer: The question belies a true understanding of the
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issue. Perl is just as Y2K compliant as your pencil
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--no more, and no less. Can you use your pencil to write
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a non-Y2K-compliant memo? Of course you can. Is that
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the pencil's fault? Of course it isn't.
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The date and time functions supplied with perl (gmtime and
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localtime) supply adequate information to determine the
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year well beyond 2000 (2038 is when trouble strikes for
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32-bit machines). The year returned by these functions
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when used in a list context is the year minus 1900. For
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years between 1910 and 1999 this happens to be a 2-digit
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decimal number. To avoid the year 2000 problem simply do
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not treat the year as a 2-digit number. It isn't.
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When gmtime() and localtime() are used in scalar context
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they return a timestamp string that contains a fully-
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expanded year. For example, $timestamp =
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gmtime(1005613200) sets $timestamp to "Tue Nov 13 01:00:00
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2001". There's no year 2000 problem here.
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That doesn't mean that Perl can't be used to create non-
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Y2K compliant programs. It can. But so can your pencil.
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It's the fault of the user, not the language. At the risk
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of inflaming the NRA: ``Perl doesn't break Y2K, people
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do.'' See http://language.perl.com/news/y2k.html for a
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longer exposition.
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If you want perl to warn you when it sees a program which
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catenates a number with the string "19" -- a common
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indication of a year 2000 problem -- build perl using the
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Configure option "-Accflags=-DPERL_Y2KWARN".
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(See the file INSTALL for more information about building
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perl.)
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