fixedtime - lexical pragma to fix the epoch offset for time related functions

    use Test::More 'no_plan';

    use constant EPOCH_OFFSET => 1204286400; # 29 Feb 2008 12:00:00 GMT

    {
        use fixedtime epoch_offset => EPOCH_OFFSET;

        my $fixstamp = time;
        is $fixstamp, EPOCH_OFFSET, "Fixed point in time ($fixstamp)";
        is scalar gmtime, "Fri Feb 29 12:00:00 2008",
           "@{[ scalar gmtime ]}";

        no fixedtime;
        isnt time, EPOCH_OFFSET, "time() is back to normal";
    }

    isnt time, EPOCH_OFFSET, "time() is back to normal";

This pragma demonstrates the new perl 5.10 user-defined lexical pragma capability. It uses the $^H{fixedtime} hintshash entry to store the epochoffset. Whenever $^H{fixedtime} is undefined, the praga is assumed not to be in effect.

The fixedtime pragma affects time(), gmtime() and localtime() only when called without an argument.

This will enable the pragma in the current lexical scope. When the epoch_offset argument is omitted, CORE::time() is taken. While the pragma is in effect the epochoffset is not changed.

Warning: If you use a variable to set the epoch offset, make sure it is initialized at compile time.

    my $epoch_offset = 1204286400;
    use fixedtime epoch_offset => $epoch_offset; # Will not work as expected

You will need something like:

    use constant EPOCH_OFFSET => 1204286400;
    use fixedtime epoch_offset => EPOCH_OFFSET;

This will disable the pragma in the current lexical scope.

perlpragma

(c) MMVIII All rights reserved, Abe Timmerman <abeltje@cpan.org>

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.