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Diffstat (limited to 'contrib/perl5/lib/Time/Local.pm')
| -rw-r--r-- | contrib/perl5/lib/Time/Local.pm | 246 |
1 files changed, 0 insertions, 246 deletions
diff --git a/contrib/perl5/lib/Time/Local.pm b/contrib/perl5/lib/Time/Local.pm deleted file mode 100644 index a480884..0000000 --- a/contrib/perl5/lib/Time/Local.pm +++ /dev/null @@ -1,246 +0,0 @@ -package Time::Local; -require 5.000; -require Exporter; -use Carp; - -@ISA = qw( Exporter ); -@EXPORT = qw( timegm timelocal ); -@EXPORT_OK = qw( timegm_nocheck timelocal_nocheck ); - -# Set up constants - $SEC = 1; - $MIN = 60 * $SEC; - $HR = 60 * $MIN; - $DAY = 24 * $HR; -# Determine breakpoint for rolling century - my $thisYear = (localtime())[5]; - $nextCentury = int($thisYear / 100) * 100; - $breakpoint = ($thisYear + 50) % 100; - $nextCentury += 100 if $breakpoint < 50; - -my %options; - -sub timegm { - my (@date) = @_; - if ($date[5] > 999) { - $date[5] -= 1900; - } - elsif ($date[5] >= 0 && $date[5] < 100) { - $date[5] -= 100 if $date[5] > $breakpoint; - $date[5] += $nextCentury; - } - $ym = pack(C2, @date[5,4]); - $cheat = $cheat{$ym} || &cheat(@date); - $cheat - + $date[0] * $SEC - + $date[1] * $MIN - + $date[2] * $HR - + ($date[3]-1) * $DAY; -} - -sub timegm_nocheck { - local $options{no_range_check} = 1; - &timegm; -} - -sub timelocal { - my $t = &timegm; - my $tt = $t; - - my (@lt) = localtime($t); - my (@gt) = gmtime($t); - if ($t < $DAY and ($lt[5] >= 70 or $gt[5] >= 70 )) { - # Wrap error, too early a date - # Try a safer date - $tt += $DAY; - @lt = localtime($tt); - @gt = gmtime($tt); - } - - my $tzsec = ($gt[1] - $lt[1]) * $MIN + ($gt[2] - $lt[2]) * $HR; - - if($lt[5] > $gt[5]) { - $tzsec -= $DAY; - } - elsif($gt[5] > $lt[5]) { - $tzsec += $DAY; - } - else { - $tzsec += ($gt[7] - $lt[7]) * $DAY; - } - - $tzsec += $HR if($lt[8]); - - $time = $t + $tzsec; - @test = localtime($time + ($tt - $t)); - $time -= $HR if $test[2] != $_[2]; - $time; -} - -sub timelocal_nocheck { - local $options{no_range_check} = 1; - &timelocal; -} - -sub cheat { - $year = $_[5]; - $month = $_[4]; - unless ($options{no_range_check}) { - croak "Month '$month' out of range 0..11" if $month > 11 || $month < 0; - croak "Day '$_[3]' out of range 1..31" if $_[3] > 31 || $_[3] < 1; - croak "Hour '$_[2]' out of range 0..23" if $_[2] > 23 || $_[2] < 0; - croak "Minute '$_[1]' out of range 0..59" if $_[1] > 59 || $_[1] < 0; - croak "Second '$_[0]' out of range 0..59" if $_[0] > 59 || $_[0] < 0; - } - $guess = $^T; - @g = gmtime($guess); - $lastguess = ""; - $counter = 0; - while ($diff = $year - $g[5]) { - croak "Can't handle date (".join(", ",@_).")" if ++$counter > 255; - $guess += $diff * (363 * $DAY); - @g = gmtime($guess); - if (($thisguess = "@g") eq $lastguess){ - croak "Can't handle date (".join(", ",@_).")"; - #date beyond this machine's integer limit - } - $lastguess = $thisguess; - } - while ($diff = $month - $g[4]) { - croak "Can't handle date (".join(", ",@_).")" if ++$counter > 255; - $guess += $diff * (27 * $DAY); - @g = gmtime($guess); - if (($thisguess = "@g") eq $lastguess){ - croak "Can't handle date (".join(", ",@_).")"; - #date beyond this machine's integer limit - } - $lastguess = $thisguess; - } - @gfake = gmtime($guess-1); #still being sceptic - if ("@gfake" eq $lastguess){ - croak "Can't handle date (".join(", ",@_).")"; - #date beyond this machine's integer limit - } - $g[3]--; - $guess -= $g[0] * $SEC + $g[1] * $MIN + $g[2] * $HR + $g[3] * $DAY; - $cheat{$ym} = $guess; -} - -1; - -__END__ - -=head1 NAME - -Time::Local - efficiently compute time from local and GMT time - -=head1 SYNOPSIS - - $time = timelocal($sec,$min,$hours,$mday,$mon,$year); - $time = timegm($sec,$min,$hours,$mday,$mon,$year); - -=head1 DESCRIPTION - -These routines are the inverse of built-in perl fuctions localtime() -and gmtime(). They accept a date as a six-element array, and return -the corresponding time(2) value in seconds since the Epoch (Midnight, -January 1, 1970). This value can be positive or negative. - -It is worth drawing particular attention to the expected ranges for -the values provided. While the day of the month is expected to be in -the range 1..31, the month should be in the range 0..11. -This is consistent with the values returned from localtime() and gmtime(). - -The timelocal() and timegm() functions perform range checking on the -input $sec, $min, $hours, $mday, and $mon values by default. If you'd -rather they didn't, you can explicitly import the timelocal_nocheck() -and timegm_nocheck() functions. - - use Time::Local 'timelocal_nocheck'; - - { - # The 365th day of 1999 - print scalar localtime timelocal_nocheck 0,0,0,365,0,99; - - # The twenty thousandth day since 1970 - print scalar localtime timelocal_nocheck 0,0,0,20000,0,70; - - # And even the 10,000,000th second since 1999! - print scalar localtime timelocal_nocheck 10000000,0,0,1,0,99; - } - -Your mileage may vary when trying these with minutes and hours, -and it doesn't work at all for months. - -Strictly speaking, the year should also be specified in a form consistent -with localtime(), i.e. the offset from 1900. -In order to make the interpretation of the year easier for humans, -however, who are more accustomed to seeing years as two-digit or four-digit -values, the following conventions are followed: - -=over 4 - -=item * - -Years greater than 999 are interpreted as being the actual year, -rather than the offset from 1900. Thus, 1963 would indicate the year -Martin Luther King won the Nobel prize, not the year 2863. - -=item * - -Years in the range 100..999 are interpreted as offset from 1900, -so that 112 indicates 2012. This rule also applies to years less than zero -(but see note below regarding date range). - -=item * - -Years in the range 0..99 are interpreted as shorthand for years in the -rolling "current century," defined as 50 years on either side of the current -year. Thus, today, in 1999, 0 would refer to 2000, and 45 to 2045, -but 55 would refer to 1955. Twenty years from now, 55 would instead refer -to 2055. This is messy, but matches the way people currently think about -two digit dates. Whenever possible, use an absolute four digit year instead. - -=back - -The scheme above allows interpretation of a wide range of dates, particularly -if 4-digit years are used. - -Please note, however, that the range of dates that can be actually be handled -depends on the size of an integer (time_t) on a given platform. -Currently, this is 32 bits for most systems, yielding an approximate range -from Dec 1901 to Jan 2038. - -Both timelocal() and timegm() croak if given dates outside the supported -range. - -=head1 IMPLEMENTATION - -These routines are quite efficient and yet are always guaranteed to agree -with localtime() and gmtime(). We manage this by caching the start times -of any months we've seen before. If we know the start time of the month, -we can always calculate any time within the month. The start times -themselves are guessed by successive approximation starting at the -current time, since most dates seen in practice are close to the -current date. Unlike algorithms that do a binary search (calling gmtime -once for each bit of the time value, resulting in 32 calls), this algorithm -calls it at most 6 times, and usually only once or twice. If you hit -the month cache, of course, it doesn't call it at all. - -timelocal() is implemented using the same cache. We just assume that we're -translating a GMT time, and then fudge it when we're done for the timezone -and daylight savings arguments. Note that the timezone is evaluated for -each date because countries occasionally change their official timezones. -Assuming that localtime() corrects for these changes, this routine will -also be correct. The daylight savings offset is currently assumed -to be one hour. - -=head1 BUGS - -The whole scheme for interpreting two-digit years can be considered a bug. - -Note that the cache currently handles only years from 1900 through 2155. - -The proclivity to croak() is probably a bug. - -=cut |
