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Diffstat (limited to 'Master/tlpkg/tlperl.old/lib/Time/Local.pm')
| -rw-r--r-- | Master/tlpkg/tlperl.old/lib/Time/Local.pm | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/Master/tlpkg/tlperl.old/lib/Time/Local.pm b/Master/tlpkg/tlperl.old/lib/Time/Local.pm new file mode 100644 index 00000000000..912f17d0310 --- /dev/null +++ b/Master/tlpkg/tlperl.old/lib/Time/Local.pm @@ -0,0 +1,366 @@ +package Time::Local; + +require Exporter; +use Carp; +use Config; +use strict; +use integer; + +use vars qw( $VERSION @ISA @EXPORT @EXPORT_OK ); +$VERSION = '1.11'; +$VERSION = eval $VERSION; +@ISA = qw( Exporter ); +@EXPORT = qw( timegm timelocal ); +@EXPORT_OK = qw( timegm_nocheck timelocal_nocheck ); + +my @MonthDays = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31); + +# Determine breakpoint for rolling century +my $ThisYear = (localtime())[5]; +my $Breakpoint = ($ThisYear + 50) % 100; +my $NextCentury = $ThisYear - $ThisYear % 100; + $NextCentury += 100 if $Breakpoint < 50; +my $Century = $NextCentury - 100; +my $SecOff = 0; + +my (%Options, %Cheat, %Min, %Max); +my ($MinInt, $MaxInt); + +if ($^O eq 'MacOS') { + # time_t is unsigned... + $MaxInt = (1 << (8 * $Config{intsize})) - 1; + $MinInt = 0; +} else { + $MaxInt = ((1 << (8 * $Config{intsize} - 2))-1)*2 + 1; + $MinInt = -$MaxInt - 1; + + # On Win32 (and others?) time_t appears to be signed, but negative + # epochs still don't work. - XXX - this is experimental + $MinInt = 0 + unless defined ((localtime(-1))[0]); +} + +$Max{Day} = ($MaxInt >> 1) / 43200; +$Min{Day} = $MinInt ? -($Max{Day} + 1) : 0; + +$Max{Sec} = $MaxInt - 86400 * $Max{Day}; +$Min{Sec} = $MinInt - 86400 * $Min{Day}; + +# Determine the EPOC day for this machine +my $Epoc = 0; +if ($^O eq 'vos') { +# work around posix-977 -- VOS doesn't handle dates in +# the range 1970-1980. + $Epoc = _daygm((0, 0, 0, 1, 0, 70, 4, 0)); +} +elsif ($^O eq 'MacOS') { + no integer; + + # MacOS time() is seconds since 1 Jan 1904, localtime + # so we need to calculate an offset to apply later + $Epoc = 693901; + $SecOff = timelocal(localtime(0)) - timelocal(gmtime(0)); + $Epoc += _daygm(gmtime(0)); +} +else { + $Epoc = _daygm(gmtime(0)); +} + +%Cheat=(); # clear the cache as epoc has changed + +sub _daygm { + $_[3] + ($Cheat{pack("ss",@_[4,5])} ||= do { + my $month = ($_[4] + 10) % 12; + my $year = $_[5] + 1900 - $month/10; + 365*$year + $year/4 - $year/100 + $year/400 + ($month*306 + 5)/10 - $Epoc + }); +} + + +sub _timegm { + my $sec = $SecOff + $_[0] + 60 * $_[1] + 3600 * $_[2]; + + no integer; + + $sec + 86400 * &_daygm; +} + + +sub _zoneadjust { + my ($day, $sec, $time) = @_; + + $sec = $sec + _timegm(localtime($time)) - $time; + if ($sec >= 86400) { $day++; $sec -= 86400; } + if ($sec < 0) { $day--; $sec += 86400; } + + ($day, $sec); +} + + +sub timegm { + my ($sec,$min,$hour,$mday,$month,$year) = @_; + + if ($year >= 1000) { + $year -= 1900; + } + elsif ($year < 100 and $year >= 0) { + $year += ($year > $Breakpoint) ? $Century : $NextCentury; + } + + unless ($Options{no_range_check}) { + if (abs($year) >= 0x7fff) { + $year += 1900; + croak "Cannot handle date ($sec, $min, $hour, $mday, $month, *$year*)"; + } + + croak "Month '$month' out of range 0..11" if $month > 11 or $month < 0; + + my $md = $MonthDays[$month]; +# ++$md if $month == 1 and $year % 4 == 0 and +# ($year % 100 != 0 or ($year + 1900) % 400 == 0); + ++$md unless $month != 1 or $year % 4 or !($year % 400); + + croak "Day '$mday' out of range 1..$md" if $mday > $md or $mday < 1; + croak "Hour '$hour' out of range 0..23" if $hour > 23 or $hour < 0; + croak "Minute '$min' out of range 0..59" if $min > 59 or $min < 0; + croak "Second '$sec' out of range 0..59" if $sec > 59 or $sec < 0; + } + + my $days = _daygm(undef, undef, undef, $mday, $month, $year); + my $xsec = $sec + $SecOff + 60*$min + 3600*$hour; + + unless ($Options{no_range_check} + or ($days > $Min{Day} or $days == $Min{Day} and $xsec >= $Min{Sec}) + and ($days < $Max{Day} or $days == $Max{Day} and $xsec <= $Max{Sec})) + { + warn "Day too small - $days > $Min{Day}\n" if $days < $Min{Day}; + warn "Day too big - $days > $Max{Day}\n" if $days > $Max{Day}; + warn "Sec too small - $days < $Min{Sec}\n" if $days < $Min{Sec}; + warn "Sec too big - $days > $Max{Sec}\n" if $days > $Max{Sec}; + $year += 1900; + croak "Cannot handle date ($sec, $min, $hour, $mday, $month, $year)"; + } + + no integer; + + $xsec + 86400 * $days; +} + + +sub timegm_nocheck { + local $Options{no_range_check} = 1; + &timegm; +} + + +sub timelocal { + # Adjust Max/Min allowed times to fit local time zone and call timegm + local ($Max{Day}, $Max{Sec}) = _zoneadjust($Max{Day}, $Max{Sec}, $MaxInt); + local ($Min{Day}, $Min{Sec}) = _zoneadjust($Min{Day}, $Min{Sec}, $MinInt); + my $ref_t = &timegm; + + # Calculate first guess with a one-day delta to avoid localtime overflow + my $delta = ($_[5] < 100)? 86400 : -86400; + my $loc_t = _timegm(localtime( $ref_t + $delta )) - $delta; + + # Is there a timezone offset from GMT or are we done + my $zone_off = $ref_t - $loc_t + or return $loc_t; + + # This hack is needed to always pick the first matching time + # during a DST change when time would otherwise be ambiguous + $zone_off -= 3600 if ($delta > 0 && $ref_t >= 3600); + + # Adjust for timezone + $loc_t = $ref_t + $zone_off; + + # Are we close to a DST change or are we done + my $dst_off = $ref_t - _timegm(localtime($loc_t)) + or return $loc_t; + + # Adjust for DST change + $loc_t += $dst_off; + + return $loc_t if $dst_off >= 0; + + # for a negative offset from GMT, and if the original date + # was a non-extent gap in a forward DST jump, we should + # now have the wrong answer - undo the DST adjust; + + my ($s,$m,$h) = localtime($loc_t); + $loc_t -= $dst_off if $s != $_[0] || $m != $_[1] || $h != $_[2]; + + $loc_t; +} + + +sub timelocal_nocheck { + local $Options{no_range_check} = 1; + &timelocal; +} + +1; + +__END__ + +=head1 NAME + +Time::Local - efficiently compute time from local and GMT time + +=head1 SYNOPSIS + + $time = timelocal($sec,$min,$hour,$mday,$mon,$year); + $time = timegm($sec,$min,$hour,$mday,$mon,$year); + +=head1 DESCRIPTION + +These routines are the inverse of built-in perl functions localtime() +and gmtime(). They accept a date as a six-element array, and return +the corresponding time(2) value in seconds since the system epoch +(Midnight, January 1, 1970 GMT on Unix, for example). This value can +be positive or negative, though POSIX only requires support for +positive values, so dates before the system's epoch may not work on +all operating systems. + +It is worth drawing particular attention to the expected ranges for +the values provided. The value for the day of the month is the actual day +(ie 1..31), while the month is the number of months since January (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, $hour, $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, 1964 would indicate the year +Martin Luther King won the Nobel prize, not the year 3864. + +=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. + +=head2 Ambiguous Local Times (DST) + +Because of DST changes, there are many time zones where the same local +time occurs for two different GMT times on the same day. For example, +in the "Europe/Paris" time zone, the local time of 2001-10-28 02:30:00 +can represent either 2001-10-28 00:30:00 GMT, B<or> 2001-10-28 +01:30:00 GMT. + +When given an ambiguous local time, the timelocal() function should +always return the epoch for the I<earlier> of the two possible GMT +times. + +=head2 Non-Existent Local Times (DST) + +When a DST change causes a locale clock to skip one hour forward, +there will be an hour's worth of local times that don't exist. Again, +for the "Europe/Paris" time zone, the local clock jumped from +2001-03-25 01:59:59 to 2001-03-25 03:00:00. + +If the timelocal() function is given a non-existent local time, it +will simply return an epoch value for the time one hour later. + +=head2 Negative Epoch Values + +Negative epoch (time_t) values are not officially supported by the +POSIX standards, so this module's tests do not test them. On some +systems, they are known not to work. These include MacOS (pre-OSX) +and Win32. + +On systems which do support negative epoch values, this module should +be able to cope with dates before the start of the epoch, down the +minimum value of time_t for the system. + +=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 +are calculated using a mathematical formula. Unlike other algorithms +that do multiple calls to gmtime(). + +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. + +=head1 BUGS + +The whole scheme for interpreting two-digit years can be considered a bug. + +=head1 SUPPORT + +Support for this module is provided via the datetime@perl.org +email list. See http://lists.perl.org/ for more details. + +Please submit bugs using the RT system at rt.cpan.org, or as a last +resort, to the datetime@perl.org list. + +=head1 AUTHOR + +This module is based on a Perl 4 library, timelocal.pl, that was +included with Perl 4.036, and was most likely written by Tom +Christiansen. + +The current version was written by Graham Barr. + +It is now being maintained separately from the Perl core by Dave +Rolsky, <autarch@urth.org>. + +=cut + |