@ISA = qw(Exporter);
@EXPORT = qw(timegm timelocal);
-# timelocal.pl
-#
-# Usage:
-# $time = timelocal($sec,$min,$hours,$mday,$mon,$year);
-# $time = timegm($sec,$min,$hours,$mday,$mon,$year);
-
-# These routines are quite efficient and yet are always guaranteed to agree
-# with localtime() and gmtime(). We manage this by caching the start times
-# of any months we've seen before. If we know the start time of the month,
-# we can always calculate any time within the month. The start times
-# themselves are guessed by successive approximation starting at the
-# current time, since most dates seen in practice are close to the
-# current date. Unlike algorithms that do a binary search (calling gmtime
-# once for each bit of the time value, resulting in 32 calls), this algorithm
-# calls it at most 6 times, and usually only once or twice. If you hit
-# the month cache, of course, it doesn't call it at all.
-
-# timelocal is implemented using the same cache. We just assume that we're
-# translating a GMT time, and then fudge it when we're done for the timezone
-# and daylight savings arguments. The timezone is determined by examining
-# the result of localtime(0) when the package is initialized. The daylight
-# savings offset is currently assumed to be one hour.
-
-# Both routines return -1 if the integer limit is hit. I.e. for dates
-# after the 1st of January, 2038 on most machines.
-
-@epoch = localtime(0);
-$tzmin = $epoch[2] * 60 + $epoch[1]; # minutes east of GMT
-if ($tzmin > 0) {
- $tzmin = 24 * 60 - $tzmin; # minutes west of GMT
- $tzmin -= 24 * 60 if $epoch[5] == 70; # account for the date line
-}
+=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,$year);
+
+=head1 DESCRIPTION
+
+These routines are quite efficient and yet are always guaranteed to agree
+with localtime() and gmtime(). We manage this by caching the start times
+of any months we've seen before. If we know the start time of the month,
+we can always calculate any time within the month. The start times
+themselves are guessed by successive approximation starting at the
+current time, since most dates seen in practice are close to the
+current date. Unlike algorithms that do a binary search (calling gmtime
+once for each bit of the time value, resulting in 32 calls), this algorithm
+calls it at most 6 times, and usually only once or twice. If you hit
+the month cache, of course, it doesn't call it at all.
+
+timelocal is implemented using the same cache. We just assume that we're
+translating a GMT time, and then fudge it when we're done for the timezone
+and daylight savings arguments. The timezone is determined by examining
+the result of localtime(0) when the package is initialized. The daylight
+savings offset is currently assumed to be one hour.
+
+Both routines return -1 if the integer limit is hit. I.e. for dates
+after the 1st of January, 2038 on most machines.
+
+=cut
-$SEC = 1;
-$MIN = 60 * $SEC;
-$HR = 60 * $MIN;
-$DAYS = 24 * $HR;
-$YearFix = ((gmtime(946684800))[5] == 100) ? 100 : 0;
+BEGIN {
+ $SEC = 1;
+ $MIN = 60 * $SEC;
+ $HR = 60 * $MIN;
+ $DAY = 24 * $HR;
+ $epoch = (localtime(2*$DAY))[5]; # Allow for bugs near localtime == 0.
+
+ $YearFix = ((gmtime(946684800))[5] == 100) ? 100 : 0;
+
+ my $t = time;
+ my @lt = localtime($t);
+ my @gt = gmtime($t);
+
+ $tzsec = ($gt[1] - $lt[1]) * $MIN + ($gt[2] - $lt[2]) * $HR;
+
+ my($lday,$gday) = ($lt[7],$gt[7]);
+ if($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]);
+}
sub timegm {
$ym = pack(C2, @_[5,4]);
$cheat = $cheat{$ym} || &cheat;
- return -1 if $cheat<0;
- $cheat + $_[0] * $SEC + $_[1] * $MIN + $_[2] * $HR + ($_[3]-1) * $DAYS;
+ return -1 if $cheat<0 and $^O ne 'VMS';
+ $cheat + $_[0] * $SEC + $_[1] * $MIN + $_[2] * $HR + ($_[3]-1) * $DAY;
}
sub timelocal {
- $time = &timegm + $tzmin*$MIN;
- return -1 if $cheat<0;
+ $time = &timegm + $tzsec;
+ return -1 if $cheat<0 and $^O ne 'VMS';
@test = localtime($time);
$time -= $HR if $test[2] != $_[2];
$time;
sub cheat {
$year = $_[5];
+ $year -= 1900
+ if $year > 1900;
$month = $_[4];
- croak "Month out of range 0..11 in timelocal.pl"
- if $month > 11 || $month < 0;
- croak "Day out of range 1..31 in timelocal.pl"
- if $_[3] > 31 || $_[3] < 1;
- croak "Hour out of range 0..23 in timelocal.pl"
- if $_[2] > 23 || $_[2] < 0;
- croak "Minute out of range 0..59 in timelocal.pl"
- if $_[1] > 59 || $_[1] < 0;
- croak "Second out of range 0..59 in timelocal.pl"
- if $_[0] > 59 || $_[0] < 0;
+ croak "Month '$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);
- $year += $YearFix if $year < $epoch[5];
+ $year += $YearFix if $year < $epoch;
$lastguess = "";
while ($diff = $year - $g[5]) {
- $guess += $diff * (363 * $DAYS);
+ $guess += $diff * (363 * $DAY);
@g = gmtime($guess);
if (($thisguess = "@g") eq $lastguess){
return -1; #date beyond this machine's integer limit
$lastguess = $thisguess;
}
while ($diff = $month - $g[4]) {
- $guess += $diff * (27 * $DAYS);
+ $guess += $diff * (27 * $DAY);
@g = gmtime($guess);
if (($thisguess = "@g") eq $lastguess){
return -1; #date beyond this machine's integer limit
return -1; #date beyond this machine's integer limit
}
$g[3]--;
- $guess -= $g[0] * $SEC + $g[1] * $MIN + $g[2] * $HR + $g[3] * $DAYS;
+ $guess -= $g[0] * $SEC + $g[1] * $MIN + $g[2] * $HR + $g[3] * $DAY;
$cheat{$ym} = $guess;
}
projects / p5sagit/p5-mst-13.2.git / blobdiff