如何在Perl中获取本周的日期？

Question

我使用以下循环来计算当前周的日期并将其打印出来。它是有效的，但是我正在处理Perl中大量的日期/时间可能性，并希望了解您对是否有更好的方法的看法。下面是我写的代码：

#!/usr/bin/env perl
use warnings;
use strict;

use DateTime;

# Calculate numeric value of today and the 
# target day (Monday = 1, Sunday = 7); the
# target, in this case, is Monday, since that's
# when I want the week to start
my $today_dt = DateTime->now;
my $today = $today_dt->day_of_week;
my $target = 1;

# Create DateTime copies to act as the "bookends"
# for the date range
my ($start, $end) = ($today_dt->clone(), $today_dt->clone());

if ($today == $target)
{
  # If today is the target, "start" is already set;
  # we simply need to set the end date
  $end->add( days => 6 );
}
else
{
  # Otherwise, we calculate the Monday preceeding today
  # and the Sunday following today
  my $delta = ($target - $today + 7) % 7;
  $start->add( days => $delta - 7 );
  $end->add( days => $delta - 1 );
}

# I clone the DateTime object again because, for some reason,
# I'm wary of using $start directly...
my $cur_date = $start->clone();

while ($cur_date <= $end)
{
  my $date_ymd = $cur_date->ymd;
  print "$date_ymd\n";
  $cur_date->add( days => 1 );
}

正如前面提到的，这是可行的，但它是最快的还是最有效的？我猜速度和效率可能不一定会结合在一起，但您的反馈非常感谢。

Answer 1

对friedo的回答稍加改进的版本...

my $start_of_week =
    DateTime->today()
            ->truncate( to => 'week' );

for ( 0..6 ) {
    print $start_of_week->clone()->add( days => $_ );
}

但是，这假设星期一是一周的第一天。星期天，从……开始。

my $start_of_week =
    DateTime->today()
            ->truncate( to => 'week' )
            ->subtract( days => 1 );

无论哪种方式，最好使用truncate方法，而不是像friedo那样重新实现它;)

Answer 2

可以使用DateTime对象以数字( 1-7 )的形式获取一周中的当前日期。然后只需使用它来查找当前周的星期一。例如：

my $today = DateTime->now;
my $start = $today->clone;

# move $start to Monday
$start->subtract( days => ( $today->wday - 1 ) );   # Monday gives 1, so on monday we
                                                    # subtract zero. 

my $end = $start->clone->add( days => 7 );

以上这些都是未经测试的，但是这个想法应该是可行的。

Answer 3

这样行得通吗：

use strict;
use warnings;
use POSIX qw<strftime>;
my ( $day, $pmon, $pyear, $wday ) = ( localtime )[3..6];
$day -= $wday - 1; # Get monday
for my $d ( map { $day + $_ } 0..6 ) { 
    print strftime( '%A, %B %d, %Y', ( 0 ) x 3, $d, $pmon, $pyear ), "\n";
}

我只是把它们打印出来作为说明。您可以将它们存储为时间戳，如下所示：

use POSIX qw<mktime>;
my @week = map { mktime(( 0 ) x 3, $day + $_, $pmon, $pyear ) } 0..6;