perl POSIX::strptime - 我的数据看起来像上午 9:31:00 - 我想提取分钟并执行计算

Question

我想从逗号分隔文件第二列中存在的指定时间中提取分钟并执行计算。时间的格式如下：

9:31:00 AM

我想提取分钟值并计算迄今为止一天中的总分钟数。我在子例程 get_time 中执行此操作。但返回值始终为零，这让我认为我没有正确使用 POSIX::strptime 。任何见解都会很棒。谢谢。

#!/usr/bin/env perl  
use strict;  
use POSIX::strptime;  
use Text::CSV;  

sub get_time  
{  
    my($str) = @_;
    my ($sec, $min, $hour) = (POSIX::strptime($str, '%I:%M:%S')) [3,4,5];
    print "$hour\n";
    return($hour*60 + $min)
}

open my $fh, "<", datafile.txt
my $csv = Text::CSV->new() or die "Failed to create Text::CSV object";
my $line = <$fh>;

die "Failed to parse line <<$line>>\n\n" unless $csv->parse($line);
my @columns = $csv->fields();

while ($line = <$fh>)
{
   chomp $line;
   die "Failed to parse line <<$line>>\n\n" unless $csv->parse($line);
   my @columns = $csv->fields();
   die "Insufficient columns in <<$line>>\n" if scalar(@columns) < 1;
   my $minute = get_time($columns[1]);
   print "$minute\n";
}

Answer 1

在 get_time 中，您有以下行

my ($sec, $min, $hour) = (POSIX::strptime($str, '%I:%M:%S')) [3,4,5];`

根据 docs, strptime 返回

($sec, $min, $hour, $mday, $mon, $year, $wday, $yday) = POSIX::strptime("string", "Format");

所以看起来您

my ($sec, $min, $hour) = (POSIX::strptime($str, '%I:%M:%S')) [0,1,2];

需要。

祝你好运！

Answer 2

如果不知道时区和可能的日期，就不可能正确确定一天中某个时间之前的分钟数。

$ perl -MDateTime -E'
   for (10..16) {
      my $dt = DateTime->new(
         year      => 2011,
         month     => 3,
         day       => $_,
         hour      => 9,
         minute    => 31,
         second    => 0,
         time_zone => "America/New_York",
      );
      ( my $ref_dt = $dt->clone )->truncate(to => "day");
      my $minutes = ($dt - $ref_dt)->in_units("minutes");
      say($dt->ymd, " ",  $minutes);
   }
'
2011-03-10 571
2011-03-11 571
2011-03-12 571
2011-03-13 511    <------
2011-03-14 571
2011-03-15 571
2011-03-16 571