[Perl] Epoch Time 구해기 (Uxix Time)

Perl에서 시간을 Unix time (Epoch Time)으로 전환하는 방법입니다.
Epoch Time은 1970-01-01 00:00:00 UTC 시간 이후로 지나간 second(초)를 계산한 것을 말합니다.
Perl에서는 이 시간으로 전환하고 다시 일반 date로 전환하는 방법이 간혹 필요합니다.
또한 RRD 데이터베이스에서는 이 Epoch Time으로 저장이 되므로, 반드시 필요합니다.
Linux나 AIX에서는커맨드라인에서 date 명령어 수행시 %s 옵션을 이용하여
Epoch Time을 구할 수 있습니다.(HP-UX에서는 없음)
 
 
How to convert epoch / UNIX timestamps to normal readable date/time using Perl.
 
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Getting current epoch time in Perl
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Time returns an integer with the current epoch:
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time
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Converting from epoch to normal date in Perl
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Using the internal localtime or gmtime functions, localtime and gmtime return an array:
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my $time = time; # or any other epoch timestamp
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my @months = ("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec");
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my ($sec, $min, $hour, $day,$month,$year) = (localtime($time))[0,1,2,3,4,5];
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# You can use 'gmtime' for GMT/UTC dates instead of 'localtime'
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print "Unix time ".$time." converts to ".$months[$month]." ".$day.", ".($year+1900);
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print " ".$hour.":".$min.":".$sec."\n";
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But you can also use the scalar function to display your date with far less code:
print scalar localtime(946684800);returns Sat Jan 1 01:00:00 2000 (in my timezone).
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For more advanced date manipulation, try using the DateTime module:
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use DateTime;
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$dt = DateTime->from_epoch( epoch => $epoch );
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$year = $dt->year;
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$month = $dt->month; # 1-12 - you can also use '$dt->mon'
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$day = $dt->day; # 1-31 - also 'day_of_month', 'mday'
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$dow = $dt->day_of_week; # 1-7 (Monday is 1) - also 'dow', 'wday'
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$hour = $dt->hour; # 0-23
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$minute = $dt->minute; # 0-59 - also 'min'
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$second = $dt->second; # 0-61 (leap seconds!) - also 'sec'
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$doy = $dt->day_of_year; # 1-366 (leap years) - also 'doy'
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$doq = $dt->day_of_quarter; # 1.. - also 'doq'
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$qtr = $dt->quarter; # 1-4
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$ymd = $dt->ymd; # 1974-11-30
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$ymd = $dt->ymd('/'); # 1974/11/30 - also 'date'
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$hms = $dt->hms; # 13:30:00
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$hms = $dt->hms('|'); # 13|30|00 - also 'time'
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Converting from normal date to epoch in Perl
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Using the Time::Local module:
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use Time::Local;
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my $time = timelocal($sec,$min,$hours,$day,$month,$year);
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# replace 'timelocal' with 'timegm' if your input date is GMT/UTC
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Using the DateTime module:
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use DateTime;
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$dt = DateTime->new( year => 1974, month => 11, day => 30, hour => 13, minute => 30,
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second => 0, nanosecond => 500000000, time_zone => 'Asia/Taipei' );
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$epoch_time = $dt->epoch;
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Find more detailed information on CPAN: Time::Local,DateTime. You can also use Date::Manip if you need more advanced date manipulation routines.
Using the Date::Parse module (thanks to ericblue76):
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use Date::Parse;
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print str2time("02/25/2011 11:50AM");
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The Perl Cookbook, Second Editiongives detailed information on manipulating dates and times in chapter 3 (pages 90-110).
 
 
 
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Epoch Time을 구하는 방법에는 여러가지 방법이 존재하는데, 아래는 그 예제들입니다.
 
 
Note that the month starts out as 0 for some inscrutable reason, so you'll have use
timelocal($sec,$min,$hours,$day,$month-1,$year); to get this to work.