Perl/펄] 2자리수 년도 구하기, 두 자리 연도 출력; Two Digits Year

D:\Z>perldoc -f localtime
    localtime EXPR
    localtime
            Converts a time as returned by the time function to a 9-element
            list with the time analyzed for the local time zone. Typically
            used as follows:

                #  0    1    2     3     4    5     6     7     8
                ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
                                                            localtime(time);

            All list elements are numeric, and come straight out of the C
            `struct tm'. $sec, $min, and $hour are the seconds, minutes, and
            hours of the specified time.

            $mday is the day of the month, and $mon is the month itself, in
            the range 0..11 with 0 indicating January and 11 indicating
            December. This makes it easy to get a month name from a list:

                my @abbr = qw( Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec )
;
                print "$abbr[$mon] $mday";
                # $mon=9, $mday=18 gives "Oct 18"

            $year is the number of years since 1900, not just the last two
            digits of the year. That is, $year is 123 in year 2023. The
            proper way to get a 4-digit year is simply:

                $year += 1900;

            Otherwise you create non-Y2K-compliant programs--and you
            wouldn't want to do that, would you?

            To get the last two digits of the year (e.g., '01' in 2001) do:

                $year = sprintf("%02d", $year % 100);

            $wday is the day of the week, with 0 indicating Sunday and 3
            indicating Wednesday. $yday is the day of the year, in the range
            0..364 (or 0..365 in leap years.)

            $isdst is true if the specified time occurs during Daylight
            Saving Time, false otherwise.

            If EXPR is omitted, "localtime()" uses the current time (as
            returned by time(3)).

            In scalar context, "localtime()" returns the ctime(3) value:

                $now_string = localtime;  # e.g., "Thu Oct 13 04:54:34 1994"

            This scalar value is not locale dependent but is a Perl builtin.
            For GMT instead of local time use the "gmtime" builtin. See also
            the "Time::Local" module (to convert the second, minutes, hours,
            ... back to the integer value returned by time()), and the POSIX
            module's strftime(3) and mktime(3) functions.

            To get somewhat similar but locale dependent date strings, set
            up your locale environment variables appropriately (please see
            perllocale) and try for example:

                use POSIX qw(strftime);
                $now_string = strftime "%a %b %e %H:%M:%S %Y", localtime;
                # or for GMT formatted appropriately for your locale:
                $now_string = strftime "%a %b %e %H:%M:%S %Y", gmtime;

            Note that the %a and %b, the short forms of the day of the week
            and the month of the year, may not necessarily be three
            characters wide.

            See "localtime" in perlport for portability concerns.

            The Time::gmtime and Time::localtime modules provides a
            convenient, by-name access mechanism to the gmtime() and
            localtime() functions, respectively.

            For a comprehensive date and time representation look at the
            DateTime module on CPAN.


D:\Z>

D:\Z>0.pl
1985
85

D:\Z>0.pl
2007
07

D:\Z>