perl:好用的localtime函数。

localtime EXPR
localtime

引用方法：
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime;

$sec,$min,$hour :  seconds, minutes, and hours of the specified time.
$mday               :  the day of the month 
$mon                 :  the month in the range 0..11 
$year                 :  contains the number of years since 1900.
                            To get a 4-digit year write            : $year += 1900;
                            To get the last two digits of the year : $year = sprintf("%02d", $year % 100);
$wday                 : the day of the week, with 0 indicating Sunday and 3 indicating Wednesday
$yday                  : the day of the year, in the range 0..364 (or 0..365 in leap years.)
$isdst                   : true if the specified time occurs during Daylight Saving Time, false otherwise.


一个栗子：

my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime;

my @aweek = qw(Sunday Monday Tuesday Wenday Thursday Friday Saturday);

my @aDayTS= qw(Not-Daytime-saving Daytimesaving);

print "今天是 ", $year +1900," 年", $mon +1," 月 $mday 号. 目前是$aDayTS[$isdst]。 \n", ;

print "Today is $aweek[$wday], is the ", $yday, "th days of this year.\n";

# to obtain the month and day:

my @abbr = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);

print "Today is : $abbr[$mon] $mday";

print "\n";

【output】

今天是 2019 年10 月 22 号. 目前是Not-Daytime-saving。 

Today is Tuesday, is the 294th days of this year.

Today is : Oct 22

#########
Note: If EXPR is omitted, localtime uses the current time (as returned by time).


尤其注意：
　在标量上下文中，localtime返回的的是ctime(3)的值（In scalar context, localtime returns the ctime(3) value）: 


 一个栗子：

print scalar localtime;

print "\n";

[output]:
Tue Oct 22 11:07:08 2019