In this chapter, we introduce to you
Perl
treatment of time and date by language.
There are several functions for processing time in Perl:
time()Function: returns the number of seconds accumulated since January 1, 1970localtime()Function: get local time zone timegmtime()Function: get Greenwich mean time
5.31.1. Current time and date #
Next, let’s take a look.
localtime()
function that returns the current time and date without arguments.
The following nine symbols represent different time and date parameters:
Sec, # seconds, 0 to 61
Min, # minutes, 0 to 59
Hour, # hours, 0 to 24
Mday, # days, 1 to 31
Mon, # month, 0 to 11
Year, # year, starting from 1900
Wday, # day of the week, 0-6,0 represents Sunday
Yday, # day of the year, 0-364365
Isdst # True if daylight saving time is valid
The example is shown as follows: The output of the above example is as follows: If you call the The output of the above example is as follows:Example #
#/ Usr/bin/ perl@months =Qw (January, February, March, April, May, June, July, August, September)
October, November, December)@ Days=qw (Sunday, Monday, Tuesday, Wednesday, Thursday, Friday)
Saturday; ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst)=localtime();
Print "$mday $months [$mon] $days [$wday] n";
June Sunday, December
localtime()
which returns the time when the system setsthe time zone for the current period. An example is as follows:Example #
#!/usr/bin/perl$datestring=localtime();print"Time date is：$datestring\\n";
Time date is：Sun Jun 12 11:27:31 2016
5.31.2. Greenwich mean time (GMT) #
Function The output of the above example is as follows: We can see from the example that there is a difference of 8 hours between Chinese time and Greenwich mean time.
gmtime()
vs.
localtime()
similar, but it returns standardGreenwich mean time.Example #
#/ Usr/bin/perl $local_ Datestring=localtime(); Print "The local time and
date are: $local_datestring n"$ Gmt_ Datestring=gmtime(); Print "GMT
Time and date: $gmt_ Datestring n ";
Local time and date: Sun Jun 12 11:32:14 2016
GMT time and date: Sun Jun 12 03:32:14 2016
5.31.3. Format date and time #
We can use it. The output of the above example is as follows:
localtime()
function to output the formatting time that needs to be established. Formatted output using
printf()
function:Example #
#!/usr/bin/perl($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)=
localtime();printf("Format Time：HH:MM:SS\\n");printf("%02d:%02d:%02d",$hour,$min,$sec);
Format Time：HH:MM:SS
11:35:23
5.31.4. New era time (Epoch Time) #
We can use it. The output of the above example is as follows: We can output a time format that we want: The output of the above example is as follows:
time()
function to get the time of the new era, which returns the number of seconds accumulated since January 1, 1970. Examples are as follows:Example #
#!/usr/bin/perl$epoc=time();print"
The cumulative number of seconds since January 1, 1970 is：$epoc\\n";
The cumulative number of seconds since January 1, 1970 is：1465702883
Example #
#/ Usr/bin/perl ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst)=localtime(); Print "
Current time and date:"; Printf ("% d -% d -% d
%d: % d:% d ", $year+1900, $mon+1, $mday, $hour, $min, $sec); print" n "; $epoc=time(); $epoc=$epoc-24 * 60 * 60#
One day's time seconds ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst)=localtime ($epoc);
Print "Yesterday time and date:"; Printf ("% d -% d -% d
%d: % d:% d ", $year+1900, $mon+1, $mday, $hour, $min, $sec); print" n ";
Current time and date: March 15, 2017 12:47:54
Yesterday's time and date: March 14, 2017 12:47:54
5.31.5. POSIX function
strftime()
#
Function
strftime()
we can format the time into the format we want.
The following table lists some formatted symbols
*
number indicates that you want to rely on local time:
Symbol | Description | Example |
|---|---|---|
%a | Abbreviation of day of the week (Sun..Sat) * | Thu |
%A | The full name of the week (Sunday..Saturday) * | Thursday |
%b | Abbreviation for month (Jan..Dec) * | Aug |
%B | Full name of the month (January..December) * | August |
%c | Date and time * | Thu Aug 23 14:55:02 2001 |
%C | The year is divided by 100 and rounded (00-99) | 20 |
%d | The day of a month (01-31) | 23 |
%D | Date, MM/DD/YY? Equivalent to% m/%d/%y | 08/23/01 |
%e | On the day of the month, fill in single digits with spaces (?1-31) | 23 |
%F | YYYY-MM-DD? The abbreviation is similar to?% Y-%m-%d | 37126 |
%g | The last two digits of the year (00-99) | 1 |
%g | Year | 2001 |
%h | Month abbreviation * (same as% b option) | Aug |
%H | 24-hour system (00-23) | 14 |
%I | 12-hour system (01-12) | 2 |
%j | The day of the year (001-366) | 235 |
%m | Month (01-12) | 8 |
% M | Minutes (00-59) | 55 |
%n | New line (’n’) | |
%p | Show AM or PM | PM |
%r | Time (hh:mm:ss AM or PM), 12 hours * | 0.621550926 |
%R | 24 hours? HH:MM? Time format, which is equal to?% HRV% M | 0.621527778 |
%S | Seconds (00-61) | 2 |
%t | Horizontal tab (’t’) | |
%T | Time (24-hour system) (hh:mm:ss), equivalent to% H:%M:%S | 0.621527778 |
%u | What day format is ISO 8601, Monday is 1? (1-7) | 4 |
%U | The week ordinal of the year, Sunday is the first day (00-53) | 33 |
%V | Week of ISO 8601 (00-53) | 34 |
%w | The day of the week (0 represents Sunday) (0-6) | 4 |
%W | The week ordinal of the year, Monday is the first day (00-53) | 34 |
%x | Display date format (mm/dd/yy) * | 08/23/01 |
%X | Display time format * | 0.621550926 |
%y | Year, double digits (00-99) | 1 |
%Y | Year | 2001 |
%z | Time zone offset between ISO 8601 and UTC (1 minute=1, 1 hour=100) | 100 |
%Z | Name of the current time zone, such as “China Standard time” * | CDT |
%% | %? Symbol | % |
Example #
#/ Usr/bin/perluse POSIXqw (strftime)$ Datestring=strftime "% Y -% m -% d
%H: % M:% S ", localtime; printf (" time date - $datestring n "); # GMT
Format time date $datestring=strftime "% Y -% m -% d
%H: % M:% S ", gmtime; printf (" time date - $datestring n ");
The output of the above example is as follows:
Time and date - June 12, 2016 12:15:13
Time and date - June 12, 2016 04:15:13