Raku port of Perl's localtime / gmtime built-ins
# 0 1 2 3 4 5 6 7 8
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
say localtime(Scalar, time);
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday) = gmtime(time);
say gmtime(Scalar, time);
This module tries to mimic the behaviour of Perl's
gmtime built-ins as closely as possible in the Raku Programmming Language.
ORIGINAL PERL 5 DOCUMENTATION
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
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 $mon the month in the range
0..11, with 0 indicating January and 11 indicating December. This
makes it easy to get a month name from a list:
my @abbr = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);
print "$abbr[$mon] $mday";
# $mon=9, $mday=18 gives "Oct 18"
$year contains the number of years since 1900. To get a 4-digit
$year += 1900;
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"
The format of this scalar value is not locale-dependent but built
into Perl. For GMT instead of local time use the "gmtime" builtin.
See also the "Time::Local" module (for converting seconds,
minutes, hours, and such back to the integer value returned by
time()), and the POSIX module's strftime(3) and mktime(3)
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
The Time::gmtime and Time::localtime modules provide a convenient,
by-name access mechanism to the gmtime() and localtime()
For a comprehensive date and time representation look at the
DateTime module on CPAN.
Portability issues: "localtime" in perlport.
gmtime Works just like "localtime" but the returned values are localized
for the standard Greenwich time zone.
Note: When called in list context, $isdst, the last value returned
by gmtime, is always 0. There is no Daylight Saving Time in GMT.
Portability issues: "gmtime" in perlport.
Mimicking scalar context
Since Raku does not have a concept of scalar context, this must be mimiced by passing the
Scalar type as the first positional parameter.
The implementation actually also returns the offset in GMT in seconds as element number 9, and the name of the timezone as element number 10, if supported by the OS.
Depends on POSIX semantics
This module depends on the availability of POSIX semantics. This is generally not available on Windows, so this module will probably not work on Windows.
Elizabeth Mattijsen email@example.com
Source can be located at: https://github.com/lizmat/P5localtime . Comments and Pull Requests are welcome.
JJ Merelo, Jan-Olof Hendig, Tobias Leich, Timo Paulssen and Christoph (on StackOverflow) for support in getting this to work.
COPYRIGHT AND LICENSE
Copyright 2018, 2019, 2020, 2021 Elizabeth Mattijsen
Re-imagined from Perl as part of the CPAN Butterfly Plan.
This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.