Merge pull request #2 from mbeijen/ntp

Added NTP epoch formatter.

example/ntptime.pl

@@ -0,0 +1,25 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use v5.10;
+
+use DateTime::Format::Epoch::NTP;
+use Socket;
+
+my $hostname = 'pool.ntp.org';
+socket(SOCKET, PF_INET, SOCK_DGRAM, getprotobyname('udp'));
+my $ipaddr = inet_aton($hostname);
+my $portaddr = sockaddr_in(123, $ipaddr);
+my $bstr = "\010" . "\0"x47;
+send(SOCKET, $bstr, 0, $portaddr);
+$portaddr = recv(SOCKET, $bstr, 1024, 0);
+my @words = unpack("N12",$bstr);
+my $ntptime = $words[10];
+
+my $dt = DateTime::Format::Epoch::NTP->parse_datetime( $ntptime );
+
+$dt->set_time_zone('Europe/Moscow');
+
+say "NTPTime $ntptime is in Moscow: " . $dt->hms;
+say $dt->datetime;

lib/DateTime/Format/Epoch/NTP.pm

@@ -0,0 +1,88 @@
+package DateTime::Format::Epoch::NTP;
+
+use strict;
+use warnings;
+
+use vars qw($VERSION @ISA);
+
+$VERSION = '0.14';
+
+use DateTime;
+use DateTime::Format::Epoch;
+
+@ISA = qw/DateTime::Format::Epoch/;
+
+my $epoch = DateTime->new( year => 1900, month => 1, day => 1,
+                           time_zone => 'UTC' );
+
+sub new {
+	my $class = shift;
+
+    return $class->SUPER::new( epoch => $epoch,
+                               unit  => 'seconds',
+                               type  => 'int',
+                               skip_leap_seconds => 1 );
+}
+
+1;
+__END__
+
+=head1 NAME
+
+DateTime::Format::Epoch::NTP - Convert DateTimes to/from NTP epoch seconds
+
+=head1 SYNOPSIS
+
+  use DateTime::Format::Epoch::NTP;
+
+  my $dt = DateTime::Format::Epoch::NTP->parse_datetime( 3629861151 );
+  print $dt->datetime; # '2015-01-10T06:45:51'
+
+  my $formatter = DateTime::Format::Epoch::NTP->new();
+  my $dt = DateTime->new( year => 2015, month => 1, day => 10,
+    time_zone => 'Europe/Amsterdam' );
+  print $formatter->format_datetime($dt); # '3629833200'
+
+=head1 DESCRIPTION
+
+This module can convert a DateTime object (or any object that can be
+converted to a DateTime object) to the number of seconds since the NTP
+epoch.
+
+The NTP epoch uses UTC; if you parse an NTP date your DateTime object
+will be using the UTC timezone.
+
+=head1 METHODS
+
+Most of the methods are the same as those in L<DateTime::Format::Epoch>.
+The only difference is the constructor.
+
+=over 4
+
+=item * new()
+
+Constructor of the formatter/parser object. It has no parameters.
+
+=back
+
+=head1 SUPPORT
+
+Support for this module is provided via the datetime@perl.org email
+list. See http://lists.perl.org/ for more details.
+
+=head1 AUTHOR
+
+Eugene van der Pijll <pijll@gmx.net>
+
+=head1 COPYRIGHT
+
+Copyright (c) 2015 Michiel Beijen. This program is free software; you can
+redistribute it and/or modify it under the same terms as Perl itself.
+
+=head1 SEE ALSO
+
+L<DateTime>
+
+datetime@perl.org mailing list
+
+=cut

t/502_format.t

@@ -6,6 +6,7 @@ use Test::More qw/no_plan/;
 use DateTime;
 use DateTime::Format::Epoch::JD;
 use DateTime::Format::Epoch::MJD;
+use DateTime::Format::Epoch::NTP;
 use DateTime::Format::Epoch::TJD;
 use DateTime::Format::Epoch::RJD;
 use DateTime::Format::Epoch::Lilian;
@@ -16,6 +17,7 @@ my $dt = DateTime->new( year => 2004, month => 8, day => 28 );
 my %dates = (
     JD  =>  2453245.5,
     MJD =>    53245,
+    NTP =>    3302640000,
     TJD =>    13245,
     RJD =>    53245.5,
     Lilian => 154086,

t/701_load.t

@@ -0,0 +1,5 @@
+# t/001_load.t - check module loading
+
+use Test::More tests => 1;
+
+BEGIN { use_ok( 'DateTime::Format::Epoch::NTP' ); }

t/702_format.t

@@ -0,0 +1,19 @@
+use strict;
+BEGIN { $^W = 1 }
+
+use Test::More tests => 4;
+use DateTime;
+use DateTime::Format::Epoch::NTP;
+
+my $f = DateTime::Format::Epoch::NTP->new();
+
+isa_ok($f, 'DateTime::Format::Epoch::NTP' );
+
+my $dt = DateTime->new( year => 2015, month => 1, day => 10,
+time_zone => 'Europe/Amsterdam' );
+is($f->format_datetime($dt), '3629833200', 'Format DateTime as NTP epoch time');
+
+$dt = DateTime::Format::Epoch::NTP->parse_datetime( 3629848426 );
+
+is($dt->iso8601(), '2015-01-10T03:13:46', 'read NTP time');
+is($dt->time_zone_long_name(), 'UTC', 'NPT time timezone is UTC');