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# Net::Time.pm
#
# Copyright (c) 1995-1997 Graham Barr <gbarr@ti.com>. All rights reserved.
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
package Net::Time;
use strict;
use vars qw($VERSION @ISA @EXPORT_OK $TIMEOUT);
use Carp;
use IO::Socket;
require Exporter;
use Net::Config;
use IO::Select;
@ISA = qw(Exporter);
@EXPORT_OK = qw(inet_time inet_daytime);
$VERSION = do { my @r=(q$Revision: 2.5 $=~/\d+/g); sprintf "%d."."%02d"x$#r,@r};
$TIMEOUT = 120;
sub _socket
{
my($pname,$pnum,$host,$proto,$timeout) = @_;
$proto ||= 'udp';
my $port = (getservbyname($pname, $proto))[2] || $pnum;
my $hosts = defined $host ? [ $host ] : $NetConfig{$pname . '_hosts'};
my $me;
foreach $host (@$hosts)
{
$me = IO::Socket::INET->new(PeerAddr => $host,
PeerPort => $port,
Proto => $proto
) and last;
}
$me->send("\n")
if(defined $me && $proto eq 'udp');
$timeout = $TIMEOUT
unless defined $timeout;
IO::Select->new($me)->can_read($timeout)
? $me
: undef;
}
sub inet_time
{
my $s = _socket('time',37,@_) || return undef;
my $buf = '';
# the time protocol return time in seconds since 1900, convert
# it to a unix time (seconds since 1970)
$s->recv($buf, length(pack("N",0)))
? (unpack("N",$buf))[0] - 2208988800
: undef;
}
sub inet_daytime
{
my $s = _socket('daytime',13,@_) || return undef;
my $buf = '';
$s->recv($buf, 1024) ? $buf
: undef;
}
1;
__END__
=head1 NAME
Net::Time - time and daytime network client interface
=head1 SYNOPSIS
use Net::Time qw(inet_time inet_daytime);
print inet_time(); # use default host from Net::Config
print inet_time('localhost');
print inet_time('localhost', 'tcp');
print inet_daytime(); # use default host from Net::Config
print inet_daytime('localhost');
print inet_daytime('localhost', 'tcp');
=head1 DESCRIPTION
C<Net::Time> provides subroutines that obtain the time on a remote machine.
=over 4
=item inet_time ( [HOST [, PROTOCOL [, TIMEOUT]]])
Obtain the time on C<HOST>, or some default host if C<HOST> is not given
or not defined, using the protocol as defined in RFC868. The optional
argument C<PROTOCOL> should define the protocol to use, either C<tcp> or
C<udp>. The result will be a unix-like time value or I<undef> upon
failure.
=item inet_daytime ( [HOST [, PROTOCOL [, TIMEOUT]]])
Obtain the time on C<HOST>, or some default host if C<HOST> is not given
or not defined, using the protocol as defined in RFC867. The optional
argument C<PROTOCOL> should define the protocol to use, either C<tcp> or
C<udp>. The result will be an ASCII string or I<undef> upon failure.
=back
=head1 AUTHOR
Graham Barr <gbarr@ti.com>
=head1 COPYRIGHT
Copyright (c) 1995-1997 Graham Barr. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut
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