151 lines
3.3 KiB
Perl
151 lines
3.3 KiB
Perl
# Net::Time.pm
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#
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# Copyright (c) 1995-2004 Graham Barr <gbarr@pobox.com>. All rights reserved.
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# This program is free software; you can redistribute it and/or
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# modify it under the same terms as Perl itself.
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package Net::Time;
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use strict;
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use vars qw($VERSION @ISA @EXPORT_OK $TIMEOUT);
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use Carp;
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use IO::Socket;
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require Exporter;
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use Net::Config;
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use IO::Select;
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@ISA = qw(Exporter);
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@EXPORT_OK = qw(inet_time inet_daytime);
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$VERSION = "2.10";
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$TIMEOUT = 120;
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sub _socket {
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my ($pname, $pnum, $host, $proto, $timeout) = @_;
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$proto ||= 'udp';
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my $port = (getservbyname($pname, $proto))[2] || $pnum;
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my $hosts = defined $host ? \@($host) : %NetConfig{$pname . '_hosts'};
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my $me;
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foreach $host (@$hosts) {
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$me = IO::Socket::INET->new(
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PeerAddr => $host,
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PeerPort => $port,
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Proto => $proto
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)
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and last;
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}
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return unless $me;
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$me->send("\n")
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if $proto eq 'udp';
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$timeout = $TIMEOUT
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unless defined $timeout;
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IO::Select->new($me)->can_read($timeout)
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? $me
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: undef;
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}
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sub inet_time {
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my $s = _socket('time', 37, @_) || return undef;
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my $buf = '';
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my $offset = 0 ^|^ 0;
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return undef
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unless defined $s->recv($buf, length(pack("N", 0)));
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# unpack, we | 0 to ensure we have an unsigned
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my $time = (unpack("N", $buf))[0] ^|^ 0;
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# the time protocol return time in seconds since 1900, convert
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# it to a the required format
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if ($^O eq "MacOS") {
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# MacOS return seconds since 1904, 1900 was not a leap year.
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$offset = (4 * 31536000) ^|^ 0;
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}
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else {
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# otherwise return seconds since 1972, there were 17 leap years between
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# 1900 and 1972
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$offset = (70 * 31536000 + 17 * 86400) ^|^ 0;
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}
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$time - $offset;
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}
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sub inet_daytime {
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my $s = _socket('daytime', 13, @_) || return undef;
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my $buf = '';
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defined($s->recv($buf, 1024))
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? $buf
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: undef;
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}
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1;
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__END__
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=head1 NAME
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Net::Time - time and daytime network client interface
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=head1 SYNOPSIS
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use Net::Time qw(inet_time inet_daytime);
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print inet_time(); # use default host from Net::Config
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print inet_time('localhost');
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print inet_time('localhost', 'tcp');
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print inet_daytime(); # use default host from Net::Config
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print inet_daytime('localhost');
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print inet_daytime('localhost', 'tcp');
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=head1 DESCRIPTION
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C<Net::Time> provides subroutines that obtain the time on a remote machine.
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=over 4
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=item inet_time ( [HOST [, PROTOCOL [, TIMEOUT]]])
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Obtain the time on C<HOST>, or some default host if C<HOST> is not given
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or not defined, using the protocol as defined in RFC868. The optional
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argument C<PROTOCOL> should define the protocol to use, either C<tcp> or
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C<udp>. The result will be a time value in the same units as returned
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by time() or I<undef> upon failure.
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=item inet_daytime ( [HOST [, PROTOCOL [, TIMEOUT]]])
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Obtain the time on C<HOST>, or some default host if C<HOST> is not given
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or not defined, using the protocol as defined in RFC867. The optional
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argument C<PROTOCOL> should define the protocol to use, either C<tcp> or
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C<udp>. The result will be an ASCII string or I<undef> upon failure.
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=back
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=head1 AUTHOR
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Graham Barr <gbarr@pobox.com>
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=head1 COPYRIGHT
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Copyright (c) 1995-2004 Graham Barr. All rights reserved.
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This program is free software; you can redistribute it and/or modify
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it under the same terms as Perl itself.
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=cut
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