releasing/cbrtools/perl/Net/Time.pm
changeset 607 378360dbbdba
parent 602 3145852acc89
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/releasing/cbrtools/perl/Net/Time.pm	Wed Jun 30 11:35:58 2010 +0800
@@ -0,0 +1,151 @@
+# Net::Time.pm
+#
+# Copyright (c) 1995-1998 Graham Barr <gbarr@pobox.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 = "2.09"; # $Id: //depot/libnet/Net/Time.pm#9 $
+
+$TIMEOUT = 120;
+
+sub _socket
+{
+ my($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;
+  }
+
+ return unless $me;
+
+ $me->send("\n")
+	if $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 = '';
+ my $offset = 0 | 0;
+
+ return undef
+	unless $s->recv($buf, length(pack("N",0)));
+
+ # unpack, we | 0 to ensure we have an unsigned
+ my $time = (unpack("N",$buf))[0] | 0;
+
+ # the time protocol return time in seconds since 1900, convert
+ # it to a the required format
+
+ if($^O eq "MacOS") {
+   # MacOS return seconds since 1904, 1900 was not a leap year.
+   $offset = (4 * 31536000) | 0;
+ }
+ else {
+   # otherwise return seconds since 1972, there were 17 leap years between
+   # 1900 and 1972
+   $offset =  (70 * 31536000 + 17 * 86400) | 0;
+ }
+
+ $time - $offset;
+}
+
+sub inet_daytime
+{
+ my $s = _socket('daytime',13,@_) || return undef;
+ my $buf = '';
+
+ $s->recv($buf, 1024) ? $buf
+    	              : undef;
+}
+
+1;
+
+__END__
+
+=head1 NAME
+
+Net::Time - time and daytime network client interface
+
+=head1 SYNOPSIS
+
+    use Net::Time qw(inet_time inet_daytime);
+
+    print inet_time();		# use default host from Net::Config
+    print inet_time('localhost');
+    print inet_time('localhost', 'tcp');
+
+    print inet_daytime();	# use default host from Net::Config
+    print inet_daytime('localhost');
+    print inet_daytime('localhost', 'tcp');
+
+=head1 DESCRIPTION
+
+C<Net::Time> provides subroutines that obtain the time on a remote machine.
+
+=over 4
+
+=item inet_time ( [HOST [, PROTOCOL [, TIMEOUT]]])
+
+Obtain the time on C<HOST>, or some default host if C<HOST> is not given
+or not defined, using the protocol as defined in RFC868. The optional
+argument C<PROTOCOL> should define the protocol to use, either C<tcp> or
+C<udp>. The result will be a time value in the same units as returned
+by time() or I<undef> upon failure.
+
+=item inet_daytime ( [HOST [, PROTOCOL [, TIMEOUT]]])
+
+Obtain the time on C<HOST>, or some default host if C<HOST> is not given
+or not defined, using the protocol as defined in RFC867. The optional
+argument C<PROTOCOL> should define the protocol to use, either C<tcp> or
+C<udp>. The result will be an ASCII string or I<undef> upon failure.
+
+=back
+
+=head1 AUTHOR
+
+Graham Barr <gbarr@pobox.com>
+
+=head1 COPYRIGHT
+
+Copyright (c) 1995-1998 Graham Barr. All rights reserved.
+This program is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
+=for html <hr>
+
+I<$Id: //depot/libnet/Net/Time.pm#9 $>
+
+=cut