}

sub canceled {
    my $self = shift;
    my $watcher = shift;
    $self->addempty;
    $self->{Canceled} = 1;
    $try_later{$self->{Host}} = $self;
    $self->{Watcher} = $watcher;
}

} # package
######################################################################
# hostgroups

sub hostgroup_cpan {
    qw(ftp.gmd.de
       ftp.gwdg.de
       ftp.leo.org
       ftp.mpi-sb.mpg.de
       ftp.rz.ruhr-uni-bochum.de
       ftp.uni-erlangen.de
       ftp.uni-hamburg.de
       ftp.digital.com
       ftp.cdrom.com
       www.perl.org
       www.cpan.org
    );
}

sub hostgroup_freebsd {
    qw(ftp.cs.tu-berlin.de
       ftp.freebsd.org
       ftp.freebsd.de
       ftp2.freebsd.org
       ftp3.freebsd.org
    );
}

sub hostgroup_linux {
    qw(www.linux.org www.rpmfind.net www.redhat.com
       www.suse.de www.mandrake.com);
}

sub hostgroup_search {
    qw(www.altavista.com
       www.altavista.de
       www.yahoo.com
       www.infoseek.com
       www.hotbot.com
       www.lycos.com
       www.lycos.de
       www.dejanews.com
       search.opentext.com
       home.netscape.com
       webcrawler.com
       netguide.de
       www.web.de
       www.fireball.de
       www.hurra.de
       suchen.com
       mserv.rrzn.uni-hannover.de
    );
}

sub hostgroup_default {
    (qw(www.altavista.com
       www.google.com
       www.perl.com
       www.linux.org
       ftp.perl.org),
     ['www.sourceforge.net', 'http'],
     ['www.netscape.com', 'http'],
     ['www.microsoft.com', 'http'],
     ['www.freebsd.org', 'http'],
     ['www.cpan.org', 'http'],
     ['www.yahoo.com', 'http'],
     ['www.amazon.com', 'http'],
     ['www.gnu.org', 'http'],
     ['ftp.funet.fi', 'http'],
     ['www.slashdot.org', 'http'],
     ['www.heise.de', 'http'],
    );
}

*hostgroup_normal = *hostgroup_normal = \&hostgroup_default;

######################################################################
# main

my $hostgroup = "normal";
my @addhost;
my $do_ns = 1;
my $hostfile;
my $debug;
my $update = 1;
my $log;
my $logfh;
if (!GetOptions("hosts|hostgroup=s" => \$hostgroup,
		"hostfile=s" => \$hostfile,