source: npl/mediabox/lcdproc_edwin/src/clients/examples/iosock.pl

#!/usr/local/bin/perl -w

use IO::Socket;
use Fcntl;

# Connect to the server...
$remote = IO::Socket::INET->new(
                Proto     => "tcp",
                PeerAddr  => "localhost",
                PeerPort  => "13666",
        )
        || die "Cannot connect to LCDproc port\n";

# Make sure our messages get there right away
$remote->autoflush(1);

`sleep 1`;      # Give server plenty of time to notice us...

print $remote "hello\n";
my $lcdconnect = <$remote>;
print $lcdconnect;


# Turn off blocking mode...
fcntl($remote, F_SETFL, O_NONBLOCK);


# Set up some screen widgets...
print $remote "client_set name {Test Client (Perl)}\n";
print $remote "screen_add pings\n";
print $remote "screen_set pings name {Ping Status}\n";
print $remote "widget_add pings title title\n";
print $remote "widget_set pings title {Ping Status}\n";
print $remote "widget_add pings one string\n";
print $remote "widget_add pings two string\n";
print $remote "widget_set pings one 1 2 {Checking machines...}\n";


my ($machine, %down, %up, $i, $list);

while(1)
{
        #print "Main loop...\n";
        # Handle input...  (just spew it to the console)
        while(defined($line = <$remote>)) {
            print $line;
        }

        undef %down;
        undef %up;
        foreach $machine       ("www.yahoo.com", 
                                "webfoot",
                                "degas", 
                                "cassat", 
                                "miro", 
                                "monet",
                                "dali",
                                "escher",
                                "seurat",
                                "rodin",
                                "matisse",
                                )
        {
                `ping -c 1 $machine`;
                if($?) { $down{$machine} = 1; }
                else { $up{$machine} = 1; }
        }
        $i = 0;  $list = "";
        foreach $machine (keys %up)
        {
                $i++;
                $list .= "$machine, ";
        }
        print $remote "widget_set pings one 1 2 {Machines Up: $i}\n";
        $i = 0;  $list = "";
        foreach $machine (keys %down)
        {
                $i++;
                $list .= "$machine, ";
        }
        print $remote "widget_set pings two 1 3 {Down ($i): $list}\n";
}

close ($remote)            || die "close: $!";
exit;