perlbal-top

use strict;
use warnings;
use IO::Socket::INET;
use Getopt::Long;

my $cmd = join q{ }, @ARGV;
my $port = 60000;
my $host = '127.0.0.1';
my $timeout = 10;

GetOptions(
    'port=i'    => \$port,
    'host=s'    => \$host,
    'timeout=i' => \$timeout,
);

my $interval_sec = 3;

my $ip_of = {};
while (1) {
    print "\033[2J"; # flush screen
    my $sock = IO::Socket::INET->new(
        PeerAddr => $host,
        PeerPort => $port,
        Timeout  => $timeout,
    ) or die "cannot connect to $host:$port";
    $sock->autoflush(1);

    $sock->write($cmd . "\r\nquit\r\n");

    my $out = '';
    while ( my $line = <$sock> ) {
        if ( $line =~ /(\d+\.\d+\.\d+\.\d+):\d+\s+(\d+)/ ) {
            my $ip = $1;
            my $count = $2;
            $ip_of->{$ip} ||= [0,0];
            chomp $line;
            $line = "$line (+ @{[ $count - ( $ip_of->{$ip}->[0] || 0 ) ]})\n";
            pop @{$ip_of->{$ip}};
            unshift @{$ip_of->{$ip}}, $count;
        }
        $out .= $line;
    }
    my $sum = 0;
    my $num_of_server = 0;
    for my $ip ( keys %{ $ip_of } ) {
        $sum += ( $ip_of->{$ip}->[0] - $ip_of->{$ip}->[1] );
        $num_of_server++;
    }
    $out .= sprintf("avg: %.2f\n", $sum / $num_of_server);

    print $out;

    $sock->close;

    sleep($interval_sec);
}