foo.pl6

#!/usr/bin/env perl6

role Monitor {
    method events returns Channel { ... }
    method start { ... }
    method stop { ... }
}

class PingMonitor does Monitor {
    has Channel $.events;
    has Proc::Async $!proc;
    has @!argv;

    method new(Str $host, Duration $interval, Duration $timeout) {
        my @argv = "-i", $interval.Int, "-W", $timeout.Int, $host;
        self.bless(:@argv);
    }

    submethod BUILD(:@!argv) {
        $!events = Channel.new;
    }

    method start {
        $!proc = Proc::Async.new("ping", @!argv);
        $!proc.stdout.act: {
            my $milliseconds = $_ ~~ /time\=((\d|\.)+)/ && $0;
            $!events.send(Duration.new($milliseconds / 1000));
        };
        $!proc.start;
    }

    method stop {
        $!proc.kill;
    }
}

my $mon = PingMonitor.new("localhost", Duration.new(1), Duration.new(1));
$mon.start;
for (1..10) {
    say $mon.events.receive;
}
$mon.stop;