open (my $fd, "<", $conf->{pidfile})
        or die "Failed to read pidfile $conf->{pidfile}: $!";

    my $pid = <$fd>;
    chomp $pid;
    die "Broken pid file $conf->{pidfile}"
        unless $pid =~ /^\d+$/;

    # detect stale pid
    if ([stat $fd]->[9] >= ([stat "/proc/$pid"]->[9] || 9**9**9)) {
        print "Killing pid $pid...\n";
        kill INT => $pid;
    };