Hack 58 A DiceBot

If you're an adventure gamer who likes to use IRC, make your own bot to roll the dice for you and your friends.

Dice are used for many games, such as yahtzee, craps, or even more elaborate adventure games like Warhammer (http://www.games-workshop.com). Some games even require special dice with more than six sides. If you lose your dice, you may become stuck where you are. But with an IRC bot to roll virtual dice for you, you'll always be able to play such games against other players on the Internet without any risk of anyone cheating, as you will be able to see their dice rolls.

This hack will show you how to make a simple IRC bot that rolls a single die with any number of sides.

9.2.1 The Code

The random numbers will be generated with an instance of the Random class in Java. This can be used to generate a pseudorandom sequence of numbers, which is more than adequate for a dice-rolling application.

The goal is to create a bot that responds to the !roll command by rolling a die and displaying the value.

Create a file called DiceBot.java:

import org.jibble.pircbot.*;

import java.util.Random;



public class DiceBot extends PircBot {

    

    private Random random = new Random( );

    

    public DiceBot(String name) {

        setName(name);

    }

    

    public void onMessage(String channel, String sender,

            String login, String hostname, String message) {

        

        message = message.trim( ).toLowerCase( );

        

        if (message.equals("!roll")) {

            sendMessage(channel, "I rolled a " + (random.nextInt(6) + 1));

        }

        else if (message.equals("!shoot")) {

            if (random.nextInt(6) == 0) {

                kick(channel, sender, "BANG!");

            }

            else {

                sendMessage(channel, sender + ": click");

            }

        }

    }



}

Notice that another feature has been introduced to the bot: a kind of Russian roulette game. If a user sends the message !shoot to the channel, there will be a one in six chance of the bot kicking him from the channel with the reason, "BANG!" If the user manages to escape the bullet, the bot will just send "click" to the channel.

For the Russian roulette feature to work properly, the bot must have channel operator status in the appropriate channels. The bot is capable of running in multiple channels.

A main method is required to tell the bot which server to connect to and which channel or channels to join. Save the following as DiceBotMain.java:

public class DiceBotMain {

    

    public static void main(String[] args) throws Exception {

        DiceBot bot = new DiceBot("Dice");

        bot.setVerbose(true);

        bot.connect("irc.freenode.net");

        bot.joinChannel("#irchacks");

    }

    

}

9.2.2 Running the Hack

You can compile the hack by typing:

C:\java\DiceBot> javac -classpath pircbot.jar;. *.java

Run the hack with:

C:\java\DiceBot> java -classpath pircbot.jar;. DiceBotMain

9.2.3 The Results

Figure 9-1 shows users Jibbler and Monty being lucky with their dice rolling. Jibbler then ends up getting kicked from the channel by pushing his luck with the !shoot command.

Figure 9-1. Using the DiceBot

Advanced gamers can easily modify this bot to roll dice with more than six sides. If you are feeling adventurous, you could even try to create a bot that takes part in these games.