Simple IRC bot in Go.

README.md

Installation

$ mkdir Go && cd Go
$ mkdir -p {bin,pkg,src,src/pikabot,src/pikachu}
# Put content of pikachu.go in src/pikachu
# Put content of pikabot.go in src/pikabot and edit pikabot.go
$ go install pikabot
$ ./bin/pikabot

pikabot.go

package main

import (
	"fmt"
	"math/rand"
	"os"
	"os/signal"
	"pikachu"
	"strings"
	"time"
)

// https://en.wikiquote.org/wiki/Pok%C3%A9mon
// http://www.pokemonquotes.com/brock-quotes/
var QUOTES []string = []string{
	// Pikachu
	"“PIKA!” — Pikachu",
	"“Pika Pika” — Pikachu",
	"“Pika Pi” — Pikachu",
	"“Chuuuuu” — Pikachu",
	"“Pi-pi-pi” — Pikachu",
	"“PIKA-CHU-UUUUUUU!” — Pikachu",
	"“Pi Pikachu!” — Pikachu",

	// Brock
	"“Hey I know! I'll use my trusty frying pan as a drying pan!” — Brock",
	"“How about some prune juice!?” — Brock",
	"“I believe in rock-hard defense and determination!” — Brock",
	"“Her temper could sure use a little evolution.” — Brock",
	"“Don't you worry, Totodile, I'm gonna teach you how to be successful in love, just like me!” — Brock",
	"“When you have lemons, you make lemonade; and when you have rice, you make rice balls.” — Brock",
	"“For me, summer means bathing suits and girls to wear them!” — Brock",
	"“DON'T YOU GET IT?!! If two Butterfree fall in love, their trainers can meet, and THEY CAN FALL IN LOVE, TOO!” — Brock",
	"“AHH! I wasted a donut!” — Brock",
	"“Ash and Misty, sittin' in a tree... Ha ha ha ha ha!” — Brock",
	"“Time to dry up, water girl!” — Brock",
	"“I never forget the face of a pretty girl! This book helps me remember their names.” — Brock",
	"“This is the only song I know.” — Brock",

	// Misty
	"“If I want your opinion I'LL ASK FOR IT!!!” — Misty",
	"“HE'S NOT MY BOYFRIEND!” — Misty",
	"“Well, Ash Ketchum... finally, I know how you feel about me.” — Misty",
	"“Pikachu, you're a Pika-pal!” — Misty",
	"“Well, my name.....My name is Anne Chovie.” — Misty",

	// Ash Ketchum
	"“Choose it or lose it!” — Ash Ketchum",
	"“I'm twice as good as Gary!” — Ash Ketchum",
	"“It was an egg-cident! Get it? 'Egg?'” — Ash Ketchum",
	"“I have my own method of bending spoons. (bends the spoon with his hands) Ha! Muscle over mind!” — Ash Ketchum",
	"“Please don't eat my hat.” — Ash Ketchum",
	"“I'm having a major hat crisis. Could you try to steal Pikachu some other time?” — Ash Ketchum",
	"“Uh, my... name... is... Ketchup! No, wait! My name is really Tom Ato!” — Ash Ketchum",
	"“Let's eat fast so we can eat again!” — Ash Ketchum",
	"“That mini-Misty is even more scary than she is.” — Ash Ketchum",
	"“You look like a guy anyway!” — Ash Ketchum",
	"“Please don't stare at me like that! I'm a very shy little girl!” — Ash Ketchum",
	"“You guys go, I'll be fine. Just don't bring my mom home too late.” — Ash Ketchum",
	"“Yo, Brocko!” — Ash Ketchum",
	"“I choose you pikachu!” — Ash Ketchum",

	// Prof. Oak
	"“So, tell me about yourself. Are you a boy or a girl?” — Prof. Oak",
	"“This is my grandson. He's been your rival since you were both babies. Err... what was his name again...?” — Prof. Oak",
	"“You look more like you're ready for bed than Pokémon training.” — Prof. Oak",
	"“There's an ongoing debate in the academic community as to whether these Pidgey represent evolution, devolution, or some mutated strain.” — Prof. Oak",
}

func main() {
	rand.Seed(time.Now().UnixNano())
	l := len(QUOTES)

	// Setup IRC bot
	p, err := pikachu.Connect(
		"irc.zeronode.net:6667",
		"Pikachu",
		"Pikachu", "",
		"#Hive5")
	if err != nil {
		panic(err)
	}
	defer p.Close()

	// Graceful shutdown for Ctrl+C
	go func() {
		c := make(chan os.Signal, 1)
		signal.Notify(c, os.Interrupt)
		<-c

		p.Close()
		os.Exit(0)
	}()

	// Listen to receiving channel
	for {
		message, ok := <-p.Receive
		if ok == false {
			break
		}

		fmt.Println("IN: ", message)

		if message.Command == "PRIVMSG" && strings.HasPrefix(message.Final, "!pokemon") {
			p.Privmsg(message.Arguments[0], QUOTES[rand.Intn(l)])
		}
	}
}

pikachu.go

package pikachu

import (
	"bufio"
	"fmt"
	"net"
	"strings"
)

type Message struct {
	Prefix    string
	Command   string
	Arguments []string
	Final     string
}

type Pikachu struct {
	address    string
	nickname   string
	username   string
	password   string
	channel    string // Maybe list?
	connection net.Conn
	Send       chan string  // Messages to the server
	Receive    chan Message // Messages from the server
}

func Connect(address, nickname, username, password, channel string) (p *Pikachu, err error) {
	p = &Pikachu{address, nickname, username, password, channel, nil, nil, nil}
	err = p.Connect()
	return
}

func (p *Pikachu) Connect() (err error) {
	p.Send = make(chan string)
	p.Receive = make(chan Message)

	if p.connection, err = net.Dial("tcp", p.address); err != nil {
		return
	}

	go func() {
		var (
			message Message
			init    bool = true
		)
		reader := bufio.NewReader(p.connection)

		for {
			line, err := reader.ReadString('\n')
			if err != nil {
				break
			}

			message = p.ParseMessage(line)
			p.Receive <- message

			if message.Command == "PING" {
				p.Pong(message.Final)
			}

			if init {
				if message.Command == "266" {
					init = false
					p.Join(p.channel)
				}
			}
		}
	}()

	p.User(p.username, p.nickname)
	p.Nick(p.nickname)

	return
}

// [:prefix ](command )[arguments ]*[ :final_argument]
func (p *Pikachu) ParseMessage(line string) Message {
	var (
		prefix    string
		command   string
		arguments []string
		final     string
	)

	if pos := strings.Index(line, " :"); pos != -1 {
		arguments, final = strings.Split(line[:pos], " "), line[pos+2:len(line)-2]
	} else {
		arguments = strings.Split(line, " ")
	}

	if arguments[0][0] == ':' && len(arguments) >= 2 {
		prefix = arguments[0]
		command = arguments[1]
		arguments = arguments[2:]
	} else {
		command = arguments[0]
		arguments = arguments[1:]
	}

	return Message{prefix, command, arguments, final}
}

// server_or_nick[!user[@hostname]]
func (p *Pikachu) ParsePrefix(source string) (server_or_nick, user, host string) {
	if n := strings.IndexRune(source, '!'); n != -1 {
		server_or_nick = source[:n]
		if m := strings.IndexRune(source, '@'); m != -1 {
			user = source[n:m]
			host = source[m:]
		}
	} else {
		server_or_nick = source
	}

	return
}

func (p *Pikachu) Close() {
	p.connection.Close()
	close(p.Send)
	close(p.Receive)
}

func (p *Pikachu) Write(data string) {
	fmt.Println("OUT: ", data)
	if _, err := p.connection.Write([]byte(data + "\r\n")); err != nil {
		panic(err)
	}
}

func (p *Pikachu) User(username, realname string) {
	p.Write(fmt.Sprintf("USER %s +iw * :%s", username, realname))
}

func (p *Pikachu) Nick(nickname string) {
	p.Write(fmt.Sprintf("NICK %s", nickname))
}

func (p *Pikachu) Join(channel string) {
	p.Write(fmt.Sprintf("JOIN %s", channel))
}

func (p *Pikachu) Pong(payload string) {
	p.Write(fmt.Sprintf("PONG :%s", payload))
}

func (p *Pikachu) Privmsg(target, message string) {
	p.Write(fmt.Sprintf("PRIVMSG %s :%s", target, message))
}

func (p *Pikachu) Quit(message string) {
	p.Write(fmt.Sprintf("QUIT :%s", message))
}