BUILDING_A_BOT.md

Building your first bot

Some basic things you should have covered before proceeding:

1. All of the necessary dependencies. The dependencies can be found at the Build Instructions.
2. A bot token. discord-irc has instructions on how to get one.
3. my_bot/ is your working directory, go into it to make your basic configuration:

cd my_bot
make config

Add your token to config.json by assigning it to discord's "token" field.

Here you have the option of editing myBot.c or start one from scratch.

Ping-Pong Bot Source Code

The entire code of ping-pong bot is below. We will go over it in further down:

#include <stdio.h>
#include <stdlib.h>

#include "discord.h"


void on_ready(struct discord *client)
{
  const struct discord_user *bot = discord_get_self(client);

  log_info("PingPong-Bot succesfully connected to Discord as %s#%s!",
      bot->username, bot->discriminator);
}

void on_ping(struct discord *client, const struct discord_message *msg)
{
  if (msg->author->bot) return; // ignore bots

  struct discord_create_message params = { .content = "pong" };
  discord_create_message(client, msg->channel_id, &params, NULL);
}

void on_pong(struct discord *client, const struct discord_message *msg)
{
  if (msg->author->bot) return; // ignore bots

  struct discord_create_message params = { .content = "ping" };
  discord_create_message(client, msg->channel_id, &params, NULL);
}

int main(void)
{
  struct discord *client = discord_config_init("../config.json");

  discord_set_on_ready(client, &on_ready);
  discord_set_on_command(client, "ping", &on_ping);
  discord_set_on_command(client, "pong", &on_pong);

  discord_run(client);

  discord_cleanup(client);

  return 0;
}

Initialize the bot

You can initialize the bot by providing a config.json file:

struct discord *client = discord_config_init("../config.json");

You can also initialize it by providing the token directly to discord_init():

struct discord *client = discord_init(BOT_TOKEN);

discord_config_init()

discord_config_init(char[]) : initialize the bot with a configuration file

Returns struct discord: the bot client

Member Parameters	Description
char[]	the name of the bot config file

discord_init()

discord_init(char[]) : initialize the bot with a token

Returns struct discord the bot client

Member Parameters	Description
char[]	the bot token string

Start the bot

discord_set_on_ready(client, &on_ready);
discord_set_on_command(client, "ping", &on_ping);
discord_set_on_command(client, "pong", &on_pong);

discord_run(client);

discord_set_on_ready()

discord_set_on_ready(struct discord*, discord_on_idle*): calls on_ready callback when the connection is succesfully established

Member Parameters	Description
struct discord	the client stucture
discord\_on\_idle()	the callback to run when the READY event is triggered

discord_set_on_command()

discord_set_on_command(struct discord*, char[], discord_message_cb*): runs callback when a command prefix is detected on chat

Member Parameters	Description
struct discord	the client stucture
char[]	The chat command expected to trigger a callback response
discord\_on\_message	the message type function callback to run when its corresponding event is triggered

discord_run()

discord_run(struct discord*): establishes a connection to Discord, run until error or shutdown

Member Parameters	Description
struct discord	the client stucture

Clean up the bot

discord_cleanup(client);

discord_cleanup()

discord_cleanup(struct discord*): cleanup client initialized by discord_init() or discord_config_init()

Compile the bot

make

Note: The preset Makefile will separately compile each file from the my_bot folder with .c extension.

Execute the bot

Simply run the generated executable like so:

./myBot

Test the bot

By heading to a channel your bot has access to and then type "ping" or "pong".

Terminate the bot

With Ctrl+c or by closing the Terminal.