#CordCGI

Do one thing, and one thing terrible.

I took the worst parts of WebCGI and turned it into a web framework:

Make a directory cgi-bin, add a bunch of programs to that. At the moment, the only meaningful thing you can do with this is reply to messages. But that's OK! Write your hello world in bash:

$ cat > cgi-bin/hello <<EOF
#!/bin/sh
echo "<@${DISCORD_MESSAGE_AUTHOR}> Hello, World!"
EOF
$ chmod +X cgi-bin/hello

Or maybe you like Python:

#!/usr/bin/env python3
import os

user = os.environ['DISCORD_MESSAGE_AUTHOR']
print(f"<@{user}> Hello, World!")

Perl? Why not!

#!/usr/bin/perl
use Env qw(DISCORD_MESSAGE_AUTHOR);

print "<\@$DISCORD_MESSAGE_AUTHOR> Hello, World!";

Go crazy. Go stupid!!!

#!/usr/bin/tcc -run
#include<stdio.h>
#include<stdlib.h>

int
main(void)
{
	printf("<@%s> Hello, World!\n", getenv("DISCORD_MESSAGE_AUTHOR"));
	return 0;
}

This is really a bad way to write software.

#Setup

Copy settings.json.example to settings.json. Write your client ID, bot token, and preferred command prefix. Set CgiBin to the path to the directory that calls your code. I recommend setting it to ./example-cgi-bin and trying out all the commands there. Relative paths are relative to the working directory when you run the program.

go get github.com/bwmarrin/discordgo, go run . and bam! Discord bot!

Your CgiBin directory (which I'm assuming is cgi-bin/ for now) would be a collection of programs -- scripts, binary executables, anything -- that would be run for each command. If someone, for example, says !add 10 20 (assuming the prefix is !), and there is an executable in cgi-bin called add, it is run with the argv arguments 10 and 20. One interesting thing to note is that subdirectories kind-of work as subcommands. The command !directory/command is a valid pathname, and if cgi/directory/command exists, that would be executed.

When a program is run, it will be provided the entire message's content into stdin, it is provided message data as environment varaibles, and it will take all stdout as a reply. The environment varables are:

• DISCORD_MESSAGE - the message's ID
• DISCORD_MESSAGE_AUTHOR - the message's author's ID
• DISCORD_MESSAGE_AUTHOR_AVATAR - the author's avatar ID
• DISCORD_MESSAGE_AUTHOR_LOCALE - the author's preferred locale
• DISCORD_MESSAGE_AUTHOR_USERNAME - the author's username
• DISCORD_MESSAGE_CHANNEL - the message's channel's ID
• DISCORD_MESSAGE_GUILD - the message's guild's ID
• DISCORD_MESSAGE_UNIXNANOS - the timestamp of the message, as the nanoseconds since Unix epoch.

#Reflection

In retrospect, if the only discord things you need to do is read the message calling commands and reply to them, this would probably be a really good way to prototype it. Once your bot needs to become any more rich, though, this probably falls apart. Overall, I recommend against using this for serious bot development unless you're doing it for laughs.