Python 3 IRCbot (library)

Question

Just want you guys to review my python 3 IRC bot code, it is actually a fork of https://github.com/Orderchaos/LinuxAcademy-IRC-Bot

You can see the source code at github

I also have questions:

1. I really can't find out how to change the ident for the bot, can I change the ident?
2. Can I change the ident by modifying the user authentication code?

In addition to answering my question, you can submit a pr at GitHub if you want yourself to be in the contributions list.

The ircbot.py file is as below:

"""
Copyright (c) 2016 Linux Academy
Copyright (c) 2021 BK IRCbot team and contributors

Licensed under GNU Lesser General Public License v2.1
See the LICENSE file distributed with the source code
OR Visit https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html

This project is a fork of https://github.com/Orderchaos/LinuxAcademy-IRC-Bot

NOTE      This program is distributed in the hope that it will be useful - WITHOUT
           ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
           FITNESS FOR A PARTICULAR PURPOSE.
"""

# socket for irc socket
import socket
# os for file handling, currently not required
# import os

# conf
from conf import server, port, channel, botnick, adminnick, password, exitcode, filename

# Create a socket
ircsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

if adminnick == "" or botnick == "":
    print("Notice: BK_IRCbot: adminnick or botnick is empty!")

ircsock.connect((server, port))  # Here we connect to the server
# We need to send some info to the server to let the server identify us.
# USER <username> <hostname> <servername> :<realname>
ircsock.send(bytes(
    "USER " + botnick + " " + botnick + " " + botnick +
    " :IRCbot by Linux Academy and Puneet Gopinath.\n",
    "UTF-8"
))  # user information
ircsock.send(bytes(
    "NICK " + botnick + "\n",
    "UTF-8"
))  # assign the nick to the bot
ircsock.send(bytes(
    "NickServ identify " + password + "\n",
    "UTF-8"
))  # login to the botnick's IRC account


def joinchan(chan):
    """Join channel(s)

    Parameters:
    chan (string): Channel(s) to join. Seperate a channel using a comma, e.g. #chan,#chan2

    Returns:
    null: Returns null.
    """
    # The ‘bytes’ part and "UTF-8” says to send the message to IRC as UTF-8 encoded bytes.
    # You will see this on all the lines where we send data to the IRC server.
    ircsock.send(bytes("JOIN " + chan + "\n", "UTF-8"))
    # The "\n” at the end of the line denotes to send a new line character.
    # It tells the server that we’re finished that command.
    # After sending the join command, we start a loop
    # To continuously check and receive new info from server
    # UNTIL we get a message from the server ‘End of /NAMES list.’.
    # This will indicate we have successfully joined the channel.
    # The details of how each function works is described in the main function section below.
    # This is necessary so we don't process the joining message as commands.
    ircmsg = ""
    while ircmsg.find("End of /NAMES list.") == -1:
        ircmsg = ircsock.recv(2048).decode("UTF-8")
        ircmsg = ircmsg.strip("\n\r")
        print(ircmsg)


def ping():
    """If the server send a ping to us, respond with a pong.

    Returns:
    null: Returns null.
    """
    ircsock.send(bytes("PONG :pingis\n", "UTF-8"))


def sendmsg(msg, target):
    """Send a message to a channel or some nick

    Parameters:
    msg (string): The message.
    target (string): Send message to which channel/nick?

    Returns:
    null: Returns null.
    """
    # Here we are sending a PRIVMSG to the server.
    # The " :" lets the server separate the target and the message.
    ircsock.send(bytes("PRIVMSG " + target + " :" + msg + "\n", "UTF-8"))


def logger(name, msg):
    """Log message

    Parameters:
    name (string): Name to person who sent the message
    msg (string): The message.

    Returns:
    null: Returns null.
    """
    irclog = open(filename, "r")
    content = irclog.readlines()
    irclog.close()
    # loop through the content of the chat log and reduce to 100 lines, starting with oldest.
    # Definitely a better way to do this, needs improvement.
    irclog = open(filename, "w")
    while len(content) > 100:
        content.remove(content[0])
    if len(content) > 0:
        for i in content:
            irclog.write(i.strip("\n\r") + "\n")
    # write newest message to log.
    irclog.write(name + ":" + msg.strip("\n\r") + "\n")
    irclog.close()


def start():
    """Start the bot

    Returns:
    null: Returns null.
    """
    # start by joining the channel(s) we defined.
    chan = ""
    for x in channel:
        chan += x + ","
    joinchan(chan)
    # Start infinite loop to keep checking and receive new info from server.
    # This ensures our connection stays open.
    # An infinite while loop works better in this case.
    while 1:
        # Here we are receiving information from the IRC server.
        # IRC will send out information encoded in UTF-8 characters
        # We’re telling our socket to receive up to 2048 bytes and decode it as UTF-8 characters.
        # We then assign it to the ircmsg variable for processing.
        ircmsg = ircsock.recv(2048).decode("UTF-8")
        # This part will remove any line break characters from the string.
        ircmsg = ircmsg.strip("\n\r")
        # This will print the received information to your terminal.
        # Useful for debugging purposes
        print(ircmsg)
        # Here we check if the information we received was a PRIVMSG.
        # PRIVMSG is standard messages sent to the channel or direct messages sent to the bot.
        # Most of the processing of messages will be in this section.
        if ircmsg.find("PRIVMSG") != -1:
            # Messages come from IRC in the format of
            # ":[Nick]!~[hostname]@[IP Address] PRIVMSG [channel] :[message]"
            name = ircmsg.split("!", 1)[0][1:]
            # message.
            message = ircmsg.split("PRIVMSG", 1)[1].split(" :", 1)[1]
            # To whom (or to which channel) it was sent.
            sentTo = ircmsg.split("PRIVMSG", 1)[1].split(" :", 1)[0].lstrip()
            if (sentTo.lower() == botnick.lower()):
                sendTo = name
            else:
                sendTo = sendTo
            # Log the message
            logger(name, "(Sent To: " + sentTo + ") :" + message)
            # We check if the name is less than 17 characters.
            # Nicks (at least for Freenode) are limited to 16 characters.
            admin = name.lower() == adminnick.lower()
            if len(name) < 17:
                if message.find("Hi " + botnick) != -1 or message.find("Who is " + botnick) != -1:
                    sendmsg("Hello " + name + "!", sendTo)
                    sendmsg(
                        "I am a bot created by PuneetGopinath, " +
                        "initialy developed by Linux Academy. " +
                        "Credits to Linux Academy and PuneetGopinath. " +
                        "Please report any issues at " +
                        "https://github.com/PuneetGopinath/IRCbot/issues",
                        sendTo
                    )
                if admin and message.rstrip() == "Clear the file, " + botnick:
                    sendmsg("Ok, will clear the file.", sendTo)
                    irclog = open(filename, "w")
                    irclog.write("")
                    irclog.close()
                # Here we add in some code to help us get the bot to stop.
                # Check whether the name of the person sending the message matches the admin nick.
                # We make sure the message EXACTLY matches the exit code above.
                # The only adjustment here is to trim at the right end of the message.
                if admin and message.rstrip() == exitcode:
                    sendmsg(
                        "Bye... 😭 Waiting to see you again!!",
                        sendTo
                    )
                    # Send the quit command to the IRC server so it knows we’re leaving.
                    ircsock.send(bytes("QUIT \n", "UTF-8"))
                    # The return command ends the function here
                    # So the bot stops
                    return
        # If the message is not a PRIVMSG it still might need some response.
        else:
            # Check if the info we received was a PING request.
            # If yes, we call the ping() function so we respond with a PONG to the server.
            if ircmsg.find("PING :") != -1:
                ping()


# The main function is defined, we need to start it.
start()

And the conf.py:

"""
Copyright (c) 2021 BK IRCbot team and contributors

Licensed under GNU Lesser General Public License v2.1
See the LICENSE file distributed with the source code
OR Visit https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html

This project is a fork of https://github.com/Orderchaos/LinuxAcademy-IRC-Bot

NOTE      This program is distributed in the hope that it will be useful - WITHOUT
           ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
           FITNESS FOR A PARTICULAR PURPOSE.
"""

server = "chat.freenode.net"  # Server to connect.
port = 6667  # Port to use when connecting
channel = ["#chan"]  # Array of channels to join.
botnick = ""  # Your bot's nickname.
adminnick = ""  # Your IRC nickname.
password = ""  # Your IRC bot's password.
exitcode = "Stop " + botnick  # The message we will use to stop the bot if sent by admin.
filename = "ircchat.log"  # Filename in which messages will be logged.

Answer 1

This program - and the program it's forked from - have somewhat severe issues. You may want to be more judicious in the repositories you're using to learn.

ircsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

needs to be protected with a context management with to guarantee closure, and should not be done at global scope. Similar for irclog.

if adminnick == "" or botnick == "":
    print("Notice: BK_IRCbot: adminnick or botnick is empty!")

seems like something that should hard-raise instead of printing and attempting to continue with execution.

Your pattern of

bytes(
    "USER " + botnick + " " + botnick + " " + botnick +
    " :IRCbot by Linux Academy and Puneet Gopinath.\n",
    "UTF-8"
)

is a more awkward way of saying

(
    f'USER {botnick} {botnick} {botnick} '
    f':IRCbot by Linux Academy and Puneet Gopinath.\n'
).encode('UTF-8')

This client is deeply insecure; it transmits your password in plaintext over the wire. Read e.g. https://freenode.net/kb/answer/sasl for more information.

joinchan (which would be better named join_channel) would be better off accepting an iterable of strings, and doing ','.join on them before sending it off to the server.

This loop:

    ircmsg = ""
    while ircmsg.find("End of /NAMES list.") == -1:
        ircmsg = ircsock.recv(2048).decode("UTF-8")
        ircmsg = ircmsg.strip("\n\r")
        print(ircmsg)

betrays a classic misunderstanding of the way that TCP/IP works that beginners nearly universally stub their toe on. Packets get fragmented. Asking to receive up to 2kB does NOT guarantee:

• that you've received a complete message; or even
• that the message is not fragmented across packet boundaries.

In other words, there's nothing stopping any of the routers between you and the server from sending

End of /N

in one packet and

AMES list.

in the second. For you to gain those guarantees of non-fragmentation you either need to do your own buffering or call into a Python networking abstraction layer that will do it for you.

conf.py is not a great place to store configuration in. Consider making an actual configuration file instead.

This:

content = irclog.readlines()
while len(content) > 100:
    content.remove(content[0])

is not efficient, and should be replaced with a single slice operation, probably

content = irclog.readlines()[:-100]