Script to retrieve the users list in an IRC channel without running a bot. The “bot“ does not connects to the channels. Intended to be executed periodically. Does not works with secret (+s) channels. Python 2.7+.

irc.json

{"#chan": ["CheshireScrat", "Ichi", "Voren", "Anna", "GLaDOS", "Guy", "Swaps", "@Amaury", "Fanch"]}

irc_list.py

from __future__ import print_function

import socket
import random
import json


settings = {
        'network': 'irc.example.com',
        'port': 6667,
        'nick': 'Lst' + str(random.Random().randint(10000, 99999)),
        'channels': ['#chan']  # must be in mode -s
}


names = {}

irc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
irc.connect((settings['network'], settings['port']))

irc.send("USER "+ settings['nick'] +" "+ settings['nick'] +" "+ settings['nick'] +" :List bot\n") #user authentication
irc.send("NICK "+ settings['nick'] +"\n")

for chan in settings['channels']:
    irc.send("NAMES " + chan + "\n")

wait_for_names = True

while wait_for_names:
    text = irc.recv(2048)

    if text:
        lines = text.split("\r\n")
        for text in lines:
            if 'PING' in text:
                irc.send('PONG ' + text.split() [1] + '\r\n')
            elif ' 353 ' in text:  # code for names answer
                parts = text.strip().split(':')
                channel_names = parts[2].split(' ')
                channel = parts[1].strip().split(' ')[-1]
                
                if channel not in names:
                    names[channel] = channel_names
                else:
                    names[channel] += channel_names
                
            elif ' 366 ' in text:  # code for end of names answer
                parts = text.strip().split(':')
                channel = parts[1].strip().split(' ')[-1]
                
                # if received without names before then the channel is empty or
                # not accessible (+s).
                if channel not in names:
                    names[channel] = []
            
            if len(names) == len(settings['channels']):
                wait_for_names = False

with open('./irc.json', 'w') as f:
    print(json.dumps(names), file=f)