Come up with sillier names for the binaries

I'm not entirely sure, but it looks like some people might not like
jokes about the Holocaust.

On a more serious note, the project has become more serious over
the 7 or so years of its existence.

9 files changed, 757 insertions, 0 deletions

diff --git a/plugins/xC/auto-rejoin.lua b/plugins/xC/auto-rejoin.lua
new file mode 100644
index 0000000..f42fb2e
--- /dev/null
+++ b/plugins/xC/auto-rejoin.lua
@@ -0,0 +1,48 @@
+--
+-- auto-rejoin.lua: join back automatically when someone kicks you
+--
+-- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+local timeout
+xC.setup_config {
+	timeout = {
+		type = "integer",
+		comment = "auto rejoin timeout",
+		default = "0",
+
+		on_change = function (v)
+			timeout = v
+		end,
+		validate = function (v)
+			if v < 0 then error ("timeout must not be negative", 0) end
+		end,
+	},
+}
+
+async, await = xC.async, coroutine.yield
+xC.hook_irc (function (hook, server, line)
+	local msg = xC.parse (line)
+	if msg.command ~= "KICK" then return line end
+
+	local who = msg.prefix:match ("^[^!]*")
+	local channel, whom = table.unpack (msg.params)
+	if who ~= whom and whom == server.user.nickname then
+		async.go (function ()
+			await (async.timer_ms (timeout * 1000))
+			server:send ("JOIN " .. channel)
+		end)
+	end
+	return line
+end)
diff --git a/plugins/xC/censor.lua b/plugins/xC/censor.lua
new file mode 100644
index 0000000..49cab5b
--- /dev/null
+++ b/plugins/xC/censor.lua
@@ -0,0 +1,90 @@
+--
+-- censor.lua: black out certain users' messages
+--
+-- Copyright (c) 2016 - 2021, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+local to_pattern = function (mask)
+	if not mask:match ("!") then mask = mask .. "!*" end
+	if not mask:match ("@") then mask = mask .. "@*" end
+
+	-- That is, * acts like a wildcard, otherwise everything is escaped
+	return "^" .. mask:gsub ("[%^%$%(%)%%%.%[%]%+%-%?]", "%%%0")
+		:gsub ("%*", ".*") .. "$"
+end
+
+local patterns = {}
+local read_masks = function (v)
+	patterns = {}
+	local add = function (who, where)
+		local channels = patterns[who] or {}
+		table.insert (channels, where)
+		patterns[who] = channels
+	end
+	for item in v:lower ():gmatch ("[^,]+") do
+		local who, where = item:match ("^([^/]+)/*(.*)")
+		if who then add (to_pattern (who), where == "" or where) end
+	end
+end
+
+local quote
+xC.setup_config {
+	masks = {
+		type = "string_array",
+		default = "\"\"",
+		comment = "user masks (optionally \"/#channel\") to censor",
+		on_change = read_masks
+	},
+	quote = {
+		type = "string",
+		default = "\"\\x0301,01\"",
+		comment = "formatting prefix for censored messages",
+		on_change = function (v) quote = v end
+	},
+}
+
+local decolor = function (text)
+	local rebuilt, last = {""}, 1
+	for start in text:gmatch ('()\x03') do
+		table.insert (rebuilt, text:sub (last, start - 1))
+		local sub = text:sub (start + 1)
+		last = start + (sub:match ('^%d%d?,%d%d?()') or sub:match ('^%d?%d?()'))
+	end
+	return table.concat (rebuilt) .. text:sub (last)
+end
+
+local censor = function (line)
+	-- Taking a shortcut to avoid lengthy message reassembly
+	local start, text = line:match ("^(.- PRIVMSG .- :)(.*)$")
+	local ctcp, rest = text:match ("^(\x01%g+ )(.*)")
+	text = ctcp and ctcp .. quote .. decolor (rest) or quote .. decolor (text)
+	return start .. text
+end
+
+xC.hook_irc (function (hook, server, line)
+	local msg = xC.parse (line)
+	if msg.command ~= "PRIVMSG" then return line end
+
+	local channel = msg.params[1]:lower ()
+	for who, where in pairs (patterns) do
+		if msg.prefix:lower ():match (who) then
+			for _, x in pairs (where) do
+				if x == true or x == channel then
+					return censor (line)
+				end
+			end
+		end
+	end
+	return line
+end)
diff --git a/plugins/xC/fancy-prompt.lua b/plugins/xC/fancy-prompt.lua
new file mode 100644
index 0000000..8ec697a
--- /dev/null
+++ b/plugins/xC/fancy-prompt.lua
@@ -0,0 +1,105 @@
+--
+-- fancy-prompt.lua: the fancy multiline prompt you probably want
+--
+-- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+-- Beware that it is a hack and only goes about 90% of the way, which is why
+-- this functionality is only available as a plugin in the first place
+-- (well, and also for customizability).
+--
+-- The biggest problem is that the way we work with Readline is incompatible
+-- with multiline prompts, and normal newlines just don't work.  This is being
+-- circumvented by using an overflowing single-line prompt with a specially
+-- crafted character in the rightmost column that prevents the bar's background
+-- from spilling all over the last line.
+--
+-- There is also a problem with C-r search rendering not clearing out the
+-- background but to really fix that mode, we'd have to fully reimplement it
+-- since its alternative prompt very often gets overriden by accident anyway.
+
+xC.hook_prompt (function (hook)
+	local current = xC.current_buffer
+	local chan = current.channel
+	local s = current.server
+
+	local bg_color = "255"
+	local current_n = 0
+	local active = ""
+	for i, buffer in ipairs (xC.buffers) do
+		if buffer == current then
+			current_n = i
+		elseif buffer.new_messages_count ~= buffer.new_unimportant_count then
+			if active ~= "" then active = active .. "," end
+			if buffer.highlighted then
+				active = active .. "!"
+				bg_color = "224"
+			end
+			active = active .. i
+		end
+	end
+	if active ~= "" then active = "(" .. active .. ")" end
+	local x = current_n .. ":" .. current.name
+	if chan and chan.users_len ~= 0 then
+		local params = ""
+		for mode, param in pairs (chan.param_modes) do
+			params = params .. " +" .. mode .. " " .. param
+		end
+		local modes = chan.no_param_modes .. params:sub (3)
+		if modes ~= "" then x = x .. "(+" .. modes .. ")" end
+		x = x .. "{" .. chan.users_len .. "}"
+	end
+	if current.hide_unimportant then x = x .. "<H>" end
+
+	local lines, cols = xC.get_screen_size ()
+	x = x .. " " .. active .. string.rep (" ", cols)
+
+	-- Readline 7.0.003 seems to be broken and completely corrupts the prompt.
+	-- However 8.0.004 seems to be fine with these, as is libedit 20191231-3.1.
+	--x = x:gsub("[\128-\255]", "?")
+
+	-- Cut off extra characters and apply formatting, including the hack.
+	-- FIXME: this doesn't count with full-width or zero-width characters.
+	--   We might want to export wcwidth() above term_from_utf8 somehow.
+	local overflow = utf8.offset (x, cols - 1)
+	if overflow then x = x:sub (1, overflow) end
+	x = "\x01\x1b[0;4;1;38;5;16m\x1b[48;5;" .. bg_color .. "m\x02" ..
+		x ..  "\x01\x1b[0;4;1;7;38;5;" .. bg_color .. "m\x02 \x01\x1b[0;1m\x02"
+
+	local user_prefix = function (chan, user)
+		for i, chan_user in ipairs (chan.users) do
+			if chan_user.user == user then return chan_user.prefixes end
+		end
+		return ""
+	end
+	if s then
+		x = x .. "["
+		local state = s.state
+		if state == "disconnected" or state == "connecting" then
+			x = x .. "(" .. state .. ")"
+		elseif state ~= "registered" then
+			x = x .. "(unregistered)"
+		else
+			local user, modes = s.user, s.user_mode
+			if chan then x = x .. user_prefix (chan, user) end
+			x = x .. user.nickname
+			if modes ~= "" then x = x .. "(" .. modes .. ")" end
+		end
+		x = x .. "] "
+	else
+		-- There needs to be at least one character so that the cursor
+		-- doesn't get damaged by our hack in that last column
+		x = x .. "> "
+	end
+	return x
+end)
diff --git a/plugins/xC/last-fm.lua b/plugins/xC/last-fm.lua
new file mode 100644
index 0000000..3bdfed2
--- /dev/null
+++ b/plugins/xC/last-fm.lua
@@ -0,0 +1,178 @@
+--
+-- last-fm.lua: "now playing" feature using the last.fm API
+--
+-- Dependencies: lua-cjson (from luarocks e.g.)
+--
+-- I call this style closure-oriented programming
+--
+-- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+local cjson = require "cjson"
+
+-- Setup configuration to load last.fm API credentials from
+local user, api_key
+xC.setup_config {
+	user    = {
+		type = "string",
+		comment = "last.fm username",
+		on_change = function (v) user    = v end
+	},
+	api_key = {
+		type = "string",
+		comment = "last.fm API key",
+		on_change = function (v) api_key = v end
+	},
+}
+
+-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+-- Generic error reporting
+local report_error = function (buffer, error)
+	buffer:log ("last-fm error: " .. error)
+end
+
+-- Process data return by the server and extract the now playing song
+local process = function (buffer, data, action)
+	-- There's no reasonable Lua package to parse HTTP that I could find
+	local s, e, v, status, message = string.find (data, "(%S+) (%S+) .+\r\n")
+	if not s then return "server returned unexpected data" end
+	if status ~= "200" then return status .. " " .. message end
+
+	local s, e = string.find (data, "\r\n\r\n")
+	if not s then return "server returned unexpected data" end
+
+	local parser = cjson.new ()
+	data = parser.decode (string.sub (data, e + 1))
+	if not data.recenttracks or not data.recenttracks.track then
+		return "invalid response" end
+
+	-- Need to make some sense of the XML automatically converted to JSON
+	local text_of = function (node)
+		if type (node) ~= "table" then return node end
+		return node["#text"] ~= "" and node["#text"] or nil
+	end
+
+	local name, artist, album
+	for i, track in ipairs (data.recenttracks.track) do
+		if track["@attr"] and track["@attr"].nowplaying then
+			if track.name   then name   = text_of (track.name)   end
+			if track.artist then artist = text_of (track.artist) end
+			if track.album  then album  = text_of (track.album)  end
+		end
+	end
+
+	if not name then
+		action (false)
+	else
+		local np = "\"" .. name .. "\""
+		if artist then np = np .. " by "   .. artist end
+		if album  then np = np .. " from " .. album  end
+		action (np)
+	end
+end
+
+-- Set up the connection and make the request
+local on_connected = function (buffer, c, host, action)
+	-- Buffer data in the connection object
+	c.data = ""
+	c.on_data = function (data)
+		c.data = c.data .. data
+	end
+
+	-- And process it after we receive everything
+	c.on_eof = function ()
+		error = process (buffer, c.data, action)
+		if error then report_error (buffer, error) end
+		c:close ()
+	end
+	c.on_error = function (e)
+		report_error (buffer, e)
+	end
+
+	-- Make the unencrypted HTTP request
+	local url = "/2.0/?method=user.getrecenttracks&user=" .. user ..
+		"&limit=1&api_key=" .. api_key .. "&format=json"
+	c:send ("GET " .. url .. " HTTP/1.1\r\n")
+	c:send ("User-agent: last-fm.lua\r\n")
+	c:send ("Host: " .. host .. "\r\n")
+	c:send ("Connection: close\r\n")
+	c:send ("\r\n")
+end
+
+-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+-- Avoid establishing more than one connection at a time
+local running
+
+-- Initiate a connection to last.fm servers
+async, await = xC.async, coroutine.yield
+local make_request = function (buffer, action)
+	if not user or not api_key then
+		report_error (buffer, "configuration is incomplete")
+		return
+	end
+
+	if running then running:cancel () end
+	running = async.go (function ()
+		local c, host, e = await (async.dial ("ws.audioscrobbler.com", 80))
+		if e then
+			report_error (buffer, e)
+		else
+			on_connected (buffer, c, host, action)
+		end
+		running = nil
+	end)
+end
+
+-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+local now_playing
+
+local tell_song = function (buffer)
+	if now_playing == nil then
+		buffer:log ("last-fm: I don't know what you're listening to")
+	elseif not now_playing then
+		buffer:log ("last-fm: not playing anything right now")
+	else
+		buffer:log ("last-fm: now playing: " .. now_playing)
+	end
+end
+
+local send_song = function (buffer)
+	if not now_playing then
+		tell_song (buffer)
+	else
+		buffer:execute ("/me is listening to " .. now_playing)
+	end
+end
+
+-- Hook input to simulate new commands
+xC.hook_input (function (hook, buffer, input)
+	if input == "/np" then
+		make_request (buffer, function (np)
+			now_playing = np
+			send_song (buffer)
+		end)
+	elseif input == "/np?" then
+		make_request (buffer, function (np)
+			now_playing = np
+			tell_song (buffer)
+		end)
+	elseif input == "/np!" then
+		send_song (buffer)
+	else
+		return input
+	end
+end)
diff --git a/plugins/xC/ping-timeout.lua b/plugins/xC/ping-timeout.lua
new file mode 100644
index 0000000..c455c57
--- /dev/null
+++ b/plugins/xC/ping-timeout.lua
@@ -0,0 +1,32 @@
+--
+-- ping-timeout.lua: ping timeout readability enhancement plugin
+--
+-- Copyright (c) 2015 - 2016, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+xC.hook_irc (function (hook, server, line)
+	local msg = xC.parse (line)
+	local start, timeout = line:match ("^(.* :Ping timeout:) (%d+) seconds$")
+	if msg.command ~= "QUIT" or not start then
+		return line
+	end
+
+	local minutes = timeout // 60
+	if minutes == 0 then
+		return line
+	end
+
+	local seconds = timeout % 60
+	return ("%s %d minutes, %d seconds"):format (start, minutes, seconds)
+end)
diff --git a/plugins/xC/prime.lua b/plugins/xC/prime.lua
new file mode 100644
index 0000000..23740ee
--- /dev/null
+++ b/plugins/xC/prime.lua
@@ -0,0 +1,68 @@
+--
+-- prime.lua: highlight prime numbers in messages
+--
+-- Copyright (c) 2020, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+local smallest, highlight = 0, "\x1f"
+xC.setup_config {
+	smallest = {
+		type = "integer",
+		default = "0",
+		comment = "smallest number to scan for primality",
+		on_change = function (v) smallest = math.max (v, 2) end
+	},
+	highlight = {
+		type = "string",
+		default = "\"\\x1f\"",
+		comment = "the attribute to use for highlights",
+		on_change = function (v) highlight = v end
+	},
+}
+
+-- The prime test is actually very fast, so there is no DoS concern
+local do_intercolour = function (text)
+	return tostring (text:gsub ("%f[%w_]%d+", function (n)
+		if tonumber (n) < smallest then return nil end
+		for i = 2, n ^ (1 / 2) do if (n % i) == 0 then return nil end end
+		return highlight .. n .. highlight
+	end))
+end
+
+local do_interlink = function (text)
+	local rebuilt, last = {""}, 1
+	for start in text:gmatch ('()\x03') do
+		table.insert (rebuilt, do_intercolour (text:sub (last, start - 1)))
+		local sub = text:sub (start + 1)
+		last = start + (sub:match ('^%d%d?,%d%d?()') or sub:match ('^%d?%d?()'))
+		table.insert (rebuilt, text:sub (start, last - 1))
+	end
+	return table.concat (rebuilt) .. do_intercolour (text:sub (last))
+end
+
+local do_message = function (text)
+	local rebuilt, last = {""}, 1
+	for run, link, endpos in text:gmatch ('(.-)(%f[%g]https?://%g+)()') do
+		last = endpos
+		table.insert (rebuilt, do_interlink (run) .. link)
+	end
+	return table.concat (rebuilt) .. do_interlink (text:sub (last))
+end
+
+-- XXX: sadly it won't typically highlight primes in our own messages,
+-- unless IRCv3 echo-message is on
+xC.hook_irc (function (hook, server, line)
+	local start, message = line:match ("^(.- PRIVMSG .- :)(.*)$")
+	return message and start .. do_message (message) or line
+end)
diff --git a/plugins/xC/slack.lua b/plugins/xC/slack.lua
new file mode 100644
index 0000000..c1a08de
--- /dev/null
+++ b/plugins/xC/slack.lua
@@ -0,0 +1,147 @@
+--
+-- slack.lua: try to fix up UX when using the Slack IRC gateway
+--
+-- Copyright (c) 2017, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+local servers = {}
+local read_servers = function (v)
+	servers = {}
+	for name in v:lower ():gmatch "[^,]+" do
+		servers[name] = true
+	end
+end
+
+-- This is a reverse list of Slack's automatic emoji, noseless forms
+local unemojify, emoji, emoji_default = false, {}, {
+	heart                        = "<3",
+	broken_heart                 = "</3",
+	sunglasses                   = "8)",
+	anguished                    = "D:",
+	cry                          = ":'(",
+	monkey_face                  = ":o)",
+	kiss                         = ":*",
+	smiley                       = "=)",
+	smile                        = ":D",
+	wink                         = ";)",
+	laughing                     = ":>",
+	neutral_face                 = ":|",
+	open_mouth                   = ":o",
+	angry                        = ">:(",
+	slightly_smiling_face        = ":)",
+	disappointed                 = ":(",
+	confused                     = ":/",
+	stuck_out_tongue             = ":p",
+	stuck_out_tongue_winking_eye = ";p",
+}
+local load_emoji = function (extra)
+	emoji = {}
+	for k, v in pairs (emoji_default) do emoji[k] = v end
+	for k, v in extra:gmatch "([^,]+) ([^,]+)" do emoji[k] = v end
+end
+
+xC.setup_config {
+	servers = {
+		type = "string_array",
+		default = "\"\"",
+		comment = "list of server names that are Slack IRC gateways",
+		on_change = read_servers
+	},
+	unemojify = {
+		type = "boolean",
+		default = "true",
+		comment = "convert emoji to normal ASCII emoticons",
+		on_change = function (v) unemojify = v end
+	},
+	extra_emoji = {
+		type = "string_array",
+		default = "\"grinning :)),joy :'),innocent o:),persevere >_<\"",
+		comment = "overrides or extra emoji for unemojify",
+		on_change = function (v) load_emoji (v) end
+	}
+}
+
+-- We can handle external messages about what we've supposedly sent just fine,
+-- so let's get rid of that "[username] some message sent from the web UI" crap
+xC.hook_irc (function (hook, server, line)
+	local msg, us = xC.parse (line), server.user
+	if not servers[server.name] or msg.command ~= "PRIVMSG" or not us
+		or msg.params[1]:lower () ~= us.nickname:lower () then return line end
+
+	-- Taking a shortcut to avoid lengthy message reassembly
+	local quoted_nick = us.nickname:gsub ("[%^%$%(%)%%%.%[%]%*%+%-%?]", "%%%0")
+	local text = line:match ("^.- PRIVMSG .- :%[" .. quoted_nick .. "%] (.*)$")
+	if not text then return line end
+	return ":" .. us.nickname .. "!" .. server.irc_user_host .. " PRIVMSG "
+		.. msg.prefix:match "^[^!@]*" .. " :" .. text
+end)
+
+-- Unfuck emoji and :nick!nick@irc.tinyspeck.com MODE #channel +v nick : active
+xC.hook_irc (function (hook, server, line)
+	if not servers[server.name] then return line end
+	if unemojify then
+		local start, text = line:match ("^(.- PRIVMSG .- :)(.*)$")
+		if start then return start .. text:gsub (":([a-z_]+):", function (name)
+			if emoji[name] then return emoji[name] end
+			return ":" .. name .. ":"
+		end) end
+	end
+	return line:gsub ("^(:%S+ MODE .+) : .*", "%1")
+end)
+
+-- The gateway simply ignores the NAMES command altogether
+xC.hook_input (function (hook, buffer, input)
+	if not buffer.channel or not servers[buffer.server.name]
+		or not input:match "^/names%s*$" then return input end
+
+	local users = buffer.channel.users
+	table.sort (users, function (a, b)
+		if a.prefixes > b.prefixes then return true end
+		if a.prefixes < b.prefixes then return false end
+		return a.user.nickname < b.user.nickname
+	end)
+
+	local names = "Users on " .. buffer.channel.name .. ":"
+	for i, chan_user in ipairs (users) do
+		names = names .. " " .. chan_user.prefixes .. chan_user.user.nickname
+	end
+	buffer:log (names)
+end)
+
+xC.hook_completion (function (hook, data, word)
+	local chan = xC.current_buffer.channel
+	local server = xC.current_buffer.server
+	if not chan or not servers[server.name] then return end
+
+	-- In /commands there is typically no desire at all to add the at sign
+	if data.location == 1 and data.words[1]:match "^/" then return end
+
+	-- Handle both when the at sign is already there and when it is not
+	local needle = word:gsub ("^@", ""):lower ()
+
+	local t = {}
+	local try = function (name)
+		if data.location == 0 then name = name .. ":" end
+		if name:sub (1, #needle):lower () == needle then
+			table.insert (t, "@" .. name)
+		end
+	end
+	for _, chan_user in ipairs (chan.users) do
+		try (chan_user.user.nickname)
+	end
+	for _, special in ipairs { "channel", "here" } do
+		try (special)
+	end
+	return t
+end)
diff --git a/plugins/xC/thin-cursor.lua b/plugins/xC/thin-cursor.lua
new file mode 100644
index 0000000..d0fbf38
--- /dev/null
+++ b/plugins/xC/thin-cursor.lua
@@ -0,0 +1,27 @@
+--
+-- thin-cursor.lua: set a thin cursor
+--
+-- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+-- If tmux doesn't work, add the following to its configuration:
+--   set -as terminal-overrides ',*:Ss=\E[%p1%d q:Se=\E[2 q'
+-- Change the "2" as per http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
+
+local out = io.output ()
+out:write ("\x1b[6 q"):flush ()
+
+-- By registering a global variable, we get notified about plugin unload
+x = setmetatable ({}, { __gc = function ()
+	out:write ("\x1b[2 q"):flush ()
+end })
diff --git a/plugins/xC/utm-filter.lua b/plugins/xC/utm-filter.lua
new file mode 100644
index 0000000..82c4522
--- /dev/null
+++ b/plugins/xC/utm-filter.lua
@@ -0,0 +1,62 @@
+--
+-- utm-filter.lua: filter out Google Analytics bullshit from URLs
+--
+-- Copyright (c) 2015, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+-- A list of useless URL parameters that don't affect page function
+local banned = {
+	gclid        = 1,
+
+	utm_source   = 1,
+	utm_medium   = 1,
+	utm_term     = 1,
+	utm_content  = 1,
+	utm_campaign = 1,
+}
+
+-- Go through a parameter list and throw out any banned elements
+local do_args = function (args)
+	local filtered = {}
+	for part in args:gmatch ("[^&]+") do
+		if not banned[part:match ("^[^=]*")] then
+			table.insert (filtered, part)
+		end
+	end
+	return table.concat (filtered, "&")
+end
+
+-- Filter parameters in both the query and the fragment part of an URL
+local do_single_url = function (url)
+	return url:gsub ('^([^?#]*)%?([^#]*)', function (start, query)
+		local clean = do_args (query)
+		return #clean > 0 and start .. "?" .. clean or start
+	end, 1):gsub ('^([^#]*)#(.*)', function (start, fragment)
+		local clean = do_args (fragment)
+		return #clean > 0 and start .. "#" .. clean or start
+	end, 1)
+end
+
+local do_text = function (text)
+	return text:gsub ('%f[%g]https?://%g+', do_single_url)
+end
+
+xC.hook_irc (function (hook, server, line)
+	local start, message = line:match ("^(.* :)(.*)$")
+	return message and start .. do_text (message) or line
+end)
+
+xC.hook_input (function (hook, buffer, input)
+	return do_text (input)
+end)