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+# mcompletescript
+
+![](https://img.shields.io/badge/written%20in-Lua-blue)
+
+A PtokaX extension adding several features.
+
+User features:
+- Catchup chat history
+- Full chat archive
+- User registration and password change support
+- Block search terms
+- Block invisible space characters in user nicks
+- Group chat support with UserCommand integration
+
+Administrator features:
+- Manage ptokax scripts
+- Retrieve hub statistics
+- Impersonate users
+
+Tags: nmdc
+
+
+## Download
+
+- [⬇️ mCompleteScript_v20.lua](dist-archive/mCompleteScript_v20.lua) *(21.02 KiB)*
diff --git a/dist-archive/mCompleteScript_v20.lua b/dist-archive/mCompleteScript_v20.lua
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+--[[      _ _ /~` _  _ _  _ | _ _|_ _ (~ _ _. _ _|_
+         | | |\_,(_)| | ||_)|(/_ | (/__)(_| ||_) |     v21
+                         |                   |
+History: Mappy v1..17 2008-2009, v18 Jan 2010, v19 Dec 2012, v20 Jan 2013, v21 Aug 2013
+For time/date formatting, see lua.org/pil/22.1.html
+]]
+
+-----------------------------------------------------------[ options ]
+
+-- Configure features
+bBlockInvisibleCharacters = false
+bBlockIllegalSearches     = false
+bEnableCatchup            = true
+bEnableRegistration       = true
+bEnableUserLocations      = false
+bEnableImpersonate        = false
+bEnableChatLogging        = true
+bEnableGroupChat          = true
+
+il         = 15   -- Number of chat log messages to keep in memory
+tf = "[%H.%M]"    -- Format of chat log timestamps
+AdminLevel = 0    -- Permission required for admin features (by default 0 is 'Master')
+RegLevel   = 3    -- Permission given upon registration (by default 3 is 'Registered')
+PLL        = 5    -- Minimum password length (must be at least one)
+
+-- Words that flag searches;
+badwords = {"clop"}
+
+-- Settings for chat logs
+chatLogPath        = Core.GetPtokaXPath().."logs/%B - %Y - 127.0.0.1.txt"
+chatLogTimeFormat  = "%Y-%m-%d %H:%M:%S"
+
+-- Settings for group chats
+groupChatPruneCheckEvery = 30
+groupChatTimeoutAfter    = 15*60
+
+-- Strings
+SZ_REG_CONNECTED   = "Thank you for using a registered nickname!"
+SZ_UNREG_CONNECTED = "Want to secure your nickname? Register it."
+SZ_REG_COMPLETED   = "Your nickname is now registered. In future, log on with your password."
+SZ_INVISIBLE_CHAR  = "Sorry, remove all invisible characters from your name to reconnect."
+SZ_REDIR_REASON    = "Rearranging network, please be patient..."
+SZ_E_DISABLED      = "* Feature disabled."
+SZ_E_SYNTAX_ERROR  = "* Syntax error."
+SZ_E_UNAUTHORISED  = "* Unauthorised."
+SZ_E_SCRIPT_ERROR  = "* Error performing script operation."
+
+SZ_GCHAT_CLOSING   = "## Closing group chat..."
+SZ_GCHAT_AWAYMSG   = "Away"
+
+-----------------------------------------------------------[ data storage ]
+
+groupchats = {}
+groupChatTimer = nil
+ml = {""}
+mp = -1
+hall = {
+	-- 1-indexed,
+	"Rochester and Rutherford", -- 8..15
+	"Ilam Apartments",          -- 16..31
+	"Ilam Apartments",
+	"Bishop Julius",            -- 32..39
+	"College House",            -- 40..47
+	"University Hall",          -- 48..55
+	"Sonada"                    -- 56..63
+}
+-----------------------------------------------------------[ connections ]
+
+function OpConnected(user) SC(user) end
+function RegConnected(user) SC(user) end
+
+function UserConnected(user)
+	if bBlockInvisibleCharacters then
+		-- Only filters unregistered users
+		if string.find(user.sNick, "�") then
+			Core.SendToUser(user, "* "..SZ_INVISIBLE_CHAR)
+			BanMan.TempBanNick(user.sNick, 1, "Use of invisible character", Core.GetHubSecAlias)
+			Core.SendToOps("<"..Core.GetHubSecAlias.."> "..user.sNick.." tried to use an invisible character!")
+		end
+	end	
+	SC(user)
+end
+
+function SC(user, sendMessages)
+	-- CONTEXT_HUB = 0x01
+	-- CONTEXT_USER = 0x02
+	if sendMessages == nil then sendMessages = true end
+	if not user then return end
+	
+	-- Clear existing
+	AddUSC(user, "255 3", "", "")
+	
+	-- Locations
+	if (bEnableUserLocations) then
+		AddUSC(user, "1 2", "Get User Location", "!locate %[nick]")
+	end
+	
+	-- Registration
+	if (bEnableRegistration) then
+		if user.iProfile == RegLevel then
+			if sendMessages then Core.SendToUser(user, "* "..SZ_REG_CONNECTED) end
+			AddUSC(user, "1 1", "Change your password...", "!reg %[line:Enter a password]")
+		else
+			if sendMessages then Core.SendToUser(user, "* "..SZ_UNREG_CONNECTED) end
+			AddUSC(user, "1 1", "Register your nick...", "!reg %[line:Enter a password]")
+		end
+	end
+	
+	-- Catchup
+	if (bEnableCatchup) then
+		if sendMessages then SendCatchup(user) end
+		AddUSC(user, "1 1", "Get chat history", "!catchup")		
+	end
+	
+	-- Impersonation
+	if (bEnableImpersonate or user.iProfile == AdminLevel) then
+		AddUSC(user, "1 2", "Impersonate\\Say as user...", "!yuo %[nick] %[line:Enter text]")
+		AddUSC(user, "1 2", "Impersonate\\Action as user [normal]...", "!yuo %[nick] /me %[line:Enter text]")
+		AddUSC(user, "1 2", "Impersonate\\Action as user [system]...", "!you %[nick] %[line:Enter text]")
+		AddUSC(user, "0 2", "", "")
+		AddUSC(user, "1 3", "Impersonate\\Send system message...", "!you %[line:Enter text]")
+	end
+	
+	-- Group chats
+	if (bEnableGroupChat) then
+		AddUSC(user, "1 1", "Group chat\\New group chat", "!groupchat_new")
+		local foundAnyChats = false
+		for botnick, grinfo in pairs(groupchats) do
+			if grinfo["owner"] == user.sNick then
+				if not foundAnyChats then
+					AddUSC(user, "1 1", "Group chat\\-", "")
+					foundAnyChats = true
+				end
+				AddUSC(user, "1 1", "Group chat\\Close chat ["..botnick.."]", "!groupchat_close "..botnick)
+				AddUSC(user, "1 2", "Invite user to join ["..botnick.."]", "!groupchat_invite "..botnick.." %[nick]")
+			end
+		end		
+	end
+	
+	-- Admin tasks
+	if (user.iProfile == AdminLevel) then
+		
+		AddUSC(user, "1 1", "Admin\\Restart PtokaX", "!restart")
+		AddUSC(user, "1 1", "Admin\\Redirect all users...", "!redirectallusers %[line:Redirect address]")
+		AddUSC(user, "1 1", "Admin\\Set hub title...", "!sethubtitle %[line:Hub title]")
+		AddUSC(user, "1 1", "Admin\\Reload MOTD from disk", "!reload-motd")
+		AddUSC(user, "0 1", "Admin\\-", "")
+		AddUSC(user, "1 2", "Admin\\Look up user password", "!get-password %[nick]")
+		if bEnableCatchup then
+			AddUSC(user, "1 1", "Admin\\Flush catchup ring buffer", "!catchup-flush")
+		end
+		AddUSC(user, "1 1", "Admin\\Chat as "..Core.GetHubSecAlias().."...", "!yuo "..Core.GetHubSecAlias().." %[line:Enter text]")
+		AddUSC(user, "1 1", "Admin\\Get hub stats", "!get-stats")
+		AddUSC(user, "1 1", "Admin\\Refresh menu", "!refreshmenu")
+		
+		-- Scripts menu
+		
+		AddUSC(user, "0 1", "Admin\\-", "")
+		ScriptMan.Refresh()
+		for i,v in ipairs(ScriptMan.GetScripts()) do
+			local title = "Admin\\Scripts\\["..(v.bEnabled and "X" or "  ").."] "..v.sName.."\\"
+			if (v.bEnabled) then
+				AddUSC(user, "1 1", title.."Disable", "!stop-script "..v.sName)
+			else
+				AddUSC(user, "1 1", title.."Enable", "!start-script "..v.sName)
+			end
+			AddUSC(user, "1 1", title.."Restart", "!restart-script "..v.sName)
+		end		
+		
+	end	
+end
+
+-----------------------------------------------------------[ main parsing ]
+
+triggers = {
+
+	-- Usage: !locate username
+	["!locate"] = function(user, data, t)
+		if not bEnableUserLocations then return Core.SendToUser(user, SZ_E_DISABLED) end
+		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
+			
+		Core.SendToUser(user, GetHallFromIP(t[2]))
+	end,
+	
+	-- Usage: !reg password
+	["!reg"] = function(user, data, t)
+		if not bEnableRegistration then return Core.SendToUser(user, SZ_E_DISABLED) end		
+		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
+		
+		if string.len(t[2])>=PLL then
+			if RegMan.GetReg(user.sNick)==nil then
+				RegMan.AddReg(user.sNick, t[2], RegLevel)
+				Core.SendToUser(user, "* "..SZ_REG_COMPLETED)
+			else
+				RegMan.ChangeReg(user.sNick, t[2], RegLevel)
+				Core.SendToUser(user, "* Password changed.")
+			end
+			RegMan.Save()
+		else
+			Core.SendToUser(user, "* Passwords must be at least "..PLL.." characters long.")
+		end
+	end,
+	
+	-- Usage: !catchup
+	["!catchup"] = function(user, data, t)
+		if not bEnableCatchup then return Core.SendToUser(user, SZ_E_DISABLED) end
+		
+		SendCatchup(user)
+	end,	
+	
+	-- Action as user
+	-- Usage: !you their-nick message goes here
+	["!you"] = function(user, data, t)
+		if bEnableImpersonate or user.iProfile == AdminLevel then
+			local m
+			_,m=s2(data)
+			_,m=s2(m)
+			Core.SendToAll("* "..m)
+			logCatchup("* "..m)
+		else
+			Core.SendToUser(user, SZ_E_DISABLED)
+		end				
+	end,
+	
+	-- Say as user
+	-- Usage: !yuo their-nick message goes here
+	["!yuo"] = function(user, data, t)
+		if bEnableImpersonate or user.iProfile == AdminLevel then
+			local m, u, mg
+			_,m=s2(data)
+			_,m=s2(m)
+			u,mg=s2(m)
+			Core.SendToAll("<"..u.."> "..mg)
+			logCatchup("<"..u.."> "..mg)
+		else
+			Core.SendToUser(user, Z_E_DISABLED)
+		end
+	end,
+	
+	-- Initiate a group chat
+	-- Usage: !groupchat_new
+	["!groupchat_new"] = function(user, data, t)
+		if bEnableGroupChat or user.iProfile == AdminLevel then
+			if #t ~= 1 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
+			groupchat_init(user.sNick)
+		else
+			Core.SendToUser(user, Z_E_DISABLED)
+		end
+	end,
+	
+	-- Invite a user to a group chat under your control
+	-- Usage: !groupchat_invite botnick friendnick
+	["!groupchat_invite"] = function(user, data, t)
+		if bEnableGroupChat or user.iProfile == AdminLevel then
+			if #t ~= 3 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
+			groupchat_invite(user, t[2], t[3])
+		else
+			Core.SendToUser(user, Z_E_DISABLED)
+		end
+	end,
+	
+	-- Close a group chat under your control
+	-- Usage: !groupchat_close botnick
+	["!groupchat_close"] = function(user, data, t)
+		if bEnableGroupChat or user.iProfile == AdminLevel then
+			if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
+			groupchat_end(user, t[2])
+		else
+			Core.SendToUser(user, Z_E_DISABLED)
+		end
+	end
+	
+}
+adminTriggers = {
+
+	-- Usage: !get-password their-nick
+	["!get-password"] = function(user, data, t)
+		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
+		
+		local reguser = RegMan.GetReg(t[2])
+		if reguser then
+			Core.SendToUser(user, "User "..reguser.sNick.." has password '"..reguser.sPassword.."'")
+		else
+			Core.SendToUser(user, "User "..t[2].." not registered.")
+		end
+	end,
+
+	-- Usage: !reload-motd
+	["!reload-motd"] = function(user, data, t)
+		local motd = readFile(Core.GetPtokaXPath().."cfg/Motd.txt", "rb")
+		if motd then
+			SetMan.SetMOTD(motd)
+			SetMan.Save()
+			Core.SendToUser(user, "<"..Core.GetHubSecAlias().."> "..SetMan.GetMOTD())
+		else
+			Core.SendToUser(user, "* Error opening '"..Core.GetPtokaXPath().."cfg/Motd.txt'")
+		end		
+	end,
+	
+	-- Usage: !redirectallusers target-address
+	["!redirectallusers"] = function(user, data, t)
+		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end
+		
+		local allUsers = Core.GetOnlineUsers()
+		for _, u in pairs(allUsers) do
+			Core.SendToUser(user, "* Redirecting ".. u.sNick .." to "..t[2])
+			Core.Redirect(u, t[2], SZ_REDIR_REASON)
+		end
+	end,
+	
+	-- Usage: !refreshmenu
+	["!refreshmenu"] = function(user, data, t)
+		SC(user, false)
+	end,
+	
+	-- Usage: !start-script filename.lua
+	["!start-script"] = function(user, data, t)
+		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end		
+		if (ScriptMan.StartScript(t[2]) == nil) then Core.SendToUser(user, SZ_E_SCRIPT_ERROR) end
+		
+		Core.SendToUser(user, "* Script "..t[2].." started.");
+		SetMan.Save()
+		SC(user, false)
+	end,
+	
+	-- Usage: !stop-script filename.lua
+	["!stop-script"] = function(user, data, t)
+		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end		
+		if (ScriptMan.StopScript(t[2]) == nil) then Core.SendToUser(user, SZ_E_SCRIPT_ERROR) end
+		
+		Core.SendToUser(user, "* Script "..t[2].." stopped.");
+		SetMan.Save()
+		SC(user, false)
+	end,
+		
+	-- Usage: !restart-script filename.lua
+	["!restart-script"] = function(user, data, t)
+		if #t ~= 2 then return Core.SendToUser(user, SZ_E_SYNTAX_ERROR) end		
+		if (ScriptMan.RestartScript(t[2]) == nil) then Core.SendToUser(user, SZ_E_SCRIPT_ERROR) end
+		
+		Core.SendToUser(user, "* Script "..t[2].." restarted.");
+		SetMan.Save()
+		SC(user, false)
+	end,
+	
+	-- Usage: !get-stats
+	["!get-stats"] = function(user, data, t)
+		Core.SendToUser(user, "* Peak users this boot: "..Core.GetActualUsersPeak())
+		Core.SendToUser(user, "* Peak users all time: "..Core.GetMaxUsersPeak())
+		Core.SendToUser(user, "* Current share: "..Core.GetCurrentSharedSize())
+		Core.SendToUser(user, "* Uptime: "..Core.GetUpTime().." seconds")
+	end,
+	
+	-- Usage: !catchup-flush
+	["!catchup-flush"] = function(user, data, t)
+		flushCatchup()
+		Core.SendToUser(user, "* Catchup flushed.")
+	end,
+	
+	-- Usage: !sethubtitle title goes here
+	["!sethubtitle"] = function(user, data, t)
+		SetMan.SetString(0, table.concat(t, " ", 2))
+		SetMan.Save()
+	end,
+	
+}
+
+function ChatArrival(user, data)
+	local validcommand=false
+
+	if (string.sub(data, 1, 1) == "<" ) then
+		data=string.sub(data, 1, string.len(data) -1)
+		t = {}
+		for k in string.gmatch(data, "%s+([^%s]+)") do
+			table.insert(t, k)
+		end
+		
+		if (#t>=1 and triggers[t[1]]) then
+			triggers[t[1]](user, data, t)
+			return true
+			
+		elseif (#t>=1 and user.iProfile == AdminLevel and adminTriggers[t[1]]) then
+			adminTriggers[t[1]](user, data, t)
+			return true
+		
+		elseif t[1] and string.sub(t[1], 1, 1) == "!" then
+			-- Don't add potential system commands to catchup/logs
+			
+		else
+			logCatchup(data:sub(1)) --, -2)) --string.len(data)))
+			logChat(nmdc_unescape(data:sub(1))) --, -2)))
+		end
+		
+	end
+	
+end
+
+function ToArrival(user, data)
+	-- Parse data and determine whether it's intended for any groupchat bots
+	local recipient = data:gsub("%$To: ([^%s]+) From: [^%s]+ %$<[^>]+> (.*)|", "%1")
+	local body      = data:gsub("%$To: ([^%s]+) From: [^%s]+ %$<[^>]+> (.*)|", "%2")
+	
+	-- Core.SendToUser(user, nmdc_escape(data))
+	
+	-- Core.SendToUser(user, "got recipient ["..recipient.."] and body ["..body.."]")
+	
+	if groupchats[recipient] then
+		groupchat_sayas(recipient, user.sNick, body)
+		return true -- abort
+	else	
+		return false -- process normally
+	end
+end
+
+function OnStartup()
+	-- Create groupchat pruner
+	groupChatTimer = TmrMan.AddTimer(groupChatPruneCheckEvery * 1000, "groupchat_prune")
+end
+
+-----------------------------------------------------------[ impersonation ]
+
+function s2(inp)
+	sp = string.find(inp, " ")
+	if sp==nil then sp=0 end
+	return string.sub(inp, 1, sp-1), string.sub(inp, sp+1)
+end
+
+-----------------------------------------------------------[ group chat ]
+
+function groupchat_init(ownernick)
+	-- Generate a nick for the bot by adding numbers to the user's nick until
+	--  one is not currently in use
+	local suffix = 1
+	while true do
+		-- Core.GetUser doesn't include script bots
+		if Core.GetUser(ownernick .. suffix) == nil and not groupchats[ownernick..suffix] then
+			break
+		end
+	
+		suffix = suffix + 1
+		if suffix > 100 then
+			Core.SendToNick(ownernick, "Error: Couldn't pick a group chat username")
+			return
+		end
+	end
+	local botnick = ownernick..suffix
+	
+	-- Register bot
+	if not Core.RegBot(botnick, "", "", false) then
+		Core.SendToNick(ownernick, "Error: Couldn't start group chat")
+		return
+	end
+	
+	-- Save all data
+	groupchats[botnick] = {
+		["owner"] = ownernick,
+		["last"] = os.time(),
+		["users"] = {
+			[ownernick] = true
+		}
+	}
+	
+	-- Refresh usercommands
+	SC( Core.GetUser(ownernick), false )
+	
+	groupchat_say(botnick, "## Joins: "..ownernick)
+end
+
+-- Owner invites a user into an existing group chat
+function groupchat_invite(user, botnick, friendnick)
+	if groupchats[botnick] and  groupchats[botnick]["owner"] == user.sNick then -- only owner can invite
+		if Core.GetUser(friendnick) then -- Check if user's online
+		
+			-- Add user and notify participants
+			groupchats[botnick]["users"][friendnick] = true
+			
+			-- Notify self of existing participants
+			for peer,_ in pairs(groupchats[botnick]["users"]) do
+				local isHost = ""
+				if (groupchats[botnick]["owner"] == peer) then
+					isHost = " (host)"
+				end
+				if peer ~= friendnick then
+					-- we go last
+					Core.SendPmToNick(friendnick, botnick, "## Joins: "..peer..isHost)
+				end
+			end
+			
+			-- Notify existing participants (and self) of joining
+			groupchat_say(botnick, "## Joins: "..friendnick) -- updates mtime
+			
+		else
+			Core.SendToUser(user, "Error: User not online")
+		end			
+	else
+		Core.SendToUser(user, SZ_E_UNAUTHORISED) -- nonexistent or not yours
+	end
+end
+
+-- Pass user as well, so that administrators can prune groupchat bots.
+function groupchat_end(user, botnick)
+	if groupchats[botnick] then
+		if groupchats[botnick]["owner"] == user.sNick or user.iProfile == AdminLevel then
+			-- End chat
+			groupchat_remove(botnick)
+		else
+			-- Not allowed
+			Core.SendToUser(user, SZ_E_UNAUTHORISED)
+		end
+	end
+end
+
+-- Every minute or so, prune group chats that havn't had any replies in a while. 
+function groupchat_prune()
+	if #groupchats then
+		for botnick, gcdata in pairs(groupchats) do
+			if (os.time() - gcdata["last"]) > groupChatTimeoutAfter then
+				groupchat_remove(botnick)
+			end
+		end
+	end
+end
+
+-- Explicitly remove a group chat. Only called by other groupchat_ helper
+--  functions
+function groupchat_remove(botnick)
+	if groupchats[botnick] then
+		-- Send leaving message to any still-connected users
+		groupchat_say(botnick, SZ_GCHAT_CLOSING)
+		
+		-- Part the bot
+		Core.UnregBot(botnick)
+	
+		local owner = groupchats[botnick]["owner"]
+	
+		-- Remove from groupchat registry
+		groupchats[botnick] = nil
+		
+		-- Refresh usercommands for the host
+		SC( Core.GetUser(owner), false )
+	end
+end
+
+-- Explicitly say a message into a group chat. Only called by other groupchat_
+--  helper functions
+function groupchat_say(botnick, message)
+	if groupchats[botnick] then
+		for destnick, _ in pairs(groupchats[botnick]["users"]) do
+			Core.SendPmToNick( destnick, botnick, message )
+		end
+		groupchats[botnick]["last"] = os.time()
+	end
+end
+
+-- Say a message from a user (i.e. don't echo it back to them)
+function groupchat_sayas(botnick, selfnick, message)
+	if groupchats[botnick] then
+		local valid = false;
+		for destnick, _ in pairs(groupchats[botnick]["users"]) do
+			if destnick == selfnick then
+				valid = true
+				break
+			end
+		end
+		if valid then
+			for destnick, _ in pairs(groupchats[botnick]["users"]) do
+				if destnick ~= selfnick then
+					Core.SendPmToNick(destnick, botnick, "<"..selfnick.."> "..message)
+				end
+			end
+		else
+			Core.SendPmToNick(selfnick, botnick, SZ_GCHAT_AWAYMSG) -- pretend we're not here
+		end
+	end
+end
+
+-----------------------------------------------------------[ search parsing ]
+
+function SearchArrival(user, data)
+	if bBlockIllegalSearches then
+		sstr=data
+		while string.find(sstr, "?") do
+			sstr=string.sub(sstr, string.find(sstr,"?")+1)
+		end
+		sstr="$"..string.lower( string.sub(sstr,1,string.len(sstr)-1) )
+		
+		t = {}
+		for k in string.gmatch(sstr, "%$([^%$]+)") do
+			table.insert(t, k)
+		end
+		sstr=table.concat(t, " ")
+
+		if string.sub(sstr, 1, 4) ~= "tth:" then 
+			local showbanner=false
+			for cnt=1,#badwords do
+				if string.find(sstr, badwords[cnt]) then 
+					showbanner=true
+					break
+				end
+			end
+			if showbanner then
+				Core.SendToAll("<"..Core.GetHubSecAlias().."> "..user.sNick.." just searched for '"..sstr.."'!")
+				return true		-- disable the search
+			end
+		end
+	end
+end
+
+-----------------------------------------------------------[ location ]
+
+function GetHallFromIP(userNick)
+	if Core.GetUser(userNick) == nil then
+		return "* User "..userNick.." doesn't have a location."
+	else
+		-- Dumb check of third digit in IP
+		subnet = string.gsub(Core.GetUser(userNick).sIP, "%d+%D%d+%D(%d+)%D%d+", "%1")
+		subnet = math.floor(subnet / 8)
+		if hall[subnet]==nil then
+			return "* User "..userNick.." is located somewhere unknown"
+		else
+			return "* User "..userNick.." is located at "..hall[subnet]
+		end
+	end
+end
+
+-----------------------------------------------------------[ catchup ]
+
+function SendCatchup(user)
+	local sz = getRange(ml, isz(mp), il)..getRange(ml, 0, isz(mp))
+	Core.SendToNick(user.sNick, "* Showing up to "..il.." messages.."..sz)
+	Core.SendToNick(user.sNick, "* Catchup completed.\n")
+end
+
+function isz(n) return (n + 1 + il) % il end
+
+function logCatchup(text)
+	mp = isz(mp)
+	ml[mp] = os.date(tf).." "..text
+end
+
+function flushCatchup()
+	ml = {""}
+	mp = -1
+end
+
+-----------------------------------------------------------[ chatlogs ]
+
+function logChat(text)
+	local logfile = os.date(chatLogPath)
+	local f = io.open(logfile, "a+")
+	f:write("["..os.date(chatLogTimeFormat).."] "..text.."\n")
+	f:close()
+end
+
+-----------------------------------------------------------[ general ]
+
+function onError(sErrMsg)
+	Core.SendPmToOps(Core.GetHubSecAlias, "The hub script has broken down!\n"..sErrMsg)	
+end
+
+function AddUSC(user, mode, menu, cstr)
+	Core.SendToUser(user, "$UserCommand "..mode.." "..menu.."$<%[mynick]> "..cstr.."&#124;")
+end
+
+-- @return nil|string
+function readFile(path)
+	local f = io.open(path, "rb")
+	if (f) then
+		f:close()
+		
+		lines = {}
+		for line in io.lines(path) do
+			lines[#lines + 1] = line
+		end
+		return table.concat(lines, "\n")
+	end
+	return nil
+end
+
+-- @return string
+function getRange(array, first, last) 
+	local c = first
+	local s = ""
+	while not (c >= last or array[c] == nil) do
+		s = s.."\n"..array[c]
+		c = c + 1
+	end
+	return s
+end
+
+function nmdc_escape(message)
+	local r = message:gsub("&", "&amp;"):gsub("|", "&#124;"):gsub("%$", "&#36;") -- escape $ sign
+	return r -- otherwise there are two arguments
+end
+
+function nmdc_unescape(message)
+	local r = message:gsub("&#36;", "$"):gsub("&#124;", "|"):gsub("&amp;", "&")
+	return r
+end
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