Add success and output return values to chat commands

2 files changed, 217 insertions, 244 deletions

diff --git a/builtin/game/chatcommands.lua b/builtin/game/chatcommands.lua
index fb08d2a6b..39425f0eb 100644
--- a/builtin/game/chatcommands.lua
+++ b/builtin/game/chatcommands.lua
@@ -19,16 +19,21 @@ core.register_on_chat_message(function(name, message)
 		param = ""
 	end
 	local cmd_def = core.chatcommands[cmd]
-	if cmd_def then
-		local has_privs, missing_privs = core.check_player_privs(name, cmd_def.privs)
-		if has_privs then
-			cmd_def.func(name, param)
-		else
-			core.chat_send_player(name, "You don't have permission to run this command (missing privileges: "..table.concat(missing_privs, ", ")..")")
+	if not cmd_def then
+		return false
+	end
+	local has_privs, missing_privs = core.check_player_privs(name, cmd_def.privs)
+	if has_privs then
+		local success, message = cmd_def.func(name, param)
+		if message then
+			core.chat_send_player(name, message)
 		end
-		return true -- handled chat message
+	else
+		core.chat_send_player(name, "You don't have permission"
+				.. " to run this command (missing privileges: "
+				.. table.concat(missing_privs, ", ") .. ")")
 	end
-	return false
+	return true  -- Handled chat message
 end)
 
 --
@@ -45,13 +50,17 @@ core.register_chatcommand("me", {
 
 core.register_chatcommand("help", {
 	privs = {},
-	params = "(nothing)/all/privs/<cmd>",
+	params = "[all/privs/<cmd>]",
 	description = "Get help for commands or list privileges",
 	func = function(name, param)
-		local format_help_line = function(cmd, def)
+		local function format_help_line(cmd, def)
 			local msg = "/"..cmd
-			if def.params and def.params ~= "" then msg = msg .. " " .. def.params end
-			if def.description and def.description ~= "" then msg = msg .. ": " .. def.description end
+			if def.params and def.params ~= "" then
+				msg = msg .. " " .. def.params
+			end
+			if def.description and def.description ~= "" then
+				msg = msg .. ": " .. def.description
+			end
 			return msg
 		end
 		if param == "" then
@@ -63,102 +72,90 @@ core.register_chatcommand("help", {
 				end
 			end
 			table.sort(cmds)
-			core.chat_send_player(name, "Available commands: "..table.concat(cmds, " "))
-			core.chat_send_player(name, "Use '/help <cmd>' to get more information, or '/help all' to list everything.")
+			return true, "Available commands: " .. table.concat(cmds, " ") .. "\n"
+					.. "Use '/help <cmd>' to get more information,"
+					.. " or '/help all' to list everything."
 		elseif param == "all" then
 			local cmds = {}
 			for cmd, def in pairs(core.chatcommands) do
 				if core.check_player_privs(name, def.privs) then
-					table.insert(cmds, cmd)
+					table.insert(cmds, format_help_line(cmd, def))
 				end
 			end
 			table.sort(cmds)
-			core.chat_send_player(name, "Available commands:")
-			for _, cmd in ipairs(cmds) do
-				local def = core.chatcommands[cmd]
-				core.chat_send_player(name, format_help_line(cmd, def))
-			end
+			return true, "Available commands:\n"..table.concat(cmds, "\n")
 		elseif param == "privs" then
 			local privs = {}
 			for priv, def in pairs(core.registered_privileges) do
-				table.insert(privs, priv)
+				table.insert(privs, priv .. ": " .. def.description)
 			end
 			table.sort(privs)
-			core.chat_send_player(name, "Available privileges:")
-			for _, priv in ipairs(privs) do
-				local def = core.registered_privileges[priv]
-				core.chat_send_player(name, priv..": "..def.description)
-			end
+			return true, "Available privileges:\n"..table.concat(privs, "\n")
 		else
 			local cmd = param
-			def = core.chatcommands[cmd]
+			local def = core.chatcommands[cmd]
 			if not def then
-				core.chat_send_player(name, "Command not available: "..cmd)
+				return false, "Command not available: "..cmd
 			else
-				core.chat_send_player(name, format_help_line(cmd, def))
+				return true, format_help_line(cmd, def)
 			end
 		end
 	end,
 })
+
 core.register_chatcommand("privs", {
 	params = "<name>",
 	description = "print out privileges of player",
 	func = function(name, param)
-		if param == "" then
-			param = name
-		else
-			--[[if not core.check_player_privs(name, {privs=true}) then
-				core.chat_send_player(name, "Privileges of "..param.." are hidden from you.")
-				return
-			end]]
-		end
-		core.chat_send_player(name, "Privileges of "..param..": "..core.privs_to_string(core.get_player_privs(param), ' '))
+		param = (param ~= "" and param or name)
+		return true, "Privileges of " .. param .. ": "
+			.. core.privs_to_string(
+				core.get_player_privs(param), ' ')
 	end,
 })
 core.register_chatcommand("grant", {
 	params = "<name> <privilege>|all",
 	description = "Give privilege to player",
-	privs = {},
 	func = function(name, param)
 		if not core.check_player_privs(name, {privs=true}) and
 				not core.check_player_privs(name, {basic_privs=true}) then
-			core.chat_send_player(name, "Your privileges are insufficient.")
-			return
+			return false, "Your privileges are insufficient."
 		end
 		local grantname, grantprivstr = string.match(param, "([^ ]+) (.+)")
 		if not grantname or not grantprivstr then
-			core.chat_send_player(name, "Invalid parameters (see /help grant)")
-			return
+			return false, "Invalid parameters (see /help grant)"
 		elseif not core.auth_table[grantname] then
-			core.chat_send_player(name, "Player "..grantname.." does not exist.")
-			return
+			return false, "Player " .. grantname .. " does not exist."
 		end
 		local grantprivs = core.string_to_privs(grantprivstr)
 		if grantprivstr == "all" then
 			grantprivs = core.registered_privileges
 		end
 		local privs = core.get_player_privs(grantname)
-		local privs_known = true
+		local privs_unknown = ""
 		for priv, _ in pairs(grantprivs) do
-			if priv ~= "interact" and priv ~= "shout" and priv ~= "interact_extra" and not core.check_player_privs(name, {privs=true}) then
-				core.chat_send_player(name, "Your privileges are insufficient.")
-				return
+			if priv ~= "interact" and priv ~= "shout" and
+					not core.check_player_privs(name, {privs=true}) then
+				return false, "Your privileges are insufficient."
 			end
 			if not core.registered_privileges[priv] then
-				core.chat_send_player(name, "Unknown privilege: "..priv)
-				privs_known = false
+				privs_unknown = privs_unknown .. "Unknown privilege: " .. priv .. "\n"
 			end
 			privs[priv] = true
 		end
-		if not privs_known then
-			return
+		if privs_unknown ~= "" then
+			return false, privs_unknown
 		end
 		core.set_player_privs(grantname, privs)
-		core.log(name..' granted ('..core.privs_to_string(grantprivs, ', ')..') privileges to '..grantname)
-		core.chat_send_player(name, "Privileges of "..grantname..": "..core.privs_to_string(core.get_player_privs(grantname), ' '))
+		core.log("action", name..' granted ('..core.privs_to_string(grantprivs, ', ')..') privileges to '..grantname)
 		if grantname ~= name then
-			core.chat_send_player(grantname, name.." granted you privileges: "..core.privs_to_string(grantprivs, ' '))
+			core.chat_send_player(grantname, name
+					.. " granted you privileges: "
+					.. core.privs_to_string(grantprivs, ' '))
 		end
+		return true, "Privileges of " .. grantname .. ": "
+			.. core.privs_to_string(
+				core.get_player_privs(grantname), ' ')
 	end,
 })
 core.register_chatcommand("revoke", {
@@ -168,40 +165,44 @@ core.register_chatcommand("revoke", {
 	func = function(name, param)
 		if not core.check_player_privs(name, {privs=true}) and
 				not core.check_player_privs(name, {basic_privs=true}) then
-			core.chat_send_player(name, "Your privileges are insufficient.")
-			return
-		end
-		local revokename, revokeprivstr = string.match(param, "([^ ]+) (.+)")
-		if not revokename or not revokeprivstr then
-			core.chat_send_player(name, "Invalid parameters (see /help revoke)")
-			return
-		elseif not core.auth_table[revokename] then
-			core.chat_send_player(name, "Player "..revokename.." does not exist.")
-			return
-		end
-		local revokeprivs = core.string_to_privs(revokeprivstr)
-		local privs = core.get_player_privs(revokename)
-		for priv, _ in pairs(revokeprivs) do
-			if priv ~= "interact" and priv ~= "shout" and priv ~= "interact_extra" and not core.check_player_privs(name, {privs=true}) then
-				core.chat_send_player(name, "Your privileges are insufficient.")
-				return
+			return false, "Your privileges are insufficient."
+		end
+		local revoke_name, revoke_priv_str = string.match(param, "([^ ]+) (.+)")
+		if not revoke_name or not revoke_priv_str then
+			return false, "Invalid parameters (see /help revoke)"
+		elseif not core.auth_table[revoke_name] then
+			return false, "Player " .. revoke_name .. " does not exist."
+		end
+		local revoke_privs = core.string_to_privs(revoke_priv_str)
+		local privs = core.get_player_privs(revoke_name)
+		for priv, _ in pairs(revoke_privs) do
+			if priv ~= "interact" and priv ~= "shout" and priv ~= "interact_extra" and
+					not core.check_player_privs(name, {privs=true}) then
+				return false, "Your privileges are insufficient."
 			end
 		end
-		if revokeprivstr == "all" then
+		if revoke_priv_str == "all" then
 			privs = {}
 		else
-			for priv, _ in pairs(revokeprivs) do
+			for priv, _ in pairs(revoke_privs) do
 				privs[priv] = nil
 			end
 		end
-		core.set_player_privs(revokename, privs)
-		core.log(name..' revoked ('..core.privs_to_string(revokeprivs, ', ')..') privileges from '..revokename)
-		core.chat_send_player(name, "Privileges of "..revokename..": "..core.privs_to_string(core.get_player_privs(revokename), ' '))
-		if revokename ~= name then
-			core.chat_send_player(revokename, name.." revoked privileges from you: "..core.privs_to_string(revokeprivs, ' '))
-		end
+		core.set_player_privs(revoke_name, privs)
+		core.log("action", name..' revoked ('
+				..core.privs_to_string(revoke_privs, ', ')
+				..') privileges from '..revoke_name)
+		if revoke_name ~= name then
+			core.chat_send_player(revoke_name, name
+					.. " revoked privileges from you: "
+					.. core.privs_to_string(revoke_privs, ' '))
+		end
+		return true, "Privileges of " .. revoke_name .. ": "
+			.. core.privs_to_string(
+				core.get_player_privs(revoke_name), ' ')
 	end,
 })
+
 core.register_chatcommand("setpassword", {
 	params = "<name> <password>",
 	description = "set given password",
@@ -209,27 +210,30 @@ core.register_chatcommand("setpassword", {
 	func = function(name, param)
 		local toname, raw_password = string.match(param, "^([^ ]+) +(.+)$")
 		if not toname then
-			toname = string.match(param, "^([^ ]+) *$")
+			toname = param:match("^([^ ]+) *$")
 			raw_password = nil
 		end
 		if not toname then
-			core.chat_send_player(name, "Name field required")
-			return
+			return false, "Name field required"
 		end
 		local actstr = "?"
 		if not raw_password then
 			core.set_player_password(toname, "")
 			actstr = "cleared"
 		else
-			core.set_player_password(toname, core.get_password_hash(toname, raw_password))
+			core.set_player_password(toname,
+					core.get_password_hash(toname,
+							raw_password))
 			actstr = "set"
 		end
-		core.chat_send_player(name, "Password of player \""..toname.."\" "..actstr)
 		if toname ~= name then
-			core.chat_send_player(toname, "Your password was "..actstr.." by "..name)
+			core.chat_send_player(toname, "Your password was "
+					.. actstr .. " by " .. name)
 		end
+		return true, "Password of player \"" .. toname .. "\" " .. actstr
 	end,
 })
+
 core.register_chatcommand("clearpassword", {
 	params = "<name>",
 	description = "set empty password",
@@ -237,11 +241,10 @@ core.register_chatcommand("clearpassword", {
 	func = function(name, param)
 		toname = param
 		if toname == "" then
-			core.chat_send_player(name, "Name field required")
-			return
+			return false, "Name field required"
 		end
 		core.set_player_password(toname, '')
-		core.chat_send_player(name, "Password of player \""..toname.."\" cleared")
+		return true, "Password of player \"" .. toname .. "\" cleared"
 	end,
 })
 
@@ -251,11 +254,7 @@ core.register_chatcommand("auth_reload", {
 	privs = {server=true},
 	func = function(name, param)
 		local done = core.auth_reload()
-		if done then
-			core.chat_send_player(name, "Done.")
-		else
-			core.chat_send_player(name, "Failed.")
-		end
+		return done, (done and "Done." or "Failed.")
 	end,
 })
 
@@ -293,15 +292,14 @@ core.register_chatcommand("teleport", {
 		p.z = tonumber(p.z)
 		teleportee = core.get_player_by_name(name)
 		if teleportee and p.x and p.y and p.z then
-			core.chat_send_player(name, "Teleporting to ("..p.x..", "..p.y..", "..p.z..")")
 			teleportee:setpos(p)
-			return
+			return true, "Teleporting to "..core.pos_to_string(p)
 		end
 		
 		local teleportee = nil
 		local p = nil
 		local target_name = nil
-		target_name = string.match(param, "^([^ ]+)$")
+		target_name = param:match("^([^ ]+)$")
 		teleportee = core.get_player_by_name(name)
 		if target_name then
 			local target = core.get_player_by_name(target_name)
@@ -311,26 +309,25 @@ core.register_chatcommand("teleport", {
 		end
 		if teleportee and p then
 			p = find_free_position_near(p)
-			core.chat_send_player(name, "Teleporting to "..target_name.." at ("..p.x..", "..p.y..", "..p.z..")")
 			teleportee:setpos(p)
-			return
+			return true, "Teleporting to " .. target_name
+					.. " at "..core.pos_to_string(p)
 		end
 		
 		if core.check_player_privs(name, {bring=true}) then
 			local teleportee = nil
 			local p = {}
 			local teleportee_name = nil
-			teleportee_name, p.x, p.y, p.z = string.match(param, "^([^ ]+) +([%d.-]+)[, ] *([%d.-]+)[, ] *([%d.-]+)$")
-			p.x = tonumber(p.x)
-			p.y = tonumber(p.y)
-			p.z = tonumber(p.z)
+			teleportee_name, p.x, p.y, p.z = param:match(
+					"^([^ ]+) +([%d.-]+)[, ] *([%d.-]+)[, ] *([%d.-]+)$")
+			p.x, p.y, p.z = tonumber(p.x), tonumber(p.y), tonumber(p.z)
 			if teleportee_name then
 				teleportee = core.get_player_by_name(teleportee_name)
 			end
 			if teleportee and p.x and p.y and p.z then
-				core.chat_send_player(name, "Teleporting "..teleportee_name.." to ("..p.x..", "..p.y..", "..p.z..")")
 				teleportee:setpos(p)
-				return
+				return true, "Teleporting " .. teleportee_name
+						.. " to " .. core.pos_to_string(p)
 			end
 			
 			local teleportee = nil
@@ -349,14 +346,15 @@ core.register_chatcommand("teleport", {
 			end
 			if teleportee and p then
 				p = find_free_position_near(p)
-				core.chat_send_player(name, "Teleporting "..teleportee_name.." to "..target_name.." at ("..p.x..", "..p.y..", "..p.z..")")
 				teleportee:setpos(p)
-				return
+				return true, "Teleporting " .. teleportee_name
+						.. " to " .. target_name
+						.. " at " .. core.pos_to_string(p)
 			end
 		end
 
-		core.chat_send_player(name, "Invalid parameters (\""..param.."\") or player not found (see /help teleport)")
-		return
+		return false, 'Invalid parameters ("' .. param
+				.. '") or player not found (see /help teleport)'
 	end,
 })
 
@@ -368,18 +366,15 @@ core.register_chatcommand("set", {
 		local arg, setname, setvalue = string.match(param, "(-[n]) ([^ ]+) (.+)")
 		if arg and arg == "-n" and setname and setvalue then
 			core.setting_set(setname, setvalue)
-			core.chat_send_player(name, setname.." = "..setvalue)
-			return
+			return true, setname .. " = " .. setvalue
 		end
 		local setname, setvalue = string.match(param, "([^ ]+) (.+)")
 		if setname and setvalue then
 			if not core.setting_get(setname) then
-				core.chat_send_player(name, "Failed. Use '/set -n <name> <value>' to create a new setting.")
-				return
+				return false, "Failed. Use '/set -n <name> <value>' to create a new setting."
 			end
 			core.setting_set(setname, setvalue)
-			core.chat_send_player(name, setname.." = "..setvalue)
-			return
+			return true, setname .. " = " .. setvalue
 		end
 		local setname = string.match(param, "([^ ]+)")
 		if setname then
@@ -387,47 +382,33 @@ core.register_chatcommand("set", {
 			if not setvalue then
 				setvalue = "<not set>"
 			end
-			core.chat_send_player(name, setname.." = "..setvalue)
-			return
+			return true, setname .. " = " .. setvalue
 		end
-		core.chat_send_player(name, "Invalid parameters (see /help set)")
+		return false, "Invalid parameters (see /help set)."
 	end,
 })
 
 core.register_chatcommand("mods", {
 	params = "",
-	description = "lists mods installed on the server",
+	description = "List mods installed on the server",
 	privs = {},
 	func = function(name, param)
-		local response = ""
-		local modnames = core.get_modnames()
-		for i, mod in ipairs(modnames) do
-			response = response .. mod
-			-- Add space if not at the end
-			if i ~= #modnames then
-				response = response .. " "
-			end
-		end
-		core.chat_send_player(name, response)
+		return true, table.concat(core.get_modnames(), ", ")
 	end,
 })
 
 local function handle_give_command(cmd, giver, receiver, stackstring)
-	core.log("action", giver.." invoked "..cmd..', stackstring="'
-			..stackstring..'"')
-	core.log(cmd..' invoked, stackstring="'..stackstring..'"')
+	core.log("action", giver .. " invoked " .. cmd
+			.. ', stackstring="' .. stackstring .. '"')
 	local itemstack = ItemStack(stackstring)
 	if itemstack:is_empty() then
-		core.chat_send_player(giver, 'error: cannot give an empty item')
-		return
+		return false, "Cannot give an empty item"
 	elseif not itemstack:is_known() then
-		core.chat_send_player(giver, 'error: cannot give an unknown item')
-		return
+		return false, "Cannot give an unknown item"
 	end
 	local receiverref = core.get_player_by_name(receiver)
 	if receiverref == nil then
-		core.chat_send_player(giver, receiver..' is not a known player')
-		return
+		return false, receiver .. " is not a known player"
 	end
 	local leftover = receiverref:get_inventory():add_item("main", itemstack)
 	if leftover:is_empty() then
@@ -441,81 +422,79 @@ local function handle_give_command(cmd, giver, receiver, stackstring)
 	-- entered (e.g. big numbers are always interpreted as 2^16-1).
 	stackstring = itemstack:to_string()
 	if giver == receiver then
-		core.chat_send_player(giver, '"'..stackstring
-			..'" '..partiality..'added to inventory.');
+		return true, ("%q %sadded to inventory.")
+				:format(stackstring, partiality)
 	else
-		core.chat_send_player(giver, '"'..stackstring
-			..'" '..partiality..'added to '..receiver..'\'s inventory.');
-		core.chat_send_player(receiver, '"'..stackstring
-			..'" '..partiality..'added to inventory.');
+		core.chat_send_player(receiver, ("%q %sadded to inventory.")
+				:format(stackstring, partiality))
+		return true, ("%q %sadded to %s's inventory.")
+				:format(stackstring, partiality, receiver)
 	end
 end
 
 core.register_chatcommand("give", {
-	params = "<name> <itemstring>",
+	params = "<name> <ItemString>",
 	description = "give item to player",
 	privs = {give=true},
 	func = function(name, param)
 		local toname, itemstring = string.match(param, "^([^ ]+) +(.+)$")
 		if not toname or not itemstring then
-			core.chat_send_player(name, "name and itemstring required")
-			return
+			return false, "Name and ItemString required"
 		end
-		handle_give_command("/give", name, toname, itemstring)
+		return handle_give_command("/give", name, toname, itemstring)
 	end,
 })
+
 core.register_chatcommand("giveme", {
-	params = "<itemstring>",
+	params = "<ItemString>",
 	description = "give item to yourself",
 	privs = {give=true},
 	func = function(name, param)
 		local itemstring = string.match(param, "(.+)$")
 		if not itemstring then
-			core.chat_send_player(name, "itemstring required")
-			return
+			return false, "ItemString required"
 		end
-		handle_give_command("/giveme", name, name, itemstring)
+		return handle_give_command("/giveme", name, name, itemstring)
 	end,
 })
+
 core.register_chatcommand("spawnentity", {
-	params = "<entityname>",
-	description = "spawn entity at your position",
+	params = "<EntityName>",
+	description = "Spawn entity at your position",
 	privs = {give=true, interact=true},
 	func = function(name, param)
 		local entityname = string.match(param, "(.+)$")
 		if not entityname then
-			core.chat_send_player(name, "entityname required")
-			return
+			return false, "EntityName required"
 		end
-		core.log("action", '/spawnentity invoked, entityname="'..entityname..'"')
+		core.log("action", ("/spawnentity invoked, entityname=%q")
+				:format(entityname))
 		local player = core.get_player_by_name(name)
 		if player == nil then
 			core.log("error", "Unable to spawn entity, player is nil")
-			return true -- Handled chat message
+			return false, "Unable to spawn entity, player is nil"
 		end
 		local p = player:getpos()
 		p.y = p.y + 1
 		core.add_entity(p, entityname)
-		core.chat_send_player(name, '"'..entityname
-				..'" spawned.');
+		return true, ("%q spawned."):format(entityname)
 	end,
 })
+
 core.register_chatcommand("pulverize", {
 	params = "",
-	description = "delete item in hand",
-	privs = {},
+	description = "Destroy item in hand",
 	func = function(name, param)
 		local player = core.get_player_by_name(name)
-		if player == nil then
-			core.log("error", "Unable to pulverize, player is nil")
-			return true -- Handled chat message
+		if not player then
+			core.log("error", "Unable to pulverize, no player.")
+			return false, "Unable to pulverize, no player."
 		end
 		if player:get_wielded_item():is_empty() then
-			core.chat_send_player(name, 'Unable to pulverize, no item in hand.')
-		else
-			player:set_wielded_item(nil)
-			core.chat_send_player(name, 'An item was pulverized.')
+			return false, "Unable to pulverize, no item in hand."
 		end
+		player:set_wielded_item(nil)
+		return true, "An item was pulverized."
 	end,
 })
 
@@ -532,8 +511,9 @@ end)
 
 core.register_chatcommand("rollback_check", {
 	params = "[<range>] [<seconds>] [limit]",
-	description = "check who has last touched a node or near it, "..
-			"max. <seconds> ago (default range=0, seconds=86400=24h, limit=5)",
+	description = "Check who has last touched a node or near it,"
+			.. " max. <seconds> ago (default range=0,"
+			.. " seconds=86400=24h, limit=5)",
 	privs = {rollback=true},
 	func = function(name, param)
 		local range, seconds, limit =
@@ -542,20 +522,18 @@ core.register_chatcommand("rollback_check", {
 		seconds = tonumber(seconds) or 86400
 		limit = tonumber(limit) or 5
 		if limit > 100 then
-			core.chat_send_player(name, "That limit is too high!")
-			return
+			return false, "That limit is too high!"
 		end
-		core.chat_send_player(name, "Punch a node (range="..
-				range..", seconds="..seconds.."s, limit="..limit..")")
 
 		core.rollback_punch_callbacks[name] = function(pos, node, puncher)
 			local name = puncher:get_player_name()
-			core.chat_send_player(name, "Checking "..core.pos_to_string(pos).."...")
+			core.chat_send_player(name, "Checking " .. core.pos_to_string(pos) .. "...")
 			local actions = core.rollback_get_node_actions(pos, range, seconds, limit)
 			local num_actions = #actions
 			if num_actions == 0 then
-				core.chat_send_player(name, "Nobody has touched the "..
-						"specified location in "..seconds.." seconds")
+				core.chat_send_player(name, "Nobody has touched"
+						.. " the specified location in "
+						.. seconds .. " seconds")
 				return
 			end
 			local time = os.time()
@@ -571,6 +549,9 @@ core.register_chatcommand("rollback_check", {
 							time - action.time))
 			end
 		end
+
+		return true, "Punch a node (range=" .. range .. ", seconds="
+				.. seconds .. "s, limit=" .. limit .. ")"
 	end,
 })
 
@@ -584,37 +565,35 @@ core.register_chatcommand("rollback", {
 			local player_name = nil
 			player_name, seconds = string.match(param, "([^ ]+) *(%d*)")
 			if not player_name then
-				core.chat_send_player(name, "Invalid parameters. See /help rollback and /help rollback_check")
-				return
+				return false, "Invalid parameters. See /help rollback"
+						.. " and /help rollback_check."
 			end
 			target_name = "player:"..player_name
 		end
 		seconds = tonumber(seconds) or 60
-		core.chat_send_player(name, "Reverting actions of "..
-				target_name.." since "..seconds.." seconds.")
+		core.chat_send_player(name, "Reverting actions of "
+				.. target_name .. " since "
+				.. seconds .. " seconds.")
 		local success, log = core.rollback_revert_actions_by(
 				target_name, seconds)
+		local response = ""
 		if #log > 100 then
-			core.chat_send_player(name, "(log is too long to show)")
+			response = "(log is too long to show)\n"
 		else
 			for _, line in pairs(log) do
-				core.chat_send_player(name, line)
+				response = response .. line .. "\n"
 			end
 		end
-		if success then
-			core.chat_send_player(name, "Reverting actions succeeded.")
-		else
-			core.chat_send_player(name, "Reverting actions FAILED.")
-		end
+		response = response .. "Reverting actions "
+				.. (success and "succeeded." or "FAILED.")
+		return success, response
 	end,
 })
 
 core.register_chatcommand("status", {
-	params = "",
-	description = "print server status line",
-	privs = {},
+	description = "Print server status",
 	func = function(name, param)
-		core.chat_send_player(name, core.get_server_status())
+		return true, core.get_server_status()
 	end,
 })
 
@@ -624,22 +603,19 @@ core.register_chatcommand("time", {
 	privs = {settime=true},
 	func = function(name, param)
 		if param == "" then
-			core.chat_send_player(name, "Missing parameter")
-			return
+			return false, "Missing time."
 		end
 		local newtime = tonumber(param)
 		if newtime == nil then
-			core.chat_send_player(name, "Invalid time")
-		else
-			core.set_timeofday((newtime % 24000) / 24000)
-			core.chat_send_player(name, "Time of day changed.")
-			core.log("action", name .. " sets time " .. newtime)
+			return false, "Invalid time."
 		end
+		core.set_timeofday((newtime % 24000) / 24000)
+		core.log("action", name .. " sets time " .. newtime)
+		return true, "Time of day changed."
 	end,
 })
 
 core.register_chatcommand("shutdown", {
-	params = "",
 	description = "shutdown server",
 	privs = {server=true},
 	func = function(name, param)
@@ -651,24 +627,21 @@ core.register_chatcommand("shutdown", {
 
 core.register_chatcommand("ban", {
 	params = "<name>",
-	description = "ban IP of player",
+	description = "Ban IP of player",
 	privs = {ban=true},
 	func = function(name, param)
 		if param == "" then
-			core.chat_send_player(name, "Ban list: " .. core.get_ban_list())
-			return
+			return true, "Ban list: " .. core.get_ban_list()
 		end
 		if not core.get_player_by_name(param) then
-			core.chat_send_player(name, "No such player")
-			return
+			return false, "No such player."
 		end
 		if not core.ban_player(param) then
-			core.chat_send_player(name, "Failed to ban player")
-		else
-			local desc = core.get_ban_description(param)
-			core.chat_send_player(name, "Banned " .. desc .. ".")
-			core.log("action", name .. " bans " .. desc .. ".")
+			return false, "Failed to ban player."
 		end
+		local desc = core.get_ban_description(param)
+		core.log("action", name .. " bans " .. desc .. ".")
+		return true, "Banned " .. desc .. "."
 	end,
 })
 
@@ -678,11 +651,10 @@ core.register_chatcommand("unban", {
 	privs = {ban=true},
 	func = function(name, param)
 		if not core.unban_player_or_ip(param) then
-			core.chat_send_player(name, "Failed to unban player/IP")
-		else
-			core.chat_send_player(name, "Unbanned " .. param)
-			core.log("action", name .. " unbans " .. param)
+			return false, "Failed to unban player/IP."
 		end
+		core.log("action", name .. " unbans " .. param)
+		return true, "Unbanned " .. param
 	end,
 })
 
@@ -691,28 +663,26 @@ core.register_chatcommand("kick", {
 	description = "kick a player",
 	privs = {kick=true},
 	func = function(name, param)
-		local tokick, reason = string.match(param, "([^ ]+) (.+)")
-		if not tokick then
-			tokick = param
-		end
+		local tokick, reason = param:match("([^ ]+) (.+)")
+		tokick = tokick or param
 		if not core.kick_player(tokick, reason) then
-			core.chat_send_player(name, "Failed to kick player " .. tokick)
-		else
-			core.chat_send_player(name, "kicked " .. tokick)
-			core.log("action", name .. " kicked " .. tokick)
+			return false, "Failed to kick player " .. tokick
 		end
+		core.log("action", name .. " kicked " .. tokick)
+		return true, "Kicked " .. tokick
 	end,
 })
 
 core.register_chatcommand("clearobjects", {
-	params = "",
 	description = "clear all objects in world",
 	privs = {server=true},
 	func = function(name, param)
-		core.log("action", name .. " clears all objects")
-		core.chat_send_all("Clearing all objects.  This may take long.  You may experience a timeout.  (by " .. name .. ")")
+		core.log("action", name .. " clears all objects.")
+		core.chat_send_all("Clearing all objects.  This may take long."
+				.. "  You may experience a timeout.  (by "
+				.. name .. ")")
 		core.clear_objects()
-		core.log("action", "object clearing done")
+		core.log("action", "Object clearing done.")
 		core.chat_send_all("*** Cleared all objects.")
 	end,
 })
@@ -722,17 +692,19 @@ core.register_chatcommand("msg", {
 	description = "Send a private message",
 	privs = {shout=true},
 	func = function(name, param)
-		local found, _, sendto, message = param:find("^([^%s]+)%s(.+)$")
-		if found then
-			if core.get_player_by_name(sendto) then
-				core.log("action", "PM from "..name.." to "..sendto..": "..message)
-				core.chat_send_player(sendto, "PM from "..name..": "..message)
-				core.chat_send_player(name, "Message sent")
-			else
-				core.chat_send_player(name, "The player "..sendto.." is not online")
-			end
-		else
-			core.chat_send_player(name, "Invalid usage, see /help msg")
-		end
+		local sendto, message = param:match("^(%S+)%s(.+)$")
+		if not sendto then
+			return false, "Invalid usage, see /help msg."
+		end
+		if not core.get_player_by_name(sendto) then
+			return false, "The player " .. sendto
+					.. " is not online."
+		end
+		core.log("action", "PM from " .. name .. " to " .. sendto
+				.. ": " .. message)
+		core.chat_send_player(sendto, "PM from " .. name .. ": "
+				.. message)
+		return true, "Message sent."
 	end,
 })
+
diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 803314925..f4e1fd230 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -2543,10 +2543,11 @@ Decoration definition (register_decoration)
 
 Chatcommand definition (register_chatcommand)
 {
-    params = "<name> <privilege>", -- short parameter description
-    description = "Remove privilege from player", -- full description
-    privs = {privs=true}, -- require the "privs" privilege to run
-    func = function(name, param), -- called when command is run
+    params = "<name> <privilege>", -- Short parameter description
+    description = "Remove privilege from player", -- Full description
+    privs = {privs=true}, -- Require the "privs" privilege to run
+    func = function(name, param), -- Called when command is run.
+                                  -- Returns boolean success and text output.
 }
 
 Detached inventory callbacks