Commands

MinecraftConsoles has a command system based on the 4J Studios console edition architecture. Commands use a binary packet-based dispatch instead of the text-parsing approach from Java Edition.

Command architecture

Base class: Command

File: Minecraft.World/Command.h, .cpp

All commands extend the abstract Command class.

class Command
{
public:
    virtual EGameCommand getId() = 0;
    virtual int getPermissionLevel();
    virtual void execute(shared_ptr<CommandSender> source, byteArray commandData) = 0;
    virtual bool canExecute(shared_ptr<CommandSender> source);

    static void logAdminAction(...);
};

Permission levels:

Level	Constant	Examples
0	LEVEL_ALL	help, emote
1	LEVEL_MODERATORS	mute
2	LEVEL_GAMEMASTERS	seed, tp, give
3	LEVEL_ADMINS	whitelist, ban
4	LEVEL_OWNERS	stop, save-all

Unlike Java Edition, commands receive byteArray commandData (a binary packet) instead of parsed string arguments. The default getPermissionLevel() returns LEVEL_GAMEMASTERS (2).

Admin logging

Two static logAdminAction() overloads handle command logging:

• logAdminAction(source, messageType, message, customData, additionalMessage) for standard logging
• logAdminAction(source, type, messageType, message, customData, additionalMessage) with an extra type parameter

These use ChatPacket::EChatPacketMessage for message categorization. A static AdminLogCommand *logger pointer is set via setLogger().

Protected helper

getPlayer(PlayerUID) returns a shared_ptr<ServerPlayer> for a given player UID, used by commands that target specific players.

CommandDispatcher

File: Minecraft.World/CommandDispatcher.h, .cpp

Routes commands by their EGameCommand enum value.

class CommandDispatcher
{
    unordered_map<EGameCommand, Command*> commandsById;
    unordered_set<Command*> commands;

public:
    int performCommand(shared_ptr<CommandSender> sender, EGameCommand command, byteArray commandData);
    Command *addCommand(Command *command);
};

performCommand() checks canExecute() before running. If the sender doesn’t have permission, a red “You do not have permission” message is shown (except in content packages). Returns an integer status code.

addCommand() registers a command and returns it for chaining.

EGameCommand enum

File: Minecraft.World/CommandsEnum.h

enum EGameCommand
{
    eGameCommand_DefaultGameMode,
    eGameCommand_Effect,
    eGameCommand_EnchantItem,
    eGameCommand_Experience,
    eGameCommand_GameMode,
    eGameCommand_Give,
    eGameCommand_Kill,
    eGameCommand_Time,
    eGameCommand_ToggleDownfall,
    eGameCommand_Teleport,
    eGameCommand_COUNT
};

The eGameCommand_COUNT value is 10, meaning there are 10 registered command types.

CommandSender

File: Minecraft.World/CommandSender.h

The interface for anything that can send commands:

• sendMessage(wstring message, EChatPacketMessage type, int customData, wstring additionalMessage) sends feedback
• hasPermission(EGameCommand command) checks if the sender can use a command

CommandBlockEntity implements this interface directly.

Implemented commands (C++)

These commands have native C++ implementations that are fully functional:

GameModeCommand

File: Minecraft.World/GameModeCommand.h, .cpp

Changes a player’s game mode. Permission level: LEVEL_GAMEMASTERS. Command ID: eGameCommand_GameMode.

Includes getModeForString() to parse the mode argument from the binary packet.

DefaultGameModeCommand

File: Minecraft.World/DefaultGameModeCommand.h, .cpp

Sets the server’s default game mode. Extends GameModeCommand. Command ID: eGameCommand_DefaultGameMode. Permission level: LEVEL_GAMEMASTERS.

GiveItemCommand

File: Minecraft.World/GiveItemCommand.h, .cpp

Gives items to players. Permission level: LEVEL_GAMEMASTERS. Command ID: eGameCommand_Give.

Has a static preparePacket() helper that builds a GameCommandPacket with item ID, amount, aux value, and optional NBT tag string.

KillCommand

File: Minecraft.World/KillCommand.h, .cpp

Kills the command sender. Permission level: LEVEL_GAMEMASTERS. Command ID: eGameCommand_Kill.

TimeCommand

File: Minecraft.World/TimeCommand.h, .cpp

Sets or adds to the world time. Permission level: LEVEL_GAMEMASTERS. Command ID: eGameCommand_Time.

Methods: doSetTime() and doAddTime(). Has a static preparePacket() for toggling day/night via a packet.

ToggleDownfallCommand

File: Minecraft.World/ToggleDownfallCommand.h, .cpp

Toggles weather. Permission level: LEVEL_GAMEMASTERS. Command ID: eGameCommand_ToggleDownfall.

EnchantItemCommand

File: Minecraft.World/EnchantItemCommand.h, .cpp

Enchants a player’s held item. Permission level: LEVEL_GAMEMASTERS. Command ID: eGameCommand_EnchantItem.

Has a static preparePacket() that takes enchantment ID and level (default 1).

ExperienceCommand

File: Minecraft.World/ExperienceCommand.h, .cpp

Grants experience to a player. Permission level: LEVEL_GAMEMASTERS. Command ID: eGameCommand_Experience.

TeleportCommand

File: Minecraft.Client/TeleportCommand.h, .cpp

Teleports players. Lives in Minecraft.Client rather than Minecraft.World, which is unusual. Command ID: eGameCommand_Teleport.

EffectCommand

File: Minecraft.World/EffectCommand.h, .cpp

Applies or removes status effects from players. Permission level: LEVEL_GAMEMASTERS. Command ID: eGameCommand_Effect.

Stub implementation

The execute() method body is entirely commented out in the current source. The Java-style pseudocode in the comments shows the intended behavior: parse player name, effect ID, duration, and amplifier; apply or clear effects. The command is registered but does nothing when called.

Java reference commands (commented out)

Several command files have complete Java source code in block comments. These are reference implementations that haven’t been ported to C++ yet. They exist only as #if 0 blocks or Java code in comments.

GameDifficultyCommand

File: Minecraft.World/GameDifficultyCommand.h

Sets the server difficulty. Accepts peaceful/p, easy/e, normal/n, hard/h, or numeric 0-3. Tab-completion supported. Default permission level 2.

GameRuleCommand

File: Minecraft.World/GameRuleCommand.h

Gets, sets, or lists game rules. With 0 args it lists all rules, with 1 arg it shows a rule value, with 2 args it sets a rule. Tab-completes rule names and true/false values. Default permission level 2.

ShowSeedCommand

File: Minecraft.World/ShowSeedCommand.h

Displays the world seed. Allows execution in singleplayer regardless of permission level (overrides canExecute()). Default permission level 2.

WeatherCommand

File: Minecraft.World/WeatherCommand.h

Sets weather to clear, rain, or thunder with an optional duration in seconds. Default duration is 300 to 600 seconds (randomly chosen). Tab-completes weather type names. Default permission level 2.

PlaySoundCommand

File: Minecraft.World/PlaySoundCommand.h

Plays a sound at a location for a specific player. Supports position, volume, pitch, and minimum volume arguments. Handles the case where the player is too far away by either sending the sound at reduced volume from a closer position or throwing an error. Default permission level 2.

SpreadPlayersCommand

File: Minecraft.World/SpreadPlayersCommand.h

Spreads players randomly across an area. Has a MAX_ITERATION_COUNT of 10,000 for the randomization algorithm. Default permission level 2.

SetPlayerTimeoutCommand

File: Minecraft.World/SetPlayerTimeoutCommand.h

Sets the connection timeout for a player.

AdminLogCommand

File: Minecraft.World/AdminLogCommand.h

The logging backend used by Command::logAdminAction().

GameRules

File: Minecraft.World/GameRules.h, .cpp

While the GameRuleCommand itself isn’t ported, the GameRules class is implemented in C++. It stores game rules as typed values.

The inner GameRule class stores each rule as a wstring with cached bool, int, and double conversions.

Defined rules (4J converted from strings to integer constants):

Rule constant	Purpose
RULE_DOFIRETICK	Fire spread
RULE_MOBGRIEFING	Mob block destruction
RULE_KEEPINVENTORY	Keep items on death
RULE_DOMOBSPAWNING	Mob spawning
RULE_DOMOBLOOT	Mob item drops
RULE_DOTILEDROPS	Block item drops
RULE_COMMANDBLOCKOUTPUT	Command block output to chat
RULE_NATURAL_REGENERATION	Natural health regeneration
RULE_DAYLIGHT	Daylight cycle

getBoolean(int rule) is the main query method.

EntitySelector

File: Minecraft.World/EntitySelector.h, .cpp

Used throughout the command and entity systems for filtering entities.

class EntitySelector
{
public:
    static const EntitySelector *ENTITY_STILL_ALIVE;
    static const EntitySelector *CONTAINER_ENTITY_SELECTOR;
    virtual bool matches(shared_ptr<Entity> entity) const = 0;
};

Built-in selectors:

Class	File	Purpose
AliveEntitySelector	EntitySelector.cpp	Matches entities that are still alive
ContainerEntitySelector	EntitySelector.cpp	Matches entities that are containers
MobCanWearArmourEntitySelector	EntitySelector.cpp	Matches mobs that can wear a specific armor item
HorseEntitySelector	EntityHorse.h	Matches horse entities (for breeding)
LivingEntitySelector	WitherBoss.h	Matches living entities (for Wither targeting)

The two static singleton instances (ENTITY_STILL_ALIVE, CONTAINER_ENTITY_SELECTOR) are used throughout the codebase for common filtering operations.

Note

This is not the @a/@p/@r/@e target selector system from Java Edition. The console edition uses a different packet-based player selection mechanism through its UI-driven command system.

Comparison with LCEMP

LCEMP has 9 of the 10 implemented commands. The shared commands are: /gamemode, /give, /kill, /time, /toggledownfall, /tp, /enchant, /xp, and /defaultgamemode. LCEMP has matching implementations for all of these (e.g. EnchantItemCommand.h/cpp with eGameCommand_EnchantItem, ExperienceCommand.h/cpp with eGameCommand_Experience, DefaultGameModeCommand.h/cpp with eGameCommand_DefaultGameMode).

The only implemented command in MinecraftConsoles but not in LCEMP is:

• /effect (stub, execute body is commented out)

All the Java-reference commands (difficulty, gamerule, seed, weather, playsound, spreadplayers) are also MC-only.

MinecraftConsoles also adds the GameRules system, CommandBlock / CommandBlockEntity, and the EntitySelector system, none of which exist in LCEMP.

Dedicated Server Commands

LCEMP also has a completely separate text-based command system in the Minecraft.Server/ module for the standalone dedicated server. This system uses ServerCommand and ConsoleCommandDispatcher instead of the binary packet-based Command and CommandDispatcher from Minecraft.World. The dedicated server has 27 commands typed into the server console (stop, tp, time, give, kick, ban, whitelist, etc.).

These two command systems overlap in functionality but are entirely separate implementations. See the Dedicated Server page for the full command list and architecture.