MCJS

Execute JavaScript code in Minecraft

Introduction

This project has added the /js directive to execute JavaScript code. Example:

/js let a="Hello";runCommand("/say "+a)
runCommand("command") // execute command

// Syntax of version 1.0
registerCommand('hi', function(name) {
 return 'Hello, ' + name + '!'! ';
}); // Register directive

// Syntax of version 1.1
registerCommand('hi', OP等级, function(name) {
 return 'Hello, ' + name + '!'! ';
}); // Register directives

// Syntax of version 1.2 (with new parameter support)
registerCommand('hi', OP_Level, function(name, arg1, customname) {
 return 'Hello, ' + name + '! The input parameters are: ' + arg1 + customname;
}); // Register command, supports receiving command parameters

/js set <key> <value> // Set configuration option
/js reset// Reset all configurations to their default values
/js list// Display registered commands

Permission Level Description

Level	Applicable to
0	All players
1	Basic administrator
2	Ordinary OP
3	Senior administrator
4	Server Owner

API List

// File operations
saveFile(path, content) // Save the file
saveBinaryFile(path, content) // Save binary file
loadFile(path) // Load the file

// Configuration management
setOption(key, value) // Set configuration
getOption(key) // Get configuration
resetOptions() // Reset configuration

// Command registration
registerCommand(name, permissionlevel, fn)

// Command execution
runCommand(command)

Requires OP permission at level 2 (server administrator / local save for enabling commands / command block) to use.

The execution log will be saved in the js_execution.log file.

Precautions

Scripts can execute any command, so please refrain from running scripts on the server indiscriminately.

Configuration

Use /js set config_item value to make settings.

Configuration Item	Default Value	Description
infoDisplay	true	Whether to display the execution success prompt
errDisplay	true	Whether to display error messages
customCommandInfo	true	Whether to display the execution result of the custom command
codeLenLimit	10000	Maximum length limit of script (characters)
codeTimeLimit	5000	Script execution timeout (milliseconds)
currentCodeLimit	1	Limit on the number of scripts executed simultaneously
logExecution	true	Whether to log execution details
allowBinaryFiles	true	Whether to allow binary file operations
maxFileSize	10MB	Maximum file loading size

Experimental Features

saveFile('filename', 'content') saves a file

loadFile('filename') loads a file (updated in version 1.1: binary files return Base64)

saveBinaryFile(path, content) saves a binary file

Update Log

1.0

• Initial version
• Add /js <script> to execute JavaScript
• Add registerCommand(name, fn) to register a command
• Add runCommand(command) to execute commands

1.1

• Added /js set
• Command execution permission setting (registerCommand(name, level, fn))
• The issue of unknown crashes has been fixed
• Optimization of document management system
• Removed "Him"

1.2

• Custom command supports receiving parameters: The callback function signature in registerCommand(name, level, fn) is extended to fn(name, arg1, customname)
• name: The name of the player who executed the command
• arg1: The first argument of the command (an empty string if there is no argument)
• customname: The remaining command parameters (with original spaces retained; empty string if no parameters)
• Persistent dynamic commands: All commands registered through registerCommand will be automatically saved to config/mcjs/registercommands.js
• The server will automatically recover after rebooting, without the need to re-execute the script
• The file is automatically maintained by the mod; please exercise caution when editing manually
• New /js list enhancement: Displays a list of registered commands, including those restored from persistence

1.2 Command Examples

/js registerCommand('hi', 2, function(name, arg1, customname) {
 return 'Hello, ' + name + '! The input parameters are: ' + arg1 + customname;
});

Input	Output
/hi	Hello, Steve! The input parameters are:
/hi test	Hello, Steve! The input parameter is: test
/hi test	ditto (extra spaces are ignored as separators)
/hi test test2	Hello, Steve! The input parameter is: testtest2

Example content of the persistent file config/mcjs/registercommands.js:

// MCJS persistent command registration file. Automatically maintained by the mod, please exercise caution when editing manually.
registerCommand('hi', 2, function(name, arg1, customname) { return '你好，' + name + '！，输入的参数为：' + arg1 + customname;  });

1.2 Precautions

• The function body cannot reference external closure variables, otherwise they will be lost after persistent restoration - registercommands.js only saves the function definition itself.
• Do not repeatedly execute the same registerCommand('same_name', ...). Brigadier will throw an exception for duplicate literals; to overwrite, please restart the server or manually clean up.
• Chinese messy code issue: Before compiling via the Windows command line, you can first run chcp 65001, which will not affect the actual compilation results.
• The permission level is determined by the second parameter of registerCommand, and defaults to 2 if not specified.

1.2 API Changes

// 1.1 and earlier versions
registerCommand(name, permissionlevel, fn)
// fn parameter: function(name) { ... }

// Starting from 1.2
registerCommand(name, permissionlevel, fn)
// fn parameter: function(name, arg1, customname) { ... }
// Compatible with old function(name) { ... }

MCJS

在 Minecraft 里执行 JavaScript 代码

简介

这个项目添加了 /js 指令来执行 JavaScript 代码。示例：

/js let a="Hello";runCommand("/say "+a)
runCommand("指令") // 执行指令

// 1.0 版本语法
registerCommand('hi', function(name) {
  return '你好，' + name + '！';
}); // 注册指令

// 1.1 版本语法
registerCommand('hi', OP等级, function(name) {
  return '你好，' + name + '！';
}); // 注册指令

// 1.2 版本语法（新增参数支持）
registerCommand('hi', OP等级, function(name, arg1, customname) {
  return '你好，' + name + '！，输入的参数为：' + arg1 + customname;
}); // 注册指令，支持接收命令参数

/js set <key> <value>// 设置配置选项
/js reset// 重置所有配置到默认值
/js list// 显示已注册命令

权限等级说明

等级	适用对象
0	所有玩家
1	基础管理员
2	普通 OP
3	高级管理员
4	服主

API 列表

// 文件操作
saveFile(path, content)        // 保存文件
saveBinaryFile(path, content)  // 保存二进制文件
loadFile(path)                 // 加载文件

// 配置管理
setOption(key, value)          // 设置配置
getOption(key)                 // 获取配置
resetOptions()                 // 重置配置

// 命令注册
registerCommand(name, permissionlevel, fn)

// 命令执行
runCommand(command)

使用需要 level 2 的 OP 权限（服务器管理员 / 开启命令的本地存档 / 命令方块）。

执行日志会保存在 js_execution.log 文件。

注意事项

脚本可以执行一切指令，不要在服务器上乱跑脚本。

配置

使用 /js set 配置项 值 来进行设置。

配置项	默认值	说明
infoDisplay	true	是否显示执行成功提示
errDisplay	true	是否显示错误信息
customCommandInfo	true	自定义命令是否显示执行结果
codeLenLimit	10000	脚本最大长度限制（字符）
codeTimeLimit	5000	脚本执行超时时间（毫秒）
currentCodeLimit	1	同时执行的脚本数量限制
logExecution	true	是否记录执行日志
allowBinaryFiles	true	是否允许二进制文件操作
maxFileSize	10MB	最大文件加载大小

实验性功能

saveFile('文件名', '内容') 保存文件

loadFile('文件名') 加载文件（1.1 版本更新：二进制文件返回 Base64）

saveBinaryFile(path, content) 保存二进制文件

更新日志

1.0

• 初始版本
• 添加 /js <脚本> 执行 JavaScript
• 添加 registerCommand(name, fn) 注册指令
• 添加 runCommand(command) 执行指令

1.1

• 新增 /js set
• 命令执行权限设置（registerCommand(name, level, fn)）
• 不知名闪退已修复
• 文件管理系统优化
• 移除了 Him

1.2

• 自定义命令支持接收参数：registerCommand(name, level, fn) 中的回调函数签名扩展为 fn(name, arg1, customname)
  • name：执行命令的玩家名
  • arg1：命令的第一个参数（无参数时为空字符串）
  • customname：命令剩余参数（保留原始空格，无参数时为空字符串）
• 动态命令持久化：所有通过 registerCommand 注册的命令会自动保存到 config/mcjs/registercommands.js
  • 服务器重启后自动恢复，无需重新执行脚本
  • 文件由 mod 自动维护，手动编辑请谨慎
• 新增 /js list 增强：显示已注册命令列表，含持久化恢复的命令

1.2 命令示例

/js registerCommand('hi', 2, function(name, arg1, customname) {
  return '你好，' + name + '！，输入的参数为：' + arg1 + customname;
});

输入	输出
/hi	你好，Steve！，输入的参数为：
/hi test	你好，Steve！，输入的参数为：test
/hi test	同上（多余空格被忽略作为分隔）
/hi test test2	你好，Steve！，输入的参数为：testtest2

持久化文件 config/mcjs/registercommands.js 内容示例：

// MCJS 持久化命令注册文件。由 mod 自动维护，手动编辑请谨慎。
registerCommand('hi', 2, function(name, arg1, customname) { return '你好，' + name + '！，输入的参数为：' + arg1 + customname; });

1.2 注意事项

• 函数体不能引用外部闭包变量，否则持久化恢复后会丢失——registercommands.js 只保存函数定义本身。
• 不要重复执行同一个 registerCommand('同名', ...)，Brigadier 会对重复 literal 抛异常；如需覆盖请重启服务器或手动清理。
• 中文乱码问题：Windows 命令行编译前可先 chcp 65001，不影响实际编译结果。
• 权限等级以 registerCommand 第二个参数为准，未填时默认 2。

1.2 API 变更

// 1.1 及以前
registerCommand(name, permissionlevel, fn)
// fn 参数：function(name) { ... }

// 1.2 起
registerCommand(name, permissionlevel, fn)
// fn 参数：function(name, arg1, customname) { ... }
// 兼容旧的 function(name) { ... }