Lua 5.0文档对诸如_LOADED，LUA_PATH，_ALERT等(在Lua 5.1中无法使用)之类的东西感到困惑，我发现所有这些东西都已被删除，并将功能放在其他地方。我是否认为Lua 5.1中剩下的唯一一个全局变量是" _VERSION"？

解决方案

文档似乎认为几乎是这种情况。

_G
      A global variable (not a function) that holds the global environment
  (that is, _G._G = _G). Lua itself does
  not use this variable; changing its
  value does not affect any environment,
  nor vice-versa. (Use setfenv to change
  environments.)

看起来还有_PROMPT和_PROMPT2，但仅当以交互方式使用独立lua时：

If the global variable _PROMPT
  contains a string, then its value is
  used as the prompt. Similarly, if the
  global variable _PROMPT2 contains a
  string, its value is used as the
  secondary prompt (issued during
  incomplete statements). Therefore,
  both prompts can be changed directly
  on the command line or in any Lua
  programs by assigning to _PROMPT.

假设我们没有打开任何库，也有_G，pairs，ipairs和newproxy`。