Global variable dumping script for Dual Universe. See https://board.dualthegame.com/index.php?/topic/20052-lua-all-global-variables/ for more info. License: WTFPL

dump.lua

local max = math.max
local concat, insert = table.concat, table.insert
local byte, gsub, format, match, rep = string.byte, string.gsub, string.format, string.match, string.rep

local buffer = { "Lua globals dump: \r\n\r\n" }

local should_get_function_params = true
local should_dump_functions = false

local table_visited = {}

local indentChange = "  "

local function_names_to_call = {
  "^g$",
  "^get",
  "^is",
  "^gravity",
  "^distance",
  "^world",
  "^local",
  "Axis$",
  "Direction$"
}

local string_names_to_hide = { -- these may contain personally-identifiable information or system configuration details
  "^path",
  "^cpath"
}

---@param timeToSleepInSeconds number
local function sleep (timeToSleepInSeconds)
  if not coroutine.isyieldable() then
    error("sleep called from outside a coroutine!")
  end

  local wakeUpTime = system.getTime() + timeToSleepInSeconds
  while system.getTime() < wakeUpTime do coroutine.yield() end
end

---@param str any
---@param patterns string[]
local function matches_any_pattern (str, patterns)
  str = tostring(str)

  for _, pattern in ipairs(patterns) do
    if str:find(pattern) then return true end
  end

  return false
end

---@param name any
local function should_call_function (name)
  return matches_any_pattern(name, function_names_to_call)
end

---@param name any
local function should_hide_string (name)
  return matches_any_pattern(name, string_names_to_hide)
end

---@param tbl table
local function get_sorted_keys (tbl)
  local keys = {}

  for key in pairs(tbl) do
    keys[#keys + 1] = key
  end

  table.sort(keys, function (key1, key2)
    return tostring(key1) < tostring(key2)
  end)

  return keys
end

---@param str string
local function escape_string (str)
  str = format("%q", str):gsub("\\\n", "\\n")

  local chr
  repeat
    chr = match(str, "[^%g ]")

    if chr then
      str = gsub(str, chr, format("\\x%02x", byte(chr)))
    end
  until chr == nil

  return str
end

---@param fn_name string
---@param fn function
local function get_function_params (fn_name, fn)
  -- By default, load() uses the string chunk itself as the chunk name,
  -- and the chunk name may be included in debug information.
  -- This may allow getting names and count of parameters from some functions.

  local dump_success, dump_result = pcall(string.dump, fn)
  if not dump_success then return nil end

  local params = match(dump_result, "function%s+[^%s)]*" .. fn_name .. "%s*%(([^)]*)%)")
  if not params then return nil end

  params = params:gsub(",%s+", ",") -- remove whitespace after function parameter names
  return params
end

---@param value any
local function better_tostring (value)
  if type(value) == "string" then
    return "string: " .. escape_string(value)
  elseif type(value) == "number" then
    return "number: " .. value
  elseif type(value) == "boolean" then
    return "boolean: " .. tostring(value)
  else
    return tostring(value)
  end
end

---@param key any
---@param value any
---@param indent string|nil
local function dump_value (key, value, indent)
  indent = indent and (indent .. indentChange) or ""

  local key_column = indent .. tostring(key)
  local value_column = better_tostring(value)

  if type(value) == "string" and should_hide_string(key) then
    value_column = "string: <hidden by the dumping script>"
  end
  if type(value) == "function" and should_get_function_params then
    local fn_params = get_function_params(key, value)
    if fn_params then
      key_column = key_column .. "(" .. fn_params .. ")"
    end
  end

  local column_separator = rep(' ', max(2, 50 - #key_column))

  insert(buffer, key_column .. column_separator .. value_column .. "\r\n")

  if type(value) == "table" then
    if table_visited[value] then
      insert(buffer, indent .. indentChange .. "[see above]" .. "\r\n")
    else
      table_visited[value] = true

      local metatable = getmetatable(value)
      if metatable then
        dump_value("[metatable]", metatable, indent)
      end

      local sorted_keys = get_sorted_keys(value)
      for _, sorted_key in ipairs(sorted_keys) do
        dump_value(sorted_key, value[sorted_key], indent)
      end

      coroutine.yield()
    end
  end

  if type(value) == "function" and should_dump_functions then
    local dump_success, dump_result = pcall(string.dump, value)
    if dump_success and dump_result then
      dump_value('[dump]', dump_result, indent)
    end
  end

  if type(value) == "function" and should_call_function(key) then
    local pcall_result = { pcall(value) }
    dump_value("[pcall]", pcall_result, indent)
  end
end

if not system then
  -- prepare a dummy object to test this script
  -- luacheck: ignore meaning_of_life
  meaning_of_life = {
    get_answer = function () return 42 end,
    get_question = function () error("Giant computer not available") end
  }

  setmetatable(meaning_of_life, {})
end

dumping_coroutine = coroutine.create(function ()
  if screen then
    screen.setCenteredText("Please wait...")
  end

  if system then
    -- wait for element widget data to be populated
    sleep(5)
  end

  dump_value("_G", _G)
  dump_value("_ENV", _ENV)

  local output = concat(buffer)

  if screen then
    screen.clear()
    screen.setCenteredText("Done!")
  end

  if system then
    system.logInfo(output)
    unit.exit()
  else
    print(output)
  end
end)

if not system then
  while coroutine.resume(dumping_coroutine) do end
end

-- Add a system update() event handler:
-- coroutine.resume(dumping_coroutine)