local format = os.selfname -- or os.selfcore, I couldn't find a difference yet
local ourname = arg[0] -- This might not be os.selfarg[0]
-- We want to drop arg[0] aka. ourname from the arguments to avoid recursion
if os.selfarg[0] == ourname then
  ourname = nil
end
local run
for i, a in ipairs(os.selfarg) do
  if a == ourname then -- Avoid recursion
    table.remove(os.selfarg, i)
    ourname = nil
    a = os.selfarg[i]
  end
  if a == "--" then break end -- This convention is not respected by luametatex itself
  -- LuaMetaTeX needs -- to introduce parameters,
  -- but fmtutil uses just -. Let's rewrite this on the fly:
  a = a:gsub("^%-%-?", "--")
  os.selfarg[i] = a
  if a:sub(1, 11) == "--progname=" then
    format = a:sub(12)
  end
  if a:sub(1, 6) == "--run=" then
    run = true
  end
end
os.setenv("engine", status.luatex_engine)
local kpse_call = io.popen(string.format("kpsewhich -progname %s -format lua -all -must-exist %s-init.lua", format, format))
local file
repeat
  file = kpse_call:read()
until not file:match('^%.')
if not kpse_call:close() then
  error(file)
end

local geterrorcode
if os.type == 'windows' then
  function geterrorcode(ec) return ec end
else
  function geterrorcode(ec) return ec & 0xFF == 0 and ec >> 8 or 0xFF end
end

local args = os.selfarg[1] and " \"" .. table.concat(os.selfarg, "\" \"") .. "\"" or ""
if run then -- The user wants to take care of it
  os.exit(geterrorcode(os.execute(string.format("luametatex \"--lua=%s\" --arg0=\"%s\"%s", file, os.selfarg[0], args))))
else
  for i = 1, 5 do
    local status = geterrorcode(os.execute(string.format("luametatex \"--lua=%s\" --arg0=\"%s\" --run=%i%s", file, os.selfarg[0], i, args)))
    if status ~= 75 then
      os.exit(status)
    end
  end
  os.exit(75)
end