terse

@echo off
set "ture="
(for /f "delims=" %%i in (x.txt) do (
      if defined ture (
         if  defined _%%i  (
              if not defined #%%i echo;%%i&set #%%i=a
         ) else echo;%%i
      ) else echo;%%i&set _%%i=a
      if "%%i" == "===="  set "ture=a"
))>2.txt
pause
复制代码