中国DOS联盟

@echo off
:select
set select=2
cls&set /p select=是否调用b.txt更改，默认回车为不调用？(1.yes 2.no)
if "%select%"=="1" goto change
if "%select%"=="2" goto run
echo 请正确选择&ping /2 127.1>nul&goto select
:change
set /p m=<b.txt
for /f "delims=" %%i in ('type %~nx0') do (
     set str=%%i
     setlocal enabledelayedexpansion
     set str=!str:3=%m%!
     echo.!str!>>temp.bat
     endlocal
)
del /q %~nx0 ren temp.bat %~nx0
:run
echo 1234567
pause>nul