中国DOS联盟

@echo off

setlocal enabledelayedexpansion

>b.txt type nul

set count=0

for /f "delims=" %%a in (a.txt) do (

  set /a count+=1

  if !count! lss 7 (

    >>b.txt echo %%a

  )

)

move /y b.txt a.txt

@echo off

setlocal enabledelayedexpansion

for /f "delims=" %%a in (1.txt) do (

   set "var=%%a"

   if not "!var:~,3!"==""4"" (echo !var!) else (goto :out)

)

:out

pause

@echo off

more +6 a.txt>b.txt

findstr /b /e /v /g:b.txt a.txt>c.txt

move /y c.txt a.txt

del /q b.txt