中国DOS联盟

@echo off

echo 我爱你>>a.txt

@echo off

type nul>c.txt

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

  if defined _%%a (

    >>c.txt echo.%%a

  )

  set "_%%a=%%a"

)

findstr /g:c.txt b.txt|sort>bb.txt

Originally posted by HAT at 2008-11-18 14:31:
a.txt的最后一行非空的话：

@echo off

echo 我爱你>>a.txt

@echo off

type nul>b.txt

for /f %%a in ('type a.txt^|find /c /v ""') do (

  set "RowNum=%%a"

)

for /f "tokens=1* delims=:" %%a in ('findstr /n .* a.txt') do (

  if %%a lss %RowNum% (

    >>b.txt echo.%%b

  ) else (

    >>b.txt echo.%%b我爱你

  )

)

move /y b.txt a.txt