WHY

@echo off
setlocal enabledelayedexpansion
REM 删除第1行，倒数第1行

for /f "skip=1 delims=" %%i in ('dir /b /a-d *.pdf') do (
    if defined file echo;del "!file!"
    set "file=%%i"
)
pause
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@echo off
setlocal enabledelayedexpansion
REM 删除第1/3/5行，倒数第1/3/5行

for /f %%i in ('dir /b *.pdf ^| find /c /v ""') do (
    set /a n=%%i+1, n1=n-1, n3=n-3, n5=n-5
)
for %%i in (1,3,5,!n1!,!n3!,!n5!) do set _%%i=1

for /f "delims=" %%i in ('dir /b *.pdf') do (
    set /a i+=1
    if not defined _!i! echo;del "%%i"
)
pause
复制代码