[文本处理] 批处理怎样截取文本倒数第三行的内容？

jwwlchen

有一系列.txt文本文件，行数不固定，怎么把每个文件的倒数第三行内容导出到一个文件中?

batman

@echo off&setlocal enabledelayedexpansion
(for %%a in (*.txt) do (
   for /f "usebackq delims=" %%b in ("%%a") do (
     set "str2=!str1!"
     set "str1=!str!"
     set "str=%%a"
   )
  if defined str2 echo,!str2!&set "str2="
))>new.txt
start new.txt
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batman

附取文本倒数第N行的两种方法：
1、

@echo off&setlocal enabledelayedexpansion
(for /l %%a in (1,1,100) do echo %%a)>a.txt
set /a n=!random!%%100+1
for /f "delims=" %%a in (a.txt) do (
  for /l %%b in (%n%,-1,1) do (
    if %%b neq 1 (
      set /a a=%%b-1
      for %%c in (!a!) do set "str%%b=!str%%c!"
      ) else (
      set "str%%b=%%a" 
    )
  )
)
echo 取得a.txt倒数第%n%行的值为：!str%n%!
pause>nul
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2、

@echo off&setlocal enabledelayedexpansion
(for /l %%a in (1,1,100) do echo %%a)>a.txt
for /f "delims=" %%a in (a.txt) do set /a m+=1&set "_!m!=%%a"
set /a n=!random!%%100+1,m-=n-1
echo 取得a.txt倒数第%n%行的值为：!_%m%!
pause>nul
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BAT-VBS

@echo off
set n=0
for /f %%a in (a.txt) do (
    set /a n+=1
)
echo %n%
set /a n-=3
call :getLine %n%
pause
goto :eof

:getLine
for /f "skip=%1 delims=" %%a in (a.txt) do (
    echo,%%a
    goto :eof
)
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terse

@echo off&setlocal enabledelayedexpansion
for /f "delims=" %%i in ('dir /b /a-d *.TXT') do (
    sort /+8192 "%%i"|more +2 >_ten.t
    set /pstr=<_ten.t
    >>_temp.txt echo;!str!
)
del _ten.t&pause
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