batch-file - MS-Win-CMD PushD/PopD 如何工作以及为什么不在 "For/f"-Loop 中

Question

在我一次又一次找不到答案后，我编写了这些脚本:

<!-- : first Line of "JustPopdBack.cmd"-Script (a CMD+Script for Windows)
@echo off %debug%
setLocal enableExtensions

::    Copyleft 2017 Markus Merkle (aka Mäx) - Licence: GNU-GPLv3
::  ----------------------------------------------------------------------------
::  Cause it seems stupid to make a short Script long just for Right
::  of the Author, so the Licence-Text is not embeded in this Script.
::  !!! Please have a look on <http://www.gnu.org/licenses/>
::      if you still don't know the GNU-GPLv3.
::  ----------------------------------------------------------------------------
::   This is just a free and open TestScript
::   Feel free to used or modify but please mark this work (how as done).
:: -----------------------------------------------------------------------------
 title JustPopdBack-Test
 color 0a                                 %= cause I like LightGreen on Black =%
 echo.
 echo. Just a Test-Script for PushD and PopD Command
 echo.
 echo. To use it please Enter some Directorys first
 echo. Don't shy to use diffrent Drives (C:\ or D:\ etc. )
 echo. ...and feel free to use the TAB-Key then...
 echo. Lets PushD in this Dir and after just Enter Nothing Popd out.
::******************************************************************************
 :dLoop for UserQuest and Pushd in
 echo.
 set "NxtDir="
 set /P "NxtDir=NextDir? :\> "
 if defined NxtDir (PushD %NxtDir% & goTo dLoop)
::------------------------------------------------------------------------------
 echo.
 echo. Lets see the PushD History
 pushD
 echo. now try again with "For /F"-Loop a PopD Back.
 for /f %%a in ('pushD') do (echo %%a && PopD)
 echo.
 echo This don't work - did you know why?
 timeOut -1
:*******************************************************************************
 :PopDback that will work
 PopD && Echo. Uh I PopD'd - let's'ee PushD now: && PushD && goTo PopDback
 :: but I don't like that - can you help to make me happy ?
 --------------------------------------------------------------------------------
 timeout -1
 color
 exit /b                                        %= That the End of this Script =%
 ::       Thnx to all my Teachers 
 ::    ...but the realy ones not the called & most have just 60 Minutes for me...

我希望你明白我为什么写这个脚本，也希望大家给我很多评论，这样我们就可以找出这里或那里出了什么问题......(嘿，不在我的脑海中 - 我希望:-)

我这篇文章的目标是一个作品

for /f %a in ('PushD') do PopD

Answer 1

for/F 在新的 cmd.exe 上下文中启动命令。
因此，pushd 会在那里执行，然后上下文将被关闭。
新cmd.exe中的pushd根本不影响父上下文。
因此 popd 不会恢复 Pushd。

如果你只想弹出所有pushd，你可以使用循环

@echo off
setlocal EnableDelayedExpansion
pushd C:\windows\
pushd c:\windows\system32

:popd_all
echo #: !cd!
popd && goto popd_all