在CMD批处理文件中,我可以确定它是否是从powershell运行的吗?

dvtswwa3  于 2023-08-05  发布在  Shell
关注(0)|答案(4)|浏览(127)

我有一个Windows批处理文件,其目的是设置一些环境变量,例如。

=== MyFile.cmd ===
SET MyEnvVariable=MyValue

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用户可以在执行需要环境变量的工作之前运行此命令,例如:

C:\> MyFile.cmd
C:\> echo "%MyEnvVariable%"    <-- outputs "MyValue"
C:\> ... do work that needs the environment variable


这大致相当于Visual Studio安装的“开发人员命令提示符”快捷方式,它设置了运行VS实用程序所需的环境变量。
但是,如果用户碰巧打开了Powershell提示符,环境变量当然不会传播回Powershell:

PS C:\> MyFile.cmd
PS C:\> Write-Output "${env:MyEnvVariable}"  # Outputs an empty string


这可能会让在CMD和PowerShell之间切换的用户感到困惑。
有没有一种方法可以在我的批处理文件MyFile.cmd中检测到它是从PowerShell调用的,这样我就可以,例如,向用户显示警告?这需要在没有任何第三方实用程序的情况下完成。

flmtquvp

flmtquvp1#

Your own answer is robust,虽然由于需要运行PowerShell进程而通常较慢,但可以通过优化用于确定调用shell的PowerShell命令来显著加快速度:

@echo off
setlocal
CALL :GETPARENT PARENT
IF /I "%PARENT%" == "powershell" GOTO :ISPOWERSHELL
IF /I "%PARENT%" == "pwsh" GOTO :ISPOWERSHELL
endlocal

echo Not running from Powershell 
SET MyEnvVariable=MyValue

GOTO :EOF

:GETPARENT
SET "PSCMD=$ppid=$pid;while($i++ -lt 3 -and ($ppid=(Get-CimInstance Win32_Process -Filter ('ProcessID='+$ppid)).ParentProcessId)) {}; (Get-Process -EA Ignore -ID $ppid).Name"

for /f "tokens=*" %%i in ('powershell -noprofile -command "%PSCMD%"') do SET %1=%%i

GOTO :EOF

:ISPOWERSHELL
echo. >&2
echo ERROR: This batch file must not be run from a PowerShell prompt >&2
echo. >&2
exit /b 1

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在我的机器上,这运行速度大约快3 - 4倍(YMMV)-但仍然需要几乎1秒钟。
请注意,我还添加了对进程名pwsh的检查,以便使解决方案也能与PowerShell Core 一起工作。

更快的替代方案-尽管不太稳健

下面的解决方案依赖于以下假设,默认安装为真
只有一个名为PSModulePathsystem 环境变量被持久地定义在注册表中(也不是一个 * 用户特定的 * 环境变量)。
该解决方案依赖于检测PSModulePath中是否存在用户特定的路径,PowerShell在启动时会自动添加该路径。

@echo off
echo %PSModulePath% | findstr %USERPROFILE% >NUL
IF %ERRORLEVEL% EQU 0 goto :ISPOWERSHELL

echo Not running from Powershell 
SET MyEnvVariable=MyValue

GOTO :EOF

:ISPOWERSHELL
echo. >&2
echo ERROR: This batch file must not be run from a PowerShell prompt >&2
echo. >&2
exit /b 1

按需启动新cmd.exe控制台窗口的替代方法

在前面的方法的基础上,下面的变体只是在检测到批处理文件正在从PowerShell运行时 * 在新的cmd.exe窗口 * 中重新调用批处理文件**。
这不仅对用户更方便,而且还减轻了上述解决方案产生假阳性的问题:当从 * 从PowerShell* 启动的交互式cmd.exe会话运行时,上述解决方案将拒绝运行,即使它们应该运行,正如PetSerAl所指出的那样。
虽然下面的解决方案本身也没有检测到这种情况,但它仍然打开了一个可用的(尽管是新的)窗口,其中设置了环境变量。

@echo off
REM # Unless already being reinvoked via cmd.exe, see if the batch
REM # file is being run from PowerShell.
IF NOT %1.==_isNew. echo %PSModulePath% | findstr %USERPROFILE% >NUL
REM # If so, RE-INVOKE this batch file in a NEW cmd.exe console WINDOW.
IF NOT %1.==_isNew. IF %ERRORLEVEL% EQU 0 start "With Environment" "%~f0" _isNew & goto :EOF

echo Running from cmd.exe, setting environment variables...

REM # Set environment variables.
SET MyEnvVariable=MyValue

REM # If the batch file had to be reinvoked because it was run from PowerShell,
REM # but you want the user to retain the PowerShell experience,
REM # restart PowerShell now, after definining the env. variables.
IF %1.==_isNew. powershell.exe

GOTO :EOF


设置所有环境变量后,请注意最后一个IF语句也是如何重新调用PowerShell的,但在 * 相同 * 的新窗口中,基于调用用户更喜欢在PowerShell中工作的假设。
然后,新的PowerShell会话将看到新定义的环境变量,但请注意,您需要 * 两个 * 连续的exit调用来关闭窗口。

3vpjnl9f

3vpjnl9f2#

就像乔·科克常说的:“我靠朋友的一点帮助过日子。”
在这个例子中,来自Lieven Keersmaekers,他的评论使我得到了以下解决方案:

@echo off
setlocal
CALL :GETPARENT PARENT
IF /I "%PARENT%" == "powershell.exe" GOTO :ISPOWERSHELL
endlocal

echo Not running from Powershell 
SET MyEnvVariable=MyValue

GOTO :EOF

:GETPARENT
SET CMD=$processes = gwmi win32_process; $me = $processes ^| where {$_.ProcessId -eq $pid}; $parent = $processes ^| where {$_.ProcessId -eq $me.ParentProcessId} ; $grandParent = $processes ^| where {$_.ProcessId -eq $parent.ParentProcessId}; $greatGrandParent = $processes ^| where {$_.ProcessId -eq $grandParent.ParentProcessId}; Write-Output $greatGrandParent.Name

for /f "tokens=*" %%i in ('powershell -command "%CMD%"') do SET %1=%%i

GOTO :EOF

:ISPOWERSHELL
echo.
echo ERROR: This batch file may not be run from a PowerShell prompt
echo.
cmd /c "exit 1"
GOTO :EOF

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nmpmafwu

nmpmafwu3#

我为Chocolatey的RefreshEnv.cmd脚本做了这样的事情:Make refreshenv.bat error if powershell.exe is being used
由于不相关的原因,我的解决方案最终没有被使用,但它可以在这个repo中使用:beatcracker/detect-batch-subshell。这是它的副本,以防万一。

仅在从交互式命令处理器会话直接调用时运行的脚本

脚本将检测它是否从非交互式会话(cmd.exe /c detect-batch-subshell.cmd)运行,并显示相应的错误消息。
非交互式shell包括PowerShell/PowerShell伊势、Explorer等。基本上,任何试图通过在单独的cmd.exe示例中运行脚本来执行脚本的东西。
然而,从PowerShell/PowerShell伊势进入cmd.exe会话并在那里执行脚本将起作用。

依赖关系

  • wmic.exe-随Windows XP Professional及更高版本提供。

示例:

1.打开cmd.exe
1.型号detect-batch-subshell.cmd

输出:

> detect-batch-subshell.cmd

Running interactively in cmd.exe session.

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示例:

1.打开powershell.exe
1.型号detect-batch-subshell.cmd

输出:

PS > detect-batch-subshell.cmd

detect-batch-subshell.cmd only works if run directly from cmd.exe!

代码

  • detect-batch-subshell.cmd
@echo off

setlocal EnableDelayedExpansion

:: Dequote path to command processor and this script path
set ScriptPath=%~0
set CmdPath=%COMSPEC:"=%

:: Get command processor filename and filename with extension
for %%c in (!CmdPath!) do (
    set CmdExeName=%%~nxc
    set CmdName=%%~nc
)

:: Get this process' PID
:: Adapted from: http://www.dostips.com/forum/viewtopic.php?p=22675#p22675
set "uid="
for /l %%i in (1 1 128) do (
    set /a "bit=!random!&1"
    set "uid=!uid!!bit!"
)

for /f "tokens=2 delims==" %%i in (
    'wmic Process WHERE "Name='!CmdExeName!' AND CommandLine LIKE '%%!uid!%%'" GET ParentProcessID /value'
) do (
    rem Get commandline of parent
    for /f "tokens=1,2,*" %%j in (
        'wmic Process WHERE "Handle='%%i'" GET CommandLine /value'
    ) do (

        rem Strip extra CR's from wmic output
        rem http://www.dostips.com/forum/viewtopic.php?t=4266
        for /f "delims=" %%x in ("%%l") do (
            rem Dequote path to batch file, if any (3rd argument)
            set ParentScriptPath=%%x
            set ParentScriptPath=!ParentScriptPath:"=!
        )

        rem Get parent process path
        for /f "tokens=2 delims==" %%y in ("%%j") do (
            rem Dequote parent path
            set ParentPath=%%y
            set ParentPath=!ParentPath:"=!

            rem Handle different invocations: C:\Windows\system32\cmd.exe , cmd.exe , cmd
            for %%p in (!CmdPath! !CmdExeName! !CmdName!) do (
                if !ParentPath!==%%p set IsCmdParent=1
            )

            rem Check if we're running in cmd.exe with /c switch and this script path as argument
            if !IsCmdParent!==1 if %%k==/c if "!ParentScriptPath!"=="%ScriptPath%" set IsExternal=1
        )
    )
)

if !IsExternal!==1 (
    echo %~nx0 only works if run directly from !CmdExeName!^^!
    exit 1
) else (
     echo Running interactively in !CmdExeName! session.
 )

endlocal

ejk8hzay

ejk8hzay4#

就像beatcracker的答案一样,我认为最好不要对可用于启动批处理脚本的外部shell进行假设,例如,通过bash shell运行批处理文件时也会出现问题。
因为它只使用CMD的本机工具,不依赖于任何外部工具或WMI,所以执行时间非常快。

@echo off
call :IsInvokedInternally && (
    echo Script is launched from an interactive CMD shell or from another batch script.
) || (
    echo Script is invoked by an external App. [PowerShell, BASH, Explorer, CMD /C, ...]
)
exit /b

:IsInvokedInternally
setlocal EnableDelayedExpansion
:: Getting substrings from the special variable CMDCMDLINE,
:: will modify the actual Command Line value of the CMD Process!
:: So it should be saved in to another variable before applying substring operations.
:: Removing consecutive double quotes eg. %systemRoot%\system32\cmd.exe /c ""script.bat""
set "SavedCmdLine=!cmdcmdline!"
set "SavedCmdLine=!SavedCmdLine:""="!"
set /a "DoLoop=1, IsExternal=0"
set "IsCommand="
for %%A in (!SavedCmdLine!) do if defined DoLoop (
    if not defined IsCommand (
        REM Searching for /C switch, everything after that, is CMD commands
        if /i "%%A"=="/C" (
            set "IsCommand=1"
        ) else if /i "%%A"=="/K" (
            REM Invoking the script with /K switch creates an interactive CMD session
            REM So it will be considered an internal invocatoin
            set "DoLoop="
        )
    ) else (
        REM Only check the first command token to see if it references this script
        set "DoLoop="

        REM Turning delayed expansion off to prevent corruption of file paths
        REM which may contain the Exclamation Point (!)
        REM It is safe to do a SETLOCAL here because the we have disabled the Loop,
        REM and the routine will be terminated afterwards.
        setlocal DisableDelayedExpansion
        if /i "%%~fA"=="%~f0" (
            set "IsExternal=1"
        ) else if /i "%%~fA"=="%~dpn0" (
            set "IsExternal=1"
        )
    )
)
:: A non-zero ErrorLevel means the script is not launched from within CMD.
exit /b %IsExternal%

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它检查用于启动CMD shell的命令行,以判断脚本是从CMD内部启动的,还是由外部应用程序使用命令行签名/C script.bat启动的,/C script.bat通常由非CMD shell用于启动批处理脚本。
如果出于任何原因需要绕过外部启动检测,例如当使用其他命令手动启动脚本以利用定义的变量时,可以通过在CMD命令行中将@前置到脚本的路径来完成:

cmd /c @MyScript.bat & AdditionalCommands

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