如何将 If 语句传递给 PowerShell 的启动进程的参数列表？

Question

if ($PSVersionTable.PSVersion.Major,$PSVersionTable.PSVersion.Minor -join "." -gt 5.1) {   
    
Start-Process -FilePath "PowerShell.exe" -ArgumentList 'if((get-WindowsOptionalFeature -Online -FeatureName SmbDirect).state -eq "disabled"){Enable-WindowsOptionalFeature -Online -FeatureName SmbDirect -norestart}'
}

else
{
if((get-WindowsOptionalFeature -Online -FeatureName SmbDirect).state -eq "disabled"){Enable-WindowsOptionalFeature -Online -FeatureName SmbDirect -norestart}
}

even though I made it a one-liner, It still won't work. the result is a new PowerShell window opening for a split second and closing.

how can I make it work?

I studied the Argumentlist but couldn't find a way.

Answer 1

This looks like a "losing the doublequotes problem".

powershell '"a"'

a : The term 'a' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and
try again.

Swap the single and doublequotes. Not that start-process is needed. See also PowerShell stripping double quotes from command line arguments

Start-Process -FilePath "PowerShell.exe" -ArgumentList "if((get-WindowsOptionalFeature -Online -FeatureName SmbDirect).state -eq 'disabled'){Enable-WindowsOptionalFeature -Online -FeatureName SmbDirect -norestart}"

Answer 2

tl;dr

• To make your command work, escaped the embedded " chars in your -ArgumentList argument as \" .

  • Alternatively, use embedded ' chars escaped as '' , or use "..." for the outer quoting, in which case you can use ' as-is - but note that this bears the risk of up-front expansion of variable references and expressions, unless you escape $ instances as `$ .

• However, Start-Process may not be the best way to invoke your command ; if synchronous invocation with output to the caller's console is desired / acceptable, use a script block to pass your command as-is (works from inside PowerShell only):

   PowerShell.exe { if((get-WindowsOptionalFeature -Online -FeatureName SmbDirect).state -eq "disabled"){Enable-WindowsOptionalFeature -Online -FeatureName SmbDirect -norestart} }

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Background information:

js2010's answer provides effective solutions, but let me try to provide a systematic overview of the issues involved , to avoid potential misconceptions:

• Calling powershell.exe , the Windows PowerShell CLI (or its PowerShell (Core) equivalent, pwsh , from PowerShell is rarely necessary .

  • You state that in your case you did need to do so, from PowerShell (Core) 7+ , because functionality wasn't available in the latter, due to a potential bug .

• As with any external program , you have two basic invocation choices :

  • Direct invocation (possibly via & , the call operator , which is situationally required for syntactic reasons ).

    • Direct invocation is usually the right approach, as it executes the program synchronously , with the program's output streams connected to PowerShell's, which by default displays them in the caller's console .

    • From inside PowerShell , irrespective of whether you're calling the respective other edition on Windows, using a script block ( {... } ) is the best choice - see this answer .

  • Invocation via Start-Process , which by default executes asynchronously , in a new window , and is therefore only needed in special circumstances .

    • See GitHub docs issue #6239 for guidance on when use of Start-Process is and isn't appropriate.

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The fundamental problem with your own approach is that any " characters in the -ArgumentList argument must be escaped as \" :

• Passing a piece of PowerShell code to a PowerShell CLI's -Command ( -c ) parameter ( by default with powershell.exe only, explicitly with pwsh ) employs two parsing passes :

  • In short: unescaped " chars. are stripped during command-line parsing , and only then are the argument(s) interpreted as PowerShell code .

    • See this answer for details.

  • Any " characters you want to be part of the PowerShell code to evaluate , must be escaped .

    • Using embedded '...' quoting, if possible, is a way to avoid this need.
    • PowerShell itself, in both editions, always recognizes \" as an escaped " , but when calling from cmd.exe , different forms are needed in edge cases - see this answer .

• When using Start-Process with a single-string -ArgumentList argument:

  • The (possibly preprocessed by PowerShell) string's verbatim value becomes part of the raw process command line that is constructed behind the scenes, so using \" to escape " chars. is enough.

• When using direct invocation :

  • It is reasonable to expect PowerShell to automatically escape embedded " characters, such as when calling powershell.exe '"hi"'

    • However, due to a long-standing bug up to v7.2.x, this does not work as expected - see this answer .

  • In PowerShell 7.3.0 and 7.3.1 , specifically, it does work as expected by default , however, a future update will likely require opt-in - see GitHub issue #18694