When deploying PowerShell scripts from my RMM (NinjaOne), the scripts are called from a .bat (batch file).

Example:

@powershell -ExecutionPolicy Bypass -File "test.ps1" -stringParam "testing" -switchParam > "output.txt" 2>&1

The script I am calling requires PowerShell 7 , so I need to restart the script by calling pwsh with the current parameters. I planned to accomplish this via the following:

Invoke-Command { & pwsh -Command $MyInvocation.Line } -NoNewScope

Unfortunately, $MyInvocation.Line does not return the correct result when a PowerShell script is called from a batch file. What alternatives exist that would work in this scenario?

Notes:

• I am unable to make changes to the .bat file.
• $PSBoundParameters also does not return the expected result.

Edit: I've discovered the reason for $MyInvocation / $PSBoundParameters not being set properly is due to the use of -File instead of -Command when my RMM provider calls the PowerShell script from the .bat file. I've suggested they implement this change to resolve the issue. Until they do, I am still looking for alternatives.

CodePudding user response：

I'd try putting a file called powershell.bat early on your path (at least, in a directory earlier on the path than the C:\Windows\System32\WindowsPowerShell\v1.0\; entry) and assemble the appropriate parameters (I've no idea of your required structure for $myinvocationline - no doubt it could be derived from the parameters delivered to powershell.bat).

My thinking is that this should override powershell, re-assemble the bits and deliver them to pwsh.

CodePudding user response：

I put this line in test.ps1:

$MyInvocation | Format-List -Property *

Found this content in output.txt:

MyCommand             : test.ps1
BoundParameters       : {}
UnboundArguments      : {-stringParam, testing, -switchParam}
ScriptLineNumber      : 0
OffsetInLine          : 0
HistoryId             : 1
ScriptName            : 
Line                  : 
PositionMessage       : 
PSScriptRoot          : 
PSCommandPath         : 
InvocationName        : D:\Temp\StackOverflow\71087897\test.ps1
PipelineLength        : 2
PipelinePosition      : 1
ExpectingInput        : False
CommandOrigin         : Runspace
DisplayScriptPosition : 

Then tried this in test.ps1:

[string]$MySelf = $MyInvocation.InvocationName
Write-Host "###$MySelf###"
[string[]]$Params = $MyInvocation.UnboundArguments
foreach ($Param in $Params) {
    Write-Host "Param: '$Param'"
}

And found this in output.txt:

###D:\Temp\StackOverflow\71087897\test.ps1###
Param: '-stringParam'
Param: 'testing'
Param: '-switchParam'

Then tried this in test.ps1:

[string]$Line = "$($MyInvocation.InvocationName) $($MyInvocation.UnboundArguments)"
Write-Host "$Line"

And found this in output.txt:

D:\Temp\StackOverflow\71087897\test.ps1 -stringParam testing -switchParam

Does this get you to where you need to be?

CodePudding user response：

Leaving RMM providers out of the picture (whose involvement may or may not matter), the following test.ps1 content should work:

# Note: Place [CmdletBinding()] above param(...) to make
#       the script an *advanced* one, which then prevents passing
#       arguments that don't bind to declared parameters.
param(
  [string] $stringParam,
  [switch] $switchParam
)

# If invoked via powershell.exe, re-invoke via pwsh.exe
if ((Get-Process -Id $PID).Name -eq 'powershell') {
   # $PSCommandPath is the current script's full file path,
   # and @PSBoundParameters uses splatting to pass all bound arguments through.
   pwsh -ExecutionPolicy Bypass -File $PSCommandPath @PSBoundParameters
   exit $LASTEXITCODE
}

# Getting here means that the file is being executed by pwsh.exe

# Print the bound parameters.
$PSBoundParameters

exit 0

The above assumes that only arguments for formally declared parameters are passed; if you do want to support extra arguments, append @args to the pwsh -ExecutionPolicy Bypass -File $PSCommandPath @PSBoundParameters line above.
Alternatively, as suggested in the code comments, place [CmdletBinding()] above the param(...) block, which makes the script an advanced one, in which case passing extra arguments is actively prevented (and in which case $args isn't defined).

---

As for what you tried:

• $MyInvocation.Line isn't defined when a script is called via PowerShell's CLI; however, the automatic $PSCommandPath variable, reflecting the running script's full file path, is defined.

  • Even if $MyInvocation.Line were defined, it wouldn't enable robust pass-through of the original arguments, due to potential quoting issues and - when called from inside PowerShell - due to reflecting unexpanded arguments.

• Also, it is virtually pointless to use Invoke-Command for local invocations - see this answer.