Pass a Hashtable as Parameter to powershell.exe

Question

How do I pass a hashtable as parameter to powershell.exe?

The powershell.exe is started by the IntuneManagementExtension. The behavior can be reproduce by start a powershell.exe from a running powershell console.

OutHash.ps1:

Param(
   [hashtable]$hash
)

$hash

Call:

powershell.exe -File .\OutHash.ps1 -hash @{'A'=1}

Output:

Cannot process argument transformation on parameter 'hash'. Cannot convert the "System.Collections.Hashtable" value of type "System.String" to type "System.Collections.Hashtable".

Expected output:

Name                           Value                                                                                                                                                                                                                             
----                           -----                                                                                                                                                                                                                             
A                              1

Inside the powershell console, this call returns the expected output:

.\OutHash.ps1 -hash @{'A'=1}

You don't. The operating system's execution environment has no concept of a "hashtable", all you can pass is strings. — Mathias R. Jessen, Aug 30 '22 at 10:56
You will need to stringify (serialize) it, see: [Is there a way to pass serializable objects to a PowerShell script with start-process?](https://stackoverflow.com/q/34076478/1701026) — iRon, Aug 30 '22 at 11:00
From where do you launch the `PowerShell.exe` command? (please [add that to the question](https://stackoverflow.com/posts/73541224/edit)) — iRon, Aug 30 '22 at 13:50
@iRon depending on your serialize input, it works fine for me using a string parameter and converting to a hashtable — fabian, Aug 31 '22 at 14:37
@MathiasR.Jessen This comment untied a knot in my brain, thank you so much. I've been trying to pass a hash table to `pwsh -c { my_command_that_uses_hashtable_here }`, but now I understand why nothing I'm trying to do works. I guess I have to pass each individual value as a named parameter instead. Thank you for clarifying. — Adrian Wiik, Nov 10 '22 at 11:26

score 1 · Answer 1 · answered Aug 30 '22 at 11:23

1

My "userfriendly" serialized solution:

Param(

    [string]$String
)

$Hash = $String -replace ",","`n" | ConvertFrom-StringData
$Hash

Call

powershell -file .\OutHash.ps1 -String "A=1,B=1"

answered Aug 30 '22 at 11:23

fabian

63
5

iRon · Answer 2 · 2022-08-30T13:53:40.687

As commented by @Mathias:

You don't. The operating system's execution environment has no concept of a "hashtable", all you can pass is strings.

From the error message, I presume that you launching the PowerShell.exe command from PowerShell itself, as a alternative supporting complex hash tables, you might encode your command including the hashtable and invoke that:

$Command        = { .\OutHash.ps1 -hash @{ 'e-mail' = 'doe,john@fabrikam.com' } }
$Bytes          = [System.Text.Encoding]::Unicode.GetBytes($Command.ToString())
$EncodedCommand = [Convert]::ToBase64String($Bytes)

PowerShell.exe -EncodedCommand $EncodedCommand

js2010 · Answer 3 · 2022-08-31T14:58:35.770

0

The default -Command works from cmd. It should work from Intune. You may have to put the full path to the script. "-command" and "-hash" are optional.

powershell.exe -command c:\temp\outhash.ps1 -hash @{A=1}

Name                           Value
----                           -----
A                              1

edited Aug 31 '22 at 14:58

answered Aug 30 '22 at 13:20

js2010

23,033
6
64
66

that is probably from the cmd prompt. I think the OP needs to add (to the question) from where he is launching the command... – iRon Aug 30 '22 at 13:48

Pass a Hashtable as Parameter to powershell.exe

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