Question

I’m having trouble running powershell with a script that should use a variable number of parameters.

The script file looks like this:

param( [string]$paramString )

$params = ConvertFrom-StringData $paramString
$params

Running the script directly in powershell yields the expected result:

[PS] C:\some\path>.\test.ps1 "a=foo `n b=bar `n c=moo"

Name                           Value
----                           -----
c                              moo
a                              foo
b                              bar

Calling powershell from the command line with the same script and parameters shows this:

C:\some\path>powershell -nologo -file ./test.ps1 "a=foo `n b=bar `n c=moo"

Name                           Value
----                           -----
a                              foo `n b=bar `n c=moo

It seems like the passed string is in some format so the ConvertFrom-StringData function is unable to parse it anymore.

Answer 1

Approach with -File is problematic because the parameter is not evaluated by cmd (at it is in PowerShell) and new lines equivalents are not expanded, they are passed in literally.

The problem can be solved if we still let PowerShell to do that by using -Command instead:

powershell -nologo -command "./test.ps1 ""a=foo `n b=bar `n c=moo"""

It is ugly: we have to double every inner " in the command. But it works. (The command can be defined by several parameters; I just prefer to use a single parameter: this way looks simpler to me).