calling Invoke-Expression with Parameters in Powershell

Question:

I’ve written a powershell module in c# that has a bunch of cmdlets like

Add-VM

The cmdlets reach out to an API and pull data back.

but for the sake of uniformity with the ssh CLI of the product, i’ve written a function called newtask that accepts ‘addvm’ as an argument and $args.

for example

I then invoke Add-VM and pass $args as a string like so

The problem is that Add-VM throws an error that it cannot find a positional parameter that accepts argument System.Object[]

A positional parameter cannot be found that accepts argument ‘System.Object[]’

While I could easily alias ‘addvm’ to ‘Add-VM’, i’m trying to maintain uniformity with the ssh CLI so that new users can quickly start utilizing this module.

I figured that sending a string like ‘-id 12345’ would suffice but it’s not. Does the pscmdlet expect to receive something else?

Thanks in advance.

Answer:

That error is from Invoke-Expression not Add-VM and you just need quotes around the argument:


This has the drawback of forcing all objects into string format. This might be acceptable for simple types like ints and strings but if you want to pass through a more complex object it won’t work. An alternative would be to splat the arguments with @args but I don’t think you can do this through Invoke-Expression or Invoke-Command. You need to directly call the cmdlet:

Source:

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