How do I pass named parameters with Invoke-Command?

My solution to this was to write the script block dynamically with [scriptblock]:Create:

# Or build a complex local script with MARKERS here, and do substitutions
# I was sending install scripts to the remote along with MSI packages
# ...for things like Backup and AV protection etc.

$p1 = "good stuff"; $p2 = "better stuff"; $p3 = "best stuff"; $etc = "!"
$script = [scriptblock]::Create("MyScriptOnRemoteServer.ps1 $p1 $p2 $etc")
#strings get interpolated/expanded while a direct scriptblock does not

# the $parms are now expanded in the script block itself
# ...so just call it:
$result = invoke-command $computer -script $script

Passing arguments was very frustrating, trying various methods, e.g.,
-arguments, $using:p1, etc. and this just worked as desired with no problems.

Since I control the contents and variable expansion of the string which creates the [scriptblock] (or script file) this way, there is no real issue with the "invoke-command" incantation.

(It shouldn't be that hard. :) )

-ArgumentList is based on use with scriptblock commands, like:

Invoke-Command -Cn (gc Servers.txt) {param($Debug=$False, $Clear=$False) C:\Scripts\ArchiveEventLogs\ver5\ArchiveEventLogs.ps1 } -ArgumentList $False,$True

When you call it with a -File it still passes the parameters like a dumb splatted array. I've submitted a feature request to have that added to the command (please vote that up).

So, you have two options:

If you have a script that looked like this, in a network location accessible from the remote machine (note that -Debug is implied because when I use the Parameter attribute, the script gets CmdletBinding implicitly, and thus, all of the common parameters):

param(
   [Parameter(Position=0)]
   $one
,
   [Parameter(Position=1)]
   $two
,
   [Parameter()]
   [Switch]$Clear
)

"The test is for '$one' and '$two' ... and we $(if($DebugPreference -ne 'SilentlyContinue'){"will"}else{"won't"}) run in debug mode, and we $(if($Clear){"will"}else{"won't"}) clear the logs after."

Without getting hung up on the meaning of $Clear ... if you wanted to invoke that you could use either of the following Invoke-Command syntaxes:

icm -cn (gc Servers.txt) { 
    param($one,$two,$Debug=$False,$Clear=$False)
    C:\Scripts\ArchiveEventLogs\ver5\ArchiveEventLogs.ps1 @PSBoundParameters
} -ArgumentList "uno", "dos", $false, $true

In that one, I'm duplicating ALL the parameters I care about in the scriptblock so I can pass values. If I can hard-code them (which is what I actually did), there's no need to do that and use PSBoundParameters, I can just pass the ones I need to. In the second example below I'm going to pass the $Clear one, just to demonstrate how to pass switch parameters:

icm -cn $Env:ComputerName { 
    param([bool]$Clear)
    C:\Scripts\ArchiveEventLogs\ver5\ArchiveEventLogs.ps1 "uno" "dos" -Debug -Clear:$Clear
} -ArgumentList $(Test-Path $Profile)

The other option

If the script is on your local machine, and you don't want to change the parameters to be positional, or you want to specify parameters that are common parameters (so you can't control them) you will want to get the content of that script and embed it in your scriptblock:

$script = [scriptblock]::create( @"
param(`$one,`$two,`$Debug=`$False,`$Clear=`$False)
&{ $(Get-Content C:\Scripts\ArchiveEventLogs\ver5\ArchiveEventLogs.ps1 -delimiter ([char]0)) } @PSBoundParameters
"@ )

Invoke-Command -Script $script -Args "uno", "dos", $false, $true

PostScript:

If you really need to pass in a variable for the script name, what you'd do will depend on whether the variable is defined locally or remotely. In general, if you have a variable $Script or an environment variable $Env:Script with the name of a script, you can execute it with the call operator (&): &$Script or &$Env:Script

If it's an environment variable that's already defined on the remote computer, that's all there is to it. If it's a local variable, then you'll have to pass it to the remote script block:

Invoke-Command -cn $Env:ComputerName { 
    param([String]$Script, [bool]$Clear)
    & $ScriptPath "uno" "dos" -Debug -Clear:$Clear
} -ArgumentList $ScriptPath, (Test-Path $Profile)