PowerShell Pass Named parameters to ArgumentList

Question

I have a PowerShell script that accepts 3 named parameters. Please let me know how to pass the same from command line. I tried below code but same is not working. It assigns the entire value to P3 only. My requirement is that P1 should contain 1, P2 should 2 and P3 should be assigned 3.

Invoke-Command -ComputerName server -FilePath "D:\test.ps1" -ArgumentList  {-P1 1 -P2 2 -P3 3}

Ihe below is script file code.

Param (
    [string]$P3,
    [string]$P2,
    [string]$P1
)
Write-Output "P1 Value :" $P1
Write-Output "P2 Value:" $P2
Write-Output "P3 Value :" $P3

Solution 1

One option:

$params = @{
P1 = 1
P2 = 2 
P3 = 3
}

$ScriptPath = 'D:\Test.ps1'

$sb = [scriptblock]::create(".{$(get-content $ScriptPath -Raw)} $(&{$args} @params)")

Invoke-Command -ComputerName server -ScriptBlock $sb

Solution 2

The code by mjolinor works great, but it took me several minutes to understand it.

The code makes a simple thing - generates a content of script block with built-in parameters:

&{
    Param (
        [string]$P3,
        [string]$P2,
        [string]$P1
    )
    Write-Output "P1 Value:" $P1
    Write-Output "P2 Value:" $P2
    Write-Output "P3 Value:" $P3
} -P1 1 -P2 2 -P3 3

Then this script block is passed to Invoke-Command.

To simplify the code:

".{$(get-content $ScriptPath -Raw)} $(&{$args} @params)"

$scriptContent = Get-Content $ScriptPath -Raw
$formattedParams = &{ $args } @params
# The `.{}` statement could be replaced with `&{}` here, because we don't need to persist variables after script call.
$scriptBlockContent = ".{ $scriptContent } $formattedParams"
$sb = [scriptblock]::create($scriptBlockContent)

Let's make a basic C# implementation:

void Run()
{
    var parameters = new Dictionary<string, string>
    {
        ["P1"] = "1",
        ["P2"] = "2",
        ["P3"] = "3"
    };

    var scriptResult = InvokeScript("Test.ps1", "server", parameters)
    Console.WriteLine(scriptResult);
}

string InvokeScript(string filePath, string computerName, Dictionary<string, string> parameters)
{
    var innerScriptContent = File.ReadAllText(filePath);
    var formattedParams = string.Join(" ", parameters.Select(p => $"-{p.Key} {p.Value}"));
    var scriptContent = "$sb = { &{ " + innerScriptContent + " } " + formattedParams + " }\n" +
        $"Invoke-Command -ComputerName {computerName} -ScriptBlock $sb";

    var tempFile = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + ".ps1");
    File.WriteAllText(tempFile, scriptContent);

    var psi = new ProcessStartInfo
        {
            FileName = "powershell",
            Arguments = $@"-ExecutionPolicy Bypass -File ""{tempFile}""",
            RedirectStandardOutput = true,
            UseShellExecute = false
        };

    var process = Process.Start(psi);
    var responseText = process.StandardOutput.ReadToEnd();

    File.Delete(tempFile);

    return responseText;
}

The code generates a temporary script and executes it.

Example script:

$sb = {
    &{
        Param (
            [string]$P3,
            [string]$P2,
            [string]$P1
        )
        Write-Output "P1 Value:" $P1
        Write-Output "P2 Value:" $P2
        Write-Output "P3 Value:" $P3
     } -P1 1 -P2 2 -P3 3
}
Invoke-Command -ComputerName server -ScriptBlock $sb

Solution 3

Here's a simple solution:

[PowerShell]::Create().AddCommand('D:\test.ps1').AddParameters(@{ P1 = 1; P2 = 2; P3 = 3 }).Invoke()

Here's output:

PS C:\Windows\system32> [PowerShell]::Create().AddCommand('D:\test.ps1').AddParameters(@{ P1 = 1; P2 = 2; P3 = 3 }).Invoke()
P1 Value :
1
P2 Value:
2
P3 Value :
3

Solution 4

If you are trying to use the -FilePath with named parameters (-P1 1 -P2 2), then I found this will work. Use a script block to run the file, instead of the using -FilePath.

Invoke-Command -ComputerName server -ScriptBlock {& "D:\test.ps1" -P1 1 -P2 2 -P3 3}

View more solutions

Comments

[Parveen Kumar]

can you please provide more details on this.

[Parveen Kumar]

Yes I am able to achieve the result using the above code.

[Parveen Kumar]

Can you please let me know how to achieve the same using C# code as my requirement is to run this PowerShell script from C#.

[mjolinor]

Sorry, don't know C# well enough to convert that for you.

[CarlR]

This code works really well until you have an array as a parameter. When that happens you just get "System.String[]" as the value since the param block effectively gets a .ToString() applied to it when it gets expanded. I have yet to find a reliable way of avoiding this, if anyone has a solution i would love to see it!

[mjolinor]

@CarlR - Try P3 = "@('a','b','c')"

[sephirot]

It works well. To pass string with spaces you have to wrap value with additional apostrophe. E.g. P1 = "'My string parameter'"

[Eric Eskildsen]

This doesn't work—the entire hashtable is passed as the first argument. The docs say the arguments need to be a comma-separated list (non-associative array) (source).

[batbrat]

Could you please explain what $(&{args}) does? I'm trying to understand how that combines with @params to give you a string like "-P1 1 -P2 2 -P3 3".

[mjolinor]

Working from the inside out, {$args} is a script block that simply returns whatever arguments it's been given. &{args} executes the script block. Wrapping it in $() - $(&{$args}) makes it a subexpression, so that it expands within the string. Because the argument given was a hash table, the output is a series of key/value pairs - the result of the splatting operation as it was passed to the script block.

[Garric]

Only this code returned me the result from another external function

[Garric]

Invoke-Command was unable to return the win form to me as a result of execution

[Garric]

My form was on over thread, but your code worked fine.

[Garric]

Yes, more. Your solution doesn't break whitespace, unlike $sb = [scriptblock]::create(".{$(get-content $ScriptPath -Raw)} $(&{$args} @params)")

[tommylux]

I love this solution and your explanation is great. However, What if your variable is a string with spaces in, how can I encapsulate the args like so: "-P2 'This is P2' -P1 'This Is P1' -P3 'This is P3'"

[tommylux]

Can you better this? IF ($StrArgs -is [Hashtable]) { $formattedParams = Foreach ($i in $StrArgs.keys) { "-${i}: "$($StrArgs.$i)"" } } Else { $formattedParams = $StrArgs }