Wrapper function in PowerShell: Pass remaining parameters

问题

I’m trying to write a wrapper function in PowerShell that basically evaluates the first parameter and based on that runs a program on the computer. All the remaining parameters to the wrapper function should then be passed to the program that is ran as well.

So it should look something like this:

function test ( [string] $option )
{
    if ( $option -eq 'A' )
    {
        Write-Host $args
    }
    elseif ( $option -eq 'B' )
    {
        . 'C:\Program Files\some\program.exe' $args
    }
}

Now just adding $args does not work, so what do I have to do to make it work? Another option would probably be using Invoke-Expression, but it feels a bit like eval so I want to avoid if possible, and in addition I think doing it like that would limit me to string-only parameters right? If possible I would want to have the full support for the wrapped program/cmdlet - basically like a dynamic alias. Is that even possible?

回答1:

This sort of does what you ask. You may run into trouble if you need to pass dash-prefixed options to the executable that conflict or cause ambiguity with the PowerShell common parameters. But this may get you started.

function Invoke-MyProgram
{
    [CmdletBinding()]
    Param
    (
        [parameter(mandatory=$true, position=0)][string]$Option,
        [parameter(mandatory=$false, position=1, ValueFromRemainingArguments=$true)]$Remaining
    )

    if ($Option -eq 'A')
    {
        Write-Host $Remaining
    }
    elseif ($Option -eq 'B')
    {
        & 'C:\Program Files\some\program.exe' @Remaining # NOTE: @ not $ (splatting)
    }
}

回答2:

What you have written ( except for the syntax error at else if - it should be elseif ) does work. Note that what is there is $args is the unnamed arguments that are over and above the parameters expected by the function.

So if you call test as

test -option "A" 1 2 3

$args will have 1,2,3

Note that if you call test as

test -option "A" -other "B" 1 2 3

$args will have -other,B,1,2,3

来源：https://stackoverflow.com/questions/7415883/wrapper-function-in-powershell-pass-remaining-parameters

标签

powershell

parameters