将param块后的语句注入PowerShell Here-String

Question

我有一个here字符串，我想在参数块之后注入一个语句。挑战是，我不知道Here-String的结构，它应该适用于各种Here-Strings（有和没有param块）。

例如：

$scriptBlock = @'

Param (
    [Parameter(Mandatory=$false)][string]$param1,
    [Parameter(Mandatory=$false)][string]$param2,
    [Parameter(Mandatory=$false)][switch]$param3
)

Write-Output ('param1: {0}' -f $param1)
Write-Output ('param2: {0}' -f $param2)
Write-Output ('param3: {0}' -f $param3)

Get-Location
'@

invoke-expression "$scriptBlock"

在param块之后我想注入以下语句。

Set-Location C:\temp

结果应如下所示：

$scriptBlock = @'

Param (
    [Parameter(Mandatory=$false)][string]$param1,
    [Parameter(Mandatory=$false)][string]$param2,
    [Parameter(Mandatory=$false)][switch]$param3
)
Set-Location C:\temp

Write-Output ('param1: {0}' -f $param1)
Write-Output ('param2: {0}' -f $param2)
Write-Output ('param3: {0}' -f $param3)

Get-Location
'@

invoke-expression "$scriptBlock"

Answer 1

怎么样？

代码

$scriptcontent = [System.Management.Automation.Language.Parser]::ParseInput($scriptblock, [ref]$null, [ref]$null)
$paramblock = $scriptcontent.ParamBlock
if ($paramblock) {
    $scriptblock = $scriptblock.Replace($paramblock.Extent.Text, $paramblock.Extent.Text + "`nSet-Location C:\temp;`n")
}
$scriptblock

结果

Param (
    [Parameter(Mandatory=$false)][string]$param1,
    [Parameter(Mandatory=$false)][string]$param2,
    [Parameter(Mandatory=$false)][switch]$param3
)

Set-Location C:\temp;


Write-Output ('param1: {0}' -f $param1)
Write-Output ('param2: {0}' -f $param2)
Write-Output ('param3: {0}' -f $param3)

Get-Location