从PowerShell cmdlet返回错误的最佳做法是什么？

我正在为我们的应用程序配置需求编写一个基于PowerShell的XML模块。以下是其中一个函数

<#
.Synopsis
   To update an XML attribute value
.DESCRIPTION
   In the XML file for a particular attribute, if it contains valueToFind then replace it with valueToReplace
.EXAMPLE

-------------------------------Example 1 -------------------------------------------------------------------
   Update-XMLAttribute -Path "C:\web.Config" -xPath "/configuration/system.serviceModel/behaviors/serviceBehaviors/behavior/serviceMetadata" -attribute "externalMetadataLocation" -valueToFind "http:" -ValueToReplace "https:"

   Look for the XPath expression with the attribute mentioned and search whether the value contains "http:". If so, change that to "https":
.EXAMPLE

-------------------------------Example 2 -------------------------------------------------------------------
   Update-XMLAttribute -Path "C:\web.Config" -xPath "/configuration/system.serviceModel/behaviors/serviceBehaviors/behavior/serviceMetadata" -attribute "externalMetadataLocation" -valueToFind "http:" -ValueToReplace "https:"

   Same as Example 1 except that the attribute name is passed as part of the XPath expression

#>
function Update-XMLAttribute
{
    [CmdletBinding()]
    [OutputType([int])]
    Param
    (
        # Web configuration file full path
        [Parameter(Mandatory=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        [string]$Path,

        # XPath expression up to the parent node
        [string] $xPath,
        # This parameter is optional if you mentioned it in xPath itself
        [string] $attribute,

        [string] $valueToFind,

        [string] $ValueToReplace
    )

    Try
    {
        If (Test-path -Path $Path)
        {
                    $xml = New-Object XML
                    $xml.Load($Path)

                    # If the xPath expression itself contains an attribute name then the value of attribute will be processed and taken
                    If ($xPath.Contains("@")) {
                        $xPath, $attribute = $xPath -split '/@', 2
                    }

                    # Getting the node value using xPath
                    $Items  = Select-Xml -XML $xml -XPath $xPath
                    ForEach ($Item in $Items)
                    {

                        $attributeValue = $Item.node.$attribute
                        Write-Verbose "Attribute value is $attributeValue "

                        if ($attributeValue.contains($valueToFind)) {


                            Write-Verbose "In the attribute $attributeValue - $valueToFind is to be repalced with $ValueToReplace"
                            $Item.node.$attribute = $attributeValue.replace($valueToFind, $ValueToReplace)
                        }
                    }

                    $xml.Save($Path)
                    Write-Verbose " Update-XMLAttribute is completed successfully"
        }
        Else {
            Write-Error " The $path is not present"
        }

    }
    Catch {
        Write-Error "$_.Exception.Message"
        Write-Error "$_.Exception.ItemName"
        Write-Verbose " Update-XMLAttribute is failed"
    }
} # End Function Update-XMLAttribute

由于这个cmdlet将被许多人使用，我不认为简单地写入控制台是正确的方法

现在在我的脚本中如果没有错误，我可以假设我的脚本已经成功完成

从PowerShell cmdlet获取结果以使使用者知道其是否已成功完成的标准做法是什么？

如果函数遇到错误，则应选择该函数。由调用方决定如何处理错误忽略、记录消息、终止等等。

标准做法是抛出异常。每个不同类型的错误都有一个单独的异常类型，可用于进一步诊断

假设文件未表示，则执行以下操作：

if (-not (Test-Path $file))
{
    throw [System.IO.FileNotFoundException] "$file not found."
}

---

您的cmdlet应该记录它将引发的所有可能的异常，以及何时引发。

虽然您可以引发异常，PowerShell将捕获该异常并将其包装到ErrorRecord中，但您可以更灵活地使用该方法。这是基于C的cmdlet的典型方法

ThrowTerminatingError(new ErrorRecord(_exception, _exception.GetType().Name, ErrorCategory.NotSpecified, null));

这允许您选择错误类别并提供目标对象。顺便说一句，上面提到的不是我所说的cmdlet。cmdlet通常是用C语言编译的。您拥有的是一个高级功能：-

您可以通过高级功能访问此方法，如下所示：

$pscmdlet.ThrowTerminatingError(...)