在添加到 $Error 变量时抑制 Powershell 错误

Question

我有一个代码块正在执行，它设置了一个简单的 If/Else 块来捕获错误。我通常会使用 Try/Catch，但我正在使用的 Exchange 2010 PS 环境不允许我使用大部分 Try/Catch 功能（而且我无法更新或以任何方式更改它，因为它是客户的系统，他们不愿意）。

问题是，当 Add-DistributionGroupMember cmdlet 设置为 -ErrorAction "Stop" 时，虽然代码将按预期运行，但它每次都会将错误输出到主机，这让客户（和我）很恼火，因为它是实际上只是红噪声，因为所有可能的错误都是通过详细的输出文件处理的。

如果我将 cmdlet 设置为 -ErrorAction "SilentlyContinue"，则会抑制错误文本，但不会像我预期的那样将错误添加到 $Error[0] 位置。 -ErrorAction "Ignore" 也是如此。该代码要求每次出现错误时将Error添加到$Error变量中。

代码如下：

$ListMembershipsIn | % {

        $Alias = $_.Alias
        $Member = $_.Member

        Add-DistributionGroupMember -Identity $Alias -Member $Member -Confirm:$false -ErrorAction Stop


        if($Error[0] -match "The recipient"){
            Write-Host -ForegroundColor Yellow "Already a member"
            Add-Content -Path $OutputPath -Value "$($Alias),$($Member),Group already contains Member"
        }
        elseif($Error[0] -match "couldn't be found"){
            Write-Host -ForegroundColor Yellow "not found"
            Add-Content -Path $OutputPath -Value "Group does not exist or cannot be found,$($Alias),N/A"
        }
        elseif($Error[0] -match "couldn't find"){
            Write-Host -ForegroundColor Yellow "not found"
            Add-Content -Path $OutputPath -Value "Member does not exist or cannot be found,$($Alias),$($Member)"
        }
        elseif($Error[0] -match "There are Multiple"){
            Add-Content -Path $OuputPath -Value "Member name matches too many recipient - Add Member Manually,$($Alias),$($Member)"
        }
        else{
            Add-Content -Path $OutputPath -Value "Member Successfully Added to Group,$($Alias),$($Member)"
            Write-Host -ForegroundColor Green "Throw Flag here"
        }
    }

Answer 1

您有两个追索选项，您可以利用-ErrorVariable 通用参数或Try/Catch 块与特定错误进行交互。

---

错误变量

在与ErrorVariable 交互时，您可以在名称前加上+ 来附加额外的错误，就像$Error 自动变量一样，例如：-ErrorVariable '+MyError'

$ListMembershipsIn | ForEach-Object {
    $Alias = $_.Alias
    $Member = $_.Member
    Add-DistributionGroupMember -Identity $Alias -Member $Member -ErrorVariable 'MyError'

    ## No error = good, continue the next iteration of the loop
    If (-not $MyError)
    {
        Add-Content -Path $OutputPath -Value "Member Successfully Added to Group,$Alias,$Member"
        Write-Host -ForegroundColor Green "Throw Flag here"
        Continue
    }

    Switch -Regex ($MyError.Exception.Message)
    {
        'The recipient'
        {
            Write-Host -ForegroundColor Yellow "Already a member"
            Add-Content -Path $OutputPath -Value "$Alias,$Member,Group already contains Member"
        }
        "couldn't be found"
        {
            Write-Host -ForegroundColor Yellow "not found"
            Add-Content -Path $OutputPath -Value "Group does not exist or cannot be found,$Alias,N/A"
        }
        "couldn't find"
        {
            Write-Host -ForegroundColor Yellow "not found"
            Add-Content -Path $OutputPath -Value "Member does not exist or cannot be found,$Alias,$Member"
        }
        'There are Multiple'
        {
            Add-Content -Path $OuputPath -Value "Member name matches too many recipient - Add Member Manually,$Alias,$Member"
        }
    }
}

---

尝试/抓住

$ListMembershipsIn | ForEach-Object {
    $Alias = $_.Alias
    $Member = $_.Member

    Try
    {
        Add-DistributionGroupMember -Identity $Alias -Member $Member -ErrorAction 'Stop'

        ## No error thrown = successful processing
        Add-Content -Path $OutputPath -Value "Member Successfully Added to Group,$Alias,$Member"
        Write-Host -ForegroundColor Green "Throw Flag here"
    }
    Catch
    {
        Switch -Regex ($_.Exception.Message)
        {
            'The recipient'
            {
                Write-Host -ForegroundColor Yellow "Already a member"
                Add-Content -Path $OutputPath -Value "$Alias,$Member,Group already contains Member"
            }
            "couldn't be found"
            {
                Write-Host -ForegroundColor Yellow "not found"
                Add-Content -Path $OutputPath -Value "Group does not exist or cannot be found,$Alias,N/A"
            }
            "couldn't find"
            {
                Write-Host -ForegroundColor Yellow "not found"
                Add-Content -Path $OutputPath -Value "Member does not exist or cannot be found,$Alias,$Member"
            }
            'There are Multiple'
            {
                Add-Content -Path $OuputPath -Value "Member name matches too many recipient - Add Member Manually,$Alias,$Member"
            }
        }
    }
}

Answer 2

使用“-ErrorAction Continue”这不会抑制错误，但会确保脚本继续运行并将错误放在 $Error 变量中。

您还可以使用 $Error.clear() 命令删除会话中存储的任何错误。