写入信息不显示在开始转录的文件中。

Question

我正在使用PowerShell 5.1，并试图确定为什么Write-Information消息不显示在Start-Transcript创建的记录日志中，除非我将$InformationPreference设置为SilentlyContinue。我希望在控制台中显示这些消息，并将它们写入日志文件。

我在这里看了看：variables?view=powershell-5.1#informationpreference

然后，我决定创建这个脚本来测试所编写的内容以及编写的时间。请参阅Testing explicit behavior with transcripts -------------下面的首选项部分

Clear-Host

$ErrorActionPreference = "Stop"

try {
    Write-Host "Starting transcript"
    Start-Transcript -Force -Path "$PSScriptRoot\default.txt"

    <#
        In PowerShell 5.1 the default behavior is as follows:
            $DebugPreference       = SilentlyContinue
            $InformationPreference = SilentlyContinue
            $ProgressPreference    = Continue
            $VerbosePreference     = SilentlyContinue

        See the following for more information:
        https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_preference_variables?view=powershell-5.1
    #>

    # I am not testing Write-Output as I am not worried about programmatic/pipeline stuff, just contextual messages for end-users or logging

    Write-Host "`nTesting default behavior with transcripts --------------------------------`n"

    # Setting these just in case I launch this script in a session where a previous script might have modified the preference variables
    $DebugPreference = "SilentlyContinue"
    $InformationPreference = "SilentlyContinue"
    $ProgressPreference = "Continue"
    $VerbosePreference = "SilentlyContinue"

    Write-Host "Calling Write-Host"
    Write-Debug "Calling Write-Debug"
    Write-Error "Calling Write-Error" -ErrorAction "Continue"
    Write-Information "Calling Write-Information"
    Write-Progress "Calling Write-Progress"
    Write-Verbose "Calling Write-Verbose"

    Stop-Transcript
    Start-Transcript -Force -Path "$PSScriptRoot\everything_continue.txt"

    Write-Host "`nTesting explicit behavior with transcripts --------------------------------`n"

    # Turn everything on
    $DebugPreference = "Continue"
    $InformationPreference = "Continue" # Setting this to SilentlyContinue makes it show up in the log but not the console. Setting this to 'Continue' makes it show up in the console but not the log.
    $ProgressPreference = "Continue"
    $VerbosePreference = "Continue"

    Write-Host "Calling Write-Host"
    Write-Debug "Calling Write-Debug"
    Write-Error "Calling Write-Error" -ErrorAction "Continue"
    Write-Information "Calling Write-Information"
    Write-Progress "Calling Write-Progress"
    Write-Verbose "Calling Write-Verbose"

    Stop-Transcript

    Write-Host "`nResults -------------------------------------------------------------------`n"

    # See what actually gets captured and written by the transcriber

    $messageTypes = @("Write-Debug", "Write-Error", "Write-Host", "Write-Information", "Write-Verbose")

    Write-Host "Default" -ForegroundColor Cyan
    $lines = Get-Content "$PSScriptRoot\default.txt"
    foreach ($message in $messageTypes) {
        if ($lines -like "*Calling $message*") {
            Write-Host "  $message PRESENT" -ForegroundColor Green
        }
        else {
            Write-Host "  $message MISSING" -ForegroundColor Red
        }
    }

    Write-Host "Everything Continue" -ForegroundColor Cyan
    $lines = Get-Content "$PSScriptRoot\everything_continue.txt"
    foreach ($message in $messageTypes) {
        if ($lines -like "*Calling $message*") {
            Write-Host "  $message PRESENT" -ForegroundColor Green
        }
        else {
            Write-Host "  $message MISSING" -ForegroundColor Red
        }
    }
}
catch {
    Write-Host "----------------------------------------------------------------------------------------------------"
    Write-Host $_.Exception
    Write-Host $_.ScriptStackTrace
    Write-Host "----------------------------------------------------------------------------------------------------"

    try { Stop-Transcript } catch { }

    throw $_
}

Answer 1

您所看到的是bug in PowerShell PowerShell ( v5.1.17134.590)，它已在PowerShell Core中修复(至少v6.1.0 --尽管其他与抄本相关的问题仍然存在；请参见这个GitHub问题)。

我鼓励您在Windows PowerShell UserVoice论坛上报告它(请注意，PowerShell GitHub-repo 问题论坛只针对PowerShell Core中也存在的错误)。

下面是如何验证该bug是否存在于PowerShell版本中的PowerShell：

使用下面的代码创建一个脚本并运行它：

'--- Direct output'

$null = Start-Transcript ($tempFile = [io.path]::GetTempFileName())

    # Note that 'SilentlyContinue' is also the default value.
    $InformationPreference = 'SilentlyContinue'

    # Produces no output.
    Write-Information '1-information' 

    # Prints '2-Information' to the console.
    Write-Information '2-information' -InformationAction Continue

$null = Stop-Transcript

'--- Write-Information output transcribed:'

Select-String '-information' $tempFile | Select-Object -ExpandProperty Line

Remove-Item $tempFile

有了bug (Windows PowerShell)，您将看到：

--- Direct output
2-information
--- Write-Information output transcribed:
INFO: 1-information

也就是说，与预期行为相反的发生了：该记录记录了它不应该拥有的调用(因为它没有产生输出)，并且没有记录它应该拥有的调用。

此外，日志记录的输出以INFO:作为前缀，这也是PowerShell核心中的一个不一致之处。

除了在希望记录在记录记录中的输出的情况下使用Write-Host调用以外，没有完整的解决办法，但是不管首选项变量$InformationPreference的值如何，都会被记录为( Write-Host正式提供了-InformationAction公共参数，但被忽略了)。

修复了bug (PowerShell核心)之后，您将看到：

--- Direct output
2-information
--- Write-Information output transcribed:
2-information

成绩单现在与直接输出一致。