写入信息不会显示在Start-Transcript转录的文件中

Question

我正在使用PowerShell 5.1，我试图确定为什么Write-Information消息没有显示在Start-Transcript创建的脚本日志中，除非我将$InformationPreference设置为SilentlyContinue。我想在控制台中显示消息并将它们写入日志文件。

我看了看这里：https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_preference_variables?view=powershell-5.1#informationpreference

然后我决定创建这个脚本来测试写入的内容和时间。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://docs.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Windows PowerShell中的一个错误（自v5.1.17134.590起）已在PowerShell Core中修复（至少从v6.1.0开始 - 尽管其他与转录相关的问题仍然存在;请参阅this GitHub issue）。

我建议您在Windows PowerShell UserVoice论坛中报告它（请注意，PowerShell GitHub-repo issues forum仅用于PowerShell Core中也存在的错误）。

以下是验证PowerShell版本中是否存在该错误的方法：

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

---

有了这个bug（Windows PowerShell），你会看到：

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

也就是说，发生了与预期行为相反的情况：成绩单记录了它不应该具有的调用（因为它没有产生输出），并且它没有记录它应该具有的那个。

此外，记录的输出前缀为INFO: ，这是一个不一致的问题，也已在PowerShell Core中修复。

没有完整的解决方法，除了您可以使用Write-Host调用，如果您希望输出记录在记录中 - 但这些调用将无条件记录，而不管首选变量$InformationPreference的值（而Write-Host正式提供-InformationAction常见参数，它被忽略）。

---

修复了错误（PowerShell Core）后，您会看到：

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

成绩单现在与直接输出一致。