如何在Powershell中已匹配的行之后選擇第一條匹配的行？

Question

我正在嘗試使用powershell從powercfg的輸出查詢一些Windows電源設置。 我有足夠的信息來將范圍縮小到一組子設置，但是在文本塊中，我仍然需要使用GUID查找匹配的設置，然后需要提取該設置的當前設置值。 我能夠使用Select-String -Context實現此Select-String -Context ，但是它不是動態的，因此容易出錯。 我正在尋找一種更干凈的方法來提取價值。

這是我擁有的文本塊的一個示例（存儲在$block ）：

Power Scheme GUID: 381b4222-f694-41f0-9685-ff5bb260df2e  (Balanced)
  GUID Alias: SCHEME_BALANCED
  Subgroup GUID: 238c9fa8-0aad-41ed-83f4-97be242c8f20  (Sleep)
    GUID Alias: SUB_SLEEP
    Power Setting GUID: 29f6c1db-86da-48c5-9fdb-f2b67b1f44da  (Sleep after)
      GUID Alias: STANDBYIDLE
      Minimum Possible Setting: 0x00000000
      Maximum Possible Setting: 0xffffffff
      Possible Settings increment: 0x00000001
      Possible Settings units: Seconds
    Current AC Power Setting Index: 0x00000708
    Current DC Power Setting Index: 0x00000384

    Power Setting GUID: 94ac6d29-73ce-41a6-809f-6363ba21b47e  (Allow hybrid sleep)
      GUID Alias: HYBRIDSLEEP
      Possible Setting Index: 000
      Possible Setting Friendly Name: Off
      Possible Setting Index: 001
      Possible Setting Friendly Name: On
    Current AC Power Setting Index: 0x00000001
    Current DC Power Setting Index: 0x00000001

    Power Setting GUID: 9d7815a6-7ee4-497e-8888-515a05f02364  (Hibernate after)
      GUID Alias: HIBERNATEIDLE
      Minimum Possible Setting: 0x00000000
      Maximum Possible Setting: 0xffffffff
      Possible Settings increment: 0x00000001
      Possible Settings units: Seconds
    Current AC Power Setting Index: 0x00002a30
    Current DC Power Setting Index: 0x00002a30

    Power Setting GUID: bd3b718a-0680-4d9d-8ab2-e1d2b4ac806d  (Allow wake timers)
      GUID Alias: RTCWAKE
      Possible Setting Index: 000
      Possible Setting Friendly Name: Disable
      Possible Setting Index: 001
      Possible Setting Friendly Name: Enable
      Possible Setting Index: 002
      Possible Setting Friendly Name: Important Wake Timers Only
    Current AC Power Setting Index: 0x00000001
    Current DC Power Setting Index: 0x00000001

假設我要提取“ Allow hybrid sleep的AC值，在這種情況下為0x00000001 。 我可以將setting_guid插入查詢字符串中。

現在，我正在使用這段代碼來動態提取特定設置的值：

$block = powercfg /q #{scheme_guid} #{sub_guid}
$setting = $block | Select-String -Pattern #{setting_guid} -Context 0, 8 | %{$_.Context.PostContext}
$line = $setting | Select-String -Pattern 'Current #{ac_or_dc} Power Setting Index'
$line -match 'Current #{ac_or_dc} Power Setting Index: (?<value>0x.{8})'
Write-Output ([int]$matches['value'])

-Context 0, 8可以正常工作，但是硬編碼的-Context 0, 8並不是真正可取的，因為有時塊可能真的很短或很長，而我的查詢將無法提取值或從錯誤的行中檢索。 我希望找到一種更清潔的方式來做到這一點，最好是程序化且易於閱讀（只要有意義就可以使用正則表達式 ）。

Answer 1

如果我們希望使用正則表達式執行此任務，則可能需要以傳遞換行符的表達式開始，類似於以下內容：

Allow hybrid sleep[\s\S]+?Current DC Power Setting Index:\s+(.+)\s
Allow hybrid sleep[\s\S]+?Current DC Power Setting Index:\s+(.+)
Allow hybrid sleep[\w\W]+?Current DC Power Setting Index:\s+(.+)\s
Allow hybrid sleep[\d\D]+?Current DC Power Setting Index:\s+(.+)

我們期望的輸出將在此捕獲組中： (.+) 。

演示版

正則表達式

如果不需要此表達式，並且希望對其進行修改，請訪問此鏈接regex101.com 。

RegEx電路

jex.im可視化正則表達式：

Answer 2

這樣吧...

$PowerData = @'
Power Scheme GUID: 381b4222-f694-41f0-9685-ff5bb260df2e  (Balanced)
  GUID Alias: SCHEME_BALANCED
  Subgroup GUID: 238c9fa8-0aad-41ed-83f4-97be242c8f20  (Sleep)
    GUID Alias: SUB_SLEEP
    Power Setting GUID: 29f6c1db-86da-48c5-9fdb-f2b67b1f44da  (Sleep after)
      GUID Alias: STANDBYIDLE
      Minimum Possible Setting: 0x00000000
      Maximum Possible Setting: 0xffffffff
      Possible Settings increment: 0x00000001
      Possible Settings units: Seconds
    Current AC Power Setting Index: 0x00000708
    Current DC Power Setting Index: 0x00000384

    Power Setting GUID: 94ac6d29-73ce-41a6-809f-6363ba21b47e  (Allow hybrid sleep)
      GUID Alias: HYBRIDSLEEP
      Possible Setting Index: 000
      Possible Setting Friendly Name: Off
      Possible Setting Index: 001
      Possible Setting Friendly Name: On
    Current AC Power Setting Index: 0x00000001
    Current DC Power Setting Index: 0x00000001

    Power Setting GUID: 9d7815a6-7ee4-497e-8888-515a05f02364  (Hibernate after)
      GUID Alias: HIBERNATEIDLE
      Minimum Possible Setting: 0x00000000
      Maximum Possible Setting: 0xffffffff
      Possible Settings increment: 0x00000001
      Possible Settings units: Seconds
    Current AC Power Setting Index: 0x00002a30
    Current DC Power Setting Index: 0x00002a30

    Power Setting GUID: bd3b718a-0680-4d9d-8ab2-e1d2b4ac806d  (Allow wake timers)
      GUID Alias: RTCWAKE
      Possible Setting Index: 000
      Possible Setting Friendly Name: Disable
      Possible Setting Index: 001
      Possible Setting Friendly Name: Enable
      Possible Setting Index: 002
      Possible Setting Friendly Name: Important Wake Timers Only
    Current AC Power Setting Index: 0x00000001
    Current DC Power Setting Index: 0x00000001
'@ 

[regex]::Matches($PowerData,'(?s)hybrid.*?DC').Value | 
ForEach {[regex]::Matches($PSitem,'Current AC Power Setting Index.*').Value}

# Results

Current AC Power Setting Index: 0x00000001

要么

Clear-Host; (((Get-Content -Path '.\PowerDataTemplate.txt')) -match 'hybrid|AC')#[3]

<#
Current AC Power Setting Index: 0x00000708
Power Setting GUID: 94ac6d29-73ce-41a6-809f-6363ba21b47e  (Allow hybrid sleep)
    GUID Alias: HYBRIDSLEEP
Current AC Power Setting Index: 0x00000001
Current AC Power Setting Index: 0x00002a30
Power Setting GUID: bd3b718a-0680-4d9d-8ab2-e1d2b4ac806d  (Allow wake timers)
Current AC Power Setting Index: 0x00000001
#>

Clear-Host; (((Get-Content -Path '.\PowerDataTemplate.txt')) -match 'hybrid|AC')[3]
# Current AC Power Setting Index: 0x00000001

Clear-Host; [regex]::matches($(Get-Content -Path 'variable:\PowerData'),'.*hybrid.*|.*AC.*').Value

<#
Current AC Power Setting Index: 0x00000708
Power Setting GUID: 94ac6d29-73ce-41a6-809f-6363ba21b47e  (Allow hybrid sleep)
Current AC Power Setting Index: 0x00000001
Current AC Power Setting Index: 0x00002a30
Current AC Power Setting Index: 0x00000001
#>


Clear-Host; [regex]::matches($(Get-Content -Path 'variable:\PowerData'),'.*hybrid.*|.*AC.*').Value[2]
# Current AC Power Setting Index: 0x00000001

或者在PowerShellv5x中，可以使用具有字符串轉換模板的ConvertFrom-String或ConvertFrom-StringData cmdlet。

https://docs.microsoft.com/zh-cn/powershell/module/microsoft.powershell.utility/convertfrom-stringdata?view=powershell-6

https://docs.microsoft.com/zh-cn/powershell/module/microsoft.powershell.utility/convertfrom-string?view=powershell-5.1

更新OP

我對此進行了更多介紹，如果您所追求的只是一個特定的設置，那為什么不直接要求它呢。 例如。

# Get only (Allow hybrid sleep)
powercfg.exe query SCHEME_MIN SUB_SLEEP HYBRIDSLEEP

# Get only the AC setting
(powercfg.exe query SCHEME_MIN SUB_SLEEP HYBRIDSLEEP) -match 'Current AC Power Setting Index'

 # Results
 Current AC Power Setting Index: 0x00000000