有人能为Powershell优化我的.net RegEx吗？？解析一个有错误的表吗？

Question

目前，我正试图从Microsoft (其GitHub版本)解析一个表，以获得适当的PowerShell对象。我将共享相关的代码部分，以便您可以测试它。它确实解析了我想要的东西，但是我希望结果已经被修剪了(没有前导的尾随空格或换行)。我还必须得到"CNG键隔离“的结果，它具有不同的格式。仅对于该数据块，我的RegEx包含换行，而我没有让它正常工作。我知道我可以在PowerShell中完成RegEx之后的一些解析，但是我希望能够更好地使用RegEx。

我尚未优化的RegEx如下所示

(?:^##\s*(?<ServiceTitle>[^\r\n#]*)[\r\n\s]*\|\s+Name\s+\|\s+Description\s+\|(?:[\r\n\s\|\-\*]+Service name[\|\*\s]+(?<ServiceName>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Description[\|\*\s]+(?<Description>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Installation[\|\*\s]+(?<Installation>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Startup type[\|\*\s]+(?<StartupType>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Recommendation[\|\*\s]+(?<Recommendation>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Comments[\|\*\s]+(?<Comments>[^\|]*?)(?: ?\|))*)

您可以在这里测试它：https://regex101.com/r/xQDRCO/1

要解析的数据来自：https://raw.githubusercontent.com/MicrosoftDocs/windowsserverdocs/main/WindowsServerDocs/security/windows-services/security-guidelines-for-disabling-system-services-in-windows-server.md

它基本上应该为每个服务获取一个数据块，并尝试获取

"ServiceTitle","ServiceName","Description","Installation","StartupType","Recommendation","Comments"

不管他们是什么顺序，或者他们中的一个失踪了。"ServiceTitle"是一种特殊的东西，必须在那里。

下面是我目前测试的PowerShell代码：

$fields = "ServiceTitle","ServiceName","Description","Installation","StartupType","Recommendation","Comments"
$RequestData = Invoke-WebRequest -UseBasicParsing -Uri https://raw.githubusercontent.com/MicrosoftDocs/windowsserverdocs/main/WindowsServerDocs/security/windows-services/security-guidelines-for-disabling-system-services-in-windows-server.md
$RegExMatches = [Regex]::Matches($RequestData.content,'(?:^##\s*(?<ServiceTitle>[^\r\n#]*)[\r\n\s]*\|\s+Name\s+\|\s+Description\s+\|(?:[\r\n\s\|\-\*]+Service name[\|\*\s]+(?<ServiceName>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Description[\|\*\s]+(?<Description>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Installation[\|\*\s]+(?<Installation>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Startup type[\|\*\s]+(?<StartupType>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Recommendation[\|\*\s]+(?<Recommendation>[^\|]*?)(?: ?\|)|[\r\n\s\|\-\*]+Comments[\|\*\s]+(?<Comments>[^\|]*?)(?: ?\|))*)',[System.Text.RegularExpressions.RegexOptions]::Multiline)
$FullList = @()
foreach ($entry in $RegExMatches) {$ServiceAsObject = [pscustomobject]@{};foreach ($field in $fields) {$ServiceAsObject | Add-Member -MemberType NoteProperty -Name $field -Value $entry.Groups[$field].value};$FullList += $ServiceAsObject}
$FullList[15..17] # three items to see what problem i have with "CNG Key Isolation"

我不会经常使用更大的RegEx，所以可以随意给我一些反馈来提高自己。

谢谢你，安迪尔

Answer 1

这可能不是您想要的，但您可以执行如下操作来输出自定义对象的数组：

$output = switch -regex ($requestdata.content -split '\r?\n') {
    '^##\s' {
        # tracking empty lines since there is one under the service title
        # start new hash table when a new service is found
        # remove ## from service title names
        $emptyLineCount = 0
        $hash = [ordered]@{}
        $hash.ServiceTitle = $_ -replace '^##\s'
    }
    '\| \*\*' {
        # split on | and surrounding spaces
        # replace ** so name is cleaner
        if ($hash.ServiceTitle) {
            $key,$value = ($_ -split '\s*\|\s*' -replace '\*\*')[1,2]
            $hash[$key] = $value
        }
    }
    '^$' {
        # when second empty line is reached in a service block, output object
        if ($hash.ServiceTitle -and ++$emptyLineCount -eq 2) {
            [pscustomobject]$hash
        }
    }
}

# Finding a service by title
$output | Where ServiceTitle -eq 'CNG Key Isolation'

拆分内容会形成一个行数组，这对我来说更容易使用switch语句。

如果存在数据不一致，使用更纯的regex解决方案将使事情变得更加脆弱。用于CNG密钥隔离的数据块在每一行的末尾都缺少|，并且是唯一这样的数据块。因此，现在您必须匹配特例或修复数据。

$fields = "ServiceTitle","ServiceName","Description","Installation","StartupType","Recommendation","Comments"
$RequestData = Invoke-WebRequest -UseBasicParsing -Uri https://raw.githubusercontent.com/MicrosoftDocs/windowsserverdocs/main/WindowsServerDocs/security/windows-services/security-guidelines-for-disabling-system-services-in-windows-server.md
$regexString = '(?m)^##\s(?<ServiceTitle>.*)$(?s).*?\*\*Service name\*\* \| (?<ServiceName>.*?(?=\s+\|)).*?\*\*Description\*\* \| (?<Description>.*?(?=\s+\|)).*?\*\*Installation\*\* \| (?<Installation>.*?(?=\s+\|)).*?\*\*Startup type\*\* \| (?<StartupType>.*?(?=\s+\|)).*?\*\*Recommendation\*\* \| (?<Recommendation>.*?(?=\s+\|)).*?\*\*Comments\*\* \| (?<Comments>.*?(?=\s+\|))'
$out = $RequestData.Content |
    Select-String -Pattern $regexString -AllMatches |
        Foreach-Object { $_.Matches | Foreach-Object {
            $hash = [ordered]@{}
            foreach ($field in $fields) {
                $hash.$field = $_.Groups.where{$_.Name -eq $field}.Value}
                [pscustomobject]$hash
            }
        }

Answer 2

假设您的$RequestData.content中有所有的文本，那么我不会尝试创建一个大型regex来将其解析为可用的对象，而是这样做：

# first split the tables from the rest of the text and work on the table lines only
$result = ($RequestData.content -split '(?m)^The following tables.*:')[-1].Trim() -split '(?m)^## ' | 
    Where-Object { $_ -match '\S' } |
    ForEach-Object {
        # split each block to parse out the title and the table data
        $title, $table = ($_.Trim() -split '(\r?\n){2}', 2).Trim()
        # now remove the markdown stuff from the data and convert it using ConvertFrom-Csv
        $data = (($table -replace '(?m)^\|--\|--\||[*]{2}|^\||\|$' -replace '\s\|\s', '|') -split '\r?\n' -ne '').Trim()  | ConvertFrom-Csv -Delimiter '|'
        # set up an ordered Hashtable to store the data
        $hash = [ordered]@{ServiceTitle = $title}
        foreach ($item in $data) {
            $hash[$item.Name] = $item.Description
        }
        # output real objects
        [PsCustomObject]$hash
    }

$result