powershell - 递归函数行为不正确

Question

我们在组成员的事件目录中具有以下结构:

BEL Test Top level
    - BEL Test Sub  level 1
        - Bob
        - BEL Test Sub  level 1.1
            - Jake
            - Mike
    - BEL Test Sub  level 2
        - BEL Test Sub  level 2.1

所需的输出:

GroupName : BEL Test Top level
Member1   : BEL Test Sub  level 1
Member2   : BEL Test Sub  level 1.1
Member3   : Jake

GroupName : BEL Test Top level
Member1   : BEL Test Sub  level 1
Member2   : BEL Test Sub  level 1.1
Member3   : Mike

GroupName : BEL Test Top level
Member1   : BEL Test Sub  level 1
Member2   : Bob

GroupName : BEL Test Top level
Member1   : BEL Test Sub  level 2
Member2   : BEL Test Sub  level 2.1

因此，对于每个最深的对象，都需要有一个 [PSCustomObject]作为输出。我不是递归函数方面的专家，但是我编写的以下代码非常接近:

$Name = 'BEL Test Top level'

$hash = $null

Function Add-MemberGroupHC {
    Param (
        [Parameter(Mandatory, ValueFromPipeline)]
        $Identity,
        $Past,
        [Int]$Level
    )

    Begin {
        if (-not $Level) {
            $Level = 0
        }

        if (-not $Past) {
            $Past = [Ordered]@{
                GroupName = $Name
            }
        }

        if ($Identity.GetType().Name -ne 'ADPrincipal') {
            $Identity = Get-ADGroup -Identity $Identity
        }
    }

    Process {
        $Level++

        Write-Verbose "Check members '$($Identity.Name)'"

        $Members = Get-ADGroupMember $Identity 

        $Members | ForEach-Object {
            Write-Verbose "Add property '$('Member' + $Level)' value '$($_.Name)'"
            $Past.('Member' + $Level) = $_.Name

            if (($_.ObjectClass -eq 'User') -or (-not (Get-ADGroupMember $_))) {
                  [PSCustomObject]$Past
            }
                $Past.('Member' + $Level) = $_.Name
                [PSCustomObject]$Past
            }

            if ($_.ObjectClass -eq 'Group') {
                Add-MemberGroupHC -Identity $_ -Past $Past -Level $Level
            }
        }

    }
}

$Result = Add-MemberGroupHC $Name
$Result | fl *

在没有 child 的情况下调用自己时，它怎么可能只输出最深的层次？

Answer 1

我想采用自己的方法从一开始就了解它是如何工作的。我不能说这是否比您预期的方法更好或更差。希望您可以使用它来查看您可能出错的地方。

Function Get-HighestMemberKey{
    param([hashtable]$HashTable)

    # Collect all of the member# names. Find the highest one. 
    # If one does not exist null gets cast to 0 with [int]
    return [int](($HashTable.GetEnumerator()) | 
        Select -ExpandProperty Name | 
        Where-Object{$_ -match "(\d+)$"} |
        ForEach-Object{$Matches[0]} |
        Measure-Object -Maximum | 
        Select -ExpandProperty Maximum)
}

function Get-ADMembersGroupChain{
    param(
        $GroupName,
        $CurrentChain
    )

    $CurrentMembers = @(Get-ADGroupMember $GroupName)

    # Check if this group has any members.
    if($CurrentMembers.Count -gt 0){
        # If there are any groups process them individually
        $CurrentMembers | ForEach-Object{

            if(!$CurrentChain){
                # This is a root group. Start a new chain.
                $CurrentChain = @{GroupName=$GroupName}
            }

            # Add this member to the chain. 
            # Create a new chain for this pass. Use clone to ensure we are working with a new chain. 
            $nextMemberIndex = (Get-HighestMemberKey $CurrentChain) + 1
            $newChain = $CurrentChain.Clone()
            $newChain."Member$nextMemberIndex" = $_.Name

            # If this is a group continue the chain. 
            if($_.ObjectClass -eq "group"){
                Get-ADMembersGroupChain -GroupName $_.SamAccountName -CurrentChain $newChain
            } else {
                # This is a user. Output the chain
                [pscustomobject]$newChain
            }
        }
    } else {
        # The group is already part of the chain. Ouput as is. 
        [pscustomobject]$CurrentChain
    }
}

$chains = Get-ADMembersGroupChain "BEL Test Top level" 
$chains | ForEach-Object{$_| fl}

我们在这里所做的是构建以递归方式传递给函数的哈希表。当遇到一个组时，再次调用该函数。如果曾经有一个包含 0 个成员的组，或者如果找到一个用户，则到目前为止的链将转换为 psobject 并沿管道发送。

这样做有一个小的副作用，因为您无法保证成员显示的顺序。如果这是一个问题，您将看到为此构建自己的选择语句。

样本输出

GroupName : BEL Test Top level
Member3   : Jake
Member1   : BEL Test Sub  level 1
Member2   : BEL Test Sub  level 1.1

GroupName : BEL Test Top level
Member3   : Mike
Member1   : BEL Test Sub  level 1
Member2   : BEL Test Sub  level 1.1

GroupName : BEL Test Top level
Member1   : BEL Test Sub  level 1
Member2   : Bob

GroupName : BEL Test Top level
Member1   : BEL Test Sub  level 2
Member2   : BEL Test Sub  level 2.1

不使用 Format-List ，就像您所做的那样，输出可能看起来不正确，因为 PowerShell 将根据管道中的第一个对象显示，但所有属性都将在那里。如果这是一个问题，那么您需要创建一个小函数来保证属性输出的顺序。一个基本的例子是:

function Order-Chain{
    param(
        $chain
    )

    # Take the group and members and ensure the are output in numerical order. 
    # Assume there is at least a property called GroupName
    $properties = @("GroupName")
    # Get all the remaining property names minus the first one.
    $properties += $chain.psobject.properties.name | Where-Object{$_ -notin $properties} | 
        # Sort the property list on the number at the end of the property name
        Sort-Object -Property {[void]($_ -match "\d+$");$matches[0]}

    # Order the chain and send down the pipe
    $chain | Select-Object $properties
} 

这将创建一个排序的属性列表，该列表被馈送到 Select-Object。 .它可能看起来更智能/更易于使用 [ordered]创建哈希表时，但您无法克隆有序哈希，所以这就是我解决它的方法。

这里的所有功能都可以变得更加健壮，即使用 begin像你一样阻止，并进入高级功能，但现在可以正常运行。 当心 循环组，因为没有逻辑可以检测到这些。