powershell - 格式差异

Question

我有两个代码块：

$allUsers = Get-ADUser -Filter *
foreach($_ in $allUsers.Name){
    Write-Host "User $_ is member of the following groups:" -for Yellow
    Get-ADPrincipalGroupMembership -Identity $_ | select Name,objectClass,Groupscope,Groupcategory | sort Name | Format-Table
}
User Administrator is member of the following groups:

Name                 objectClass                  Groupscope       Groupcategory
----                 -----------                  ----------       -------------
Administrators       group                       DomainLocal            Security
Distributed COM U... group                       DomainLocal            Security
Domain Admins        group                            Global            Security
Domain Users         group                            Global            Security
Enterprise Admins    group                         Universal            Security
Group Policy Crea... group                            Global            Security
HelpLibraryUpdaters  group                       DomainLocal            Security
Schema Admins        group                         Universal            Security


User Guest is member of the following groups:

Name                 objectClass                  Groupscope       Groupcategory
----                 -----------                  ----------       -------------
Domain Guests        group                            Global            Security
Guests               group                       DomainLocal            Security

另一个版本如下所示：

    $allUsers = Get-ADUser -Filter *
    foreach($_ in $allUsers.Name){
        Write-Host "User $_ is member of the following groups:"
        Get-ADPrincipalGroupMembership -Identity $_ | select Name,objectClass,Groupscope,Groupcategory | sort Name
    }

User Administrator is member of the following groups:

Name                 objectClass                  Groupscope       Groupcategory
----                 -----------                  ----------       -------------
Administrators       group                       DomainLocal            Security
Distributed COM U... group                       DomainLocal            Security
Domain Admins        group                            Global            Security
Domain Users         group                            Global            Security
Enterprise Admins    group                         Universal            Security
Group Policy Crea... group                            Global            Security
HelpLibraryUpdaters  group                       DomainLocal            Security
Schema Admins        group                         Universal            Security
User Guest is member of the following groups:
Domain Guests        group                            Global            Security
Guests               group                       DomainLocal            Security

在我看来，后者更容易阅读。我的问题是这是；为什么第一个代码块显示每个用户的标题？在我看来，选择对象是为 $allUsers.Name 中的每个用户调用的，所以标题应该每次都在后一个中显示？

Answer 1

Format-Table不同的是被调用的次数。在第一个示例中，它为每个用户调用。这意味着为每个用户打印标题。在第二个示例Format-Table中，仅调用一次，因此标题仅打印一次。

第二个命令Format-Table最后有一个暗示，所以如果你这样做：

$allUsers = Get-ADUser -Filter *
foreach($_ in $allUsers.Name){
    Write-Host "User $_ is member of the following groups:"
    Get-ADPrincipalGroupMembership -Identity $_ | select Name,objectClass,Groupscope,Groupcategory | sort Name
} | Format-Table 

你应该得到相同的结果。