powershell - 如何扩展变量中的属性

Question

如果我去

$c = Resolve-DnsName facebook.com -Type TXT -Server '8.8.8.8'

当我输入 $c 我得到

Name                                     Type   TTL   Section    Strings
----                                     ----   ---   -------    -------
facebook.com                             TXT    7200  Answer     {v=spf1 redirect=_spf.facebook.com}        
facebook.com                             TXT    7200  Answer     {google-site-verification=A2WZWCNQHrGV_TW  
                                                                 wKh6KHY90tY0SHZo_RnyMJoDaG0s}
facebook.com                             TXT    7200  Answer     {google-site-verification=wdH5DTJTc9AYNwV  
                                                                 unSVFeK0hYDGUIEOGb-RReU6pJlY}

如何扩展 $c.strings ？

我知道我可以得到扩展的字符串并丢失其余的

Resolve-DnsName facebook.com -Type TXT -Server '8.8.8.8' | Select-Object -ExpandProperty strings

如何扩展整个答案？

Answer 1

您可以使用 calculated property将 Strings 属性 从 string[] 重新定义为 string:

Resolve-DnsName google.com -Type TXT -Server '8.8.8.8' |
    Select-Object Name, Type, TTL, Section, @{ N = 'Strings'; E = { [string] $_.Strings }} |
        Format-Table

这将导致:

Name         Type    TTL   Section   Strings           
----         ----    ---   -------   -------           
google.com    TXT   3600    Answer   docusign=05958488-....
google.com    TXT   3600    Answer   google-site-verifi....
google.com    TXT   3600    Answer   docusign=1b0a6754-....
google.com    TXT   3600    Answer   google-site-verifi....
google.com    TXT   3600    Answer   globalsign-smime-d....
google.com    TXT   3600    Answer   MS=E4A68B9AB2BB967....
google.com    TXT   3600    Answer   apple-domain-verif....
google.com    TXT   3600    Answer   v=spf1 include:_sp....
google.com    TXT   3600    Answer   facebook-domain-ve....

如果 Strings 属性中有多个字符串，使用上面的代码会将字符串与 $OFS (Out Field Separator) 连接起来。 , 默认为空格:

Name         Type    TTL   Section   Strings
----         ----    ---   -------   -------
google.com    TXT   3339    Answer   docusign=4752-4e...   docusign=4752-4e...

---

如果你想要一个多行字符串，你可以使用Out-String , 但是这需要先到 .Trim()输出并在 Format-Table 上使用 -Wrap才能正确显示。

使用硬编码值(docusign=05958488)的代码外观示例:

Resolve-DnsName google.com -Type TXT -Server '8.8.8.8' |
    Select-Object Name, Type, TTL, Section, @{
        Name       = 'Strings'
        Expression = { ('docusign=05958488', 'docusign=05958488' | Out-String).Trim() }
    } | Format-Table -Wrap

您也可以使用 -join operator用 CRLF (`r`n) 连接字符串以获得 多行字符串:

Resolve-DnsName google.com -Type TXT -Server '8.8.8.8' |
    Select-Object Name, Type, TTL, Section, @{
        Name       = 'Strings'
        Expression = { 'docusign=05958488', 'docusign=05958488' -join "`r`n" }
    } | Format-Table -Wrap

这两个例子的结果都是:

Name         Type    TTL   Section   Strings
----         ----    ---   -------   -------
google.com    TXT   3574    Answer   docusign=05958488
                                     docusign=05958488
google.com    TXT   3574    Answer   docusign=05958488
                                     docusign=05958488
google.com    TXT   3574    Answer   docusign=05958488
                                     docusign=05958488

---

如果您想要一种可以同时处理这两种情况的解决方案，Strings 只有一个值，而Strings 有多个值，您可以使用如下方式:

$result = Resolve-DnsName google.com -Type TXT -Server '8.8.8.8'
# Add random values to Strings for testing
$result.ForEach({ $_.Strings += Get-Random })
# Code logic
$result = foreach($element in $result) {
    $out = [ordered]@{
        Name    = $element.Name
        Type    = $element.Type
        TTL     = $element.TTL
        Section = $element.Section
    }

    foreach($e in $element.Strings) {
        $out.Strings = $e
        # output one object per string
        [pscustomobject] $out
    }
}

$result | Format-Table

上述逻辑将创建一个新对象Strings 属性中的每个元素。输出将是:

TTL   Section  Name       Type   Strings
---   -------  ----       ----   -------
3444  Answer   google.com  TXT   apple-domain-verificatio...
3444  Answer   google.com  TXT   1419241945              
3444  Answer   google.com  TXT   MS=E4A68B9AB2BB9670BCE15...
3444  Answer   google.com  TXT   463070462               
3444  Answer   google.com  TXT   facebook-domain-verifica...
3444  Answer   google.com  TXT   958788674               
3444  Answer   google.com  TXT   google-site-verification...
3444  Answer   google.com  TXT   1623605637