如何比较PowerShell中的两个查询

Question

你好，我是新来的PowerShell和编码本身。我的任务是创建一个PowerShell脚本，它执行以下操作

1. 检查IIS是否已安装。如果未安装IIS，则会在服务器上暂停IIS (非常容易)。
2. 如果安装了IIS，则它将角色服务与所需角色服务的列表相匹配，并安装缺少的角色服务。

到目前为止，我已经编写了以下代码：

Set-ExecutionPolicy Bypass -Scope Process
$IISFeatures = "Web-WebServer","Web-Common-Http","Web-Default-Doc","Web-Dir-Browsing","Web-Http-Errors","Web-Static-Content","Web-Http-Redirect","Web-Health","Web-Http-Logging","Web-Custom-Logging","Web-Log-Libraries","Web-ODBC-Logging","Web-Request-Monitor","Web-Http-Tracing","Web-Performance","Web-Stat-Compression","Web-Dyn-Compression","Web-Security","Web-Filtering","Web-Basic-Auth","Web-CertProvider","Web-Client-Auth","Web-Digest-Auth","Web-Cert-Auth","Web-IP-Security","Web-Url-Auth","Web-Windows-Auth","Web-App-Dev","Web-Net-Ext","Web-Net-Ext45","Web-AppInit","Web-Asp-Net","Web-Asp-Net45","Web-CGI","Web-ISAPI-Ext","Web-ISAPI-Filter","Web-Includes","Web-Mgmt-Tools","Web-Mgmt-Console","Web-Scripting-Tools","Web-Mgmt-Service"
$b = Get-WindowsFeature web* | Where-Object {$_.InstallState -eq 'Available'}

function InstallIIS()
{

    Install-WindowsFeature -Name $IISFeatures
}

function VerifyAndInstallRoleServices()
{

}

Write-Host "`nWelcome to  prerequisite installation PowerShell Script. `n`nWe will now conitnue with the installation of prerequisites`n" 
$machinename = hostname
Write-Host "Verifying IIS Role and Role services`n"

if ((Get-WindowsFeature Web-Server).InstallState -eq "Installed") {
    Write-Host "IIS is installed on $machinename`n"
} 
else {
    Write-Host "IIS is not installed on $machinename`n"
    $a = Read-Host -Prompt "Press 'Y' if you want this script to install IIS for you"
    if ($a -eq 'Y') {Write-Host "IIS is being installed now"}
    InstallIIS 
}

我想要一个将$b和$IISFeatures进行比较的代码，它将首先列出缺少的特性，然后在用户提示后安装所需的特性，如果已经安装了所有所需的羽毛，则继续编写代码。

知道我会怎么做吗？

Answer 1

要做到这一点，有几种方法。一种方法是使用Compare-Object列出这些差异。

Compare-Object -ReferenceObject $b -DifferenceObject $IISFeatures -IncludeEqual

另一种方法是循环遍历$IISFeatures并查看$b中的值是否在其中。

$featureNameList = $b.Name
foreach ($iisFeature in $IISFeatures) {
    if ($iisFeature -notin $featureNameList){
        Write-Output $iisFeature
    }
}

这将输出$IISFeatures列表中所有不在$b中已安装的特性中的特性。