update-mvpsHosts.ps1

#Requires -RunAsAdministrator
Add-Type -AssemblyName System.IO.Compression.FileSystem
function Unzip {
    param([string]$zipfile, [string]$outpath)

    [System.IO.Compression.ZipFile]::ExtractToDirectory($zipfile, $outpath)
}

function UpdateHost {
    param([string]$hostFilePath, [string[]]$mvpsFileContents)
    $hostFileContents = Get-Content -Path $hostFilePath

    $count = 0;
    foreach($hostLine in $hostFileContents)
    {
        if ($hostLine -eq "# This MVPS HOSTS file is a free download from:            #") {
            break
        }
        $count++
    }

    $finalHostFileContents = $hostFileContents[0..$($count-1)] + $mvpsFileContents
    Set-Content -Path $hostFilePath -value $finalHostFileContents
    Write-Host "Done: Local Host file updated" 
}

$basePath = "$env:windir\system32\drivers\etc"
$mvpsHostZipFilePath = "$basePath\mvps.zip"
if (Test-Path("$mvpsHostZipFilePath")) { Remove-Item $mvpsHostZipFilePath -Force }
$mvpsHostUnzipFolderPath = "$basePath\mvps"
if (Test-Path("$mvpsHostUnzipFolderPath")) { Remove-Item $mvpsHostUnzipFolderPath -Recurse -Force }

$mvpsHostUrl = "http:https://winhelp2002.mvps.org/hosts.zip"

Write-Host "Downloading latest mvps host file from $mvpsHostUrl" 
Invoke-WebRequest $mvpsHostUrl -OutFile $mvpsHostZipFilePath
Unzip -zipfile $mvpsHostZipFilePath -outpath $mvpsHostUnzipFolderPath
Remove-Item $mvpsHostZipFilePath -Force

$mvpsFileContents = Get-Content -Path  "$mvpsHostUnzipFolderPath\hosts"
$mvpsLicenseFileContents = Get-Content -Path  "$mvpsHostUnzipFolderPath\license.txt"
Remove-Item $mvpsHostUnzipFolderPath -Recurse -Force

Write-Host $($mvpsLicenseFileContents -join "`r`n" | Out-String)

$message  = 'License'
$question = 'MVPS Host is protected by the above license. Are you sure you want to proceed?'

$choices = New-Object Collections.ObjectModel.Collection[Management.Automation.Host.ChoiceDescription]
$choices.Add((New-Object Management.Automation.Host.ChoiceDescription -ArgumentList '&Yes'))
$choices.Add((New-Object Management.Automation.Host.ChoiceDescription -ArgumentList '&No'))

$decision = $Host.UI.PromptForChoice($message, $question, $choices, 1)
if ($decision -eq 0) {
    UpdateHost -hostFilePath "$basePath\hosts" -mvpsFileContents $mvpsFileContents
} else {
    Write-Host 'Cancelled: Local Host file has NOT been updated'
}