PowerShell 5.1可运行的网络信息脚本在7.5版本无输出

问题背景 #

以下PowerShell函数在Windows PowerShell 5.1中可正常返回网络信息，但在PowerShell 7.5中运行无任何输出：

function Read-NetworkInfo {
  Get-NetAdapter | Where-Object -Property Status -eq -Value 'Up'
}

function Get-NetworkInfo { 
  $nicList = Read-NetworkInfo 
  $ipList  = Get-NetIpAddress
  
  foreach ($nic in $nicList) {
      if ($nic.interfaceIndex -notin $ipList.InterfaceIndex) {
        continue
      }

    $macAddress   = ($nic).MacAddress
    $prefixLength = (Get-NetIPAddress `
                       -InterfaceAlias $nic.Name `
                       -AddressFamily IPv4
                     ).PrefixLength
    $ipAddress    = (Get-NetIPAddress `
                      -InterfaceIndex $nic.ifIndex
                     ).IPv4Address 
   
    $ipAddress    = [string]$ipAddress
    $prefixLength = [int]$prefixLength

    $firstOctet   = 255 # constant , first octet of net mask will always be 255
    $secondOctet  = [int](([version] $ipAddress).Minor)
    $thirdOctet   = [int](([version] $ipAddress).Build)
    $fourthOctet  = [int](([version] $ipAddress).Revision)

    
    if ($prefixLength -le 16) {
      $difference  = $prefixLength - 8
      $secondOctet = 256 - ([Math]:: Pow(2, $prefixLength - (2 * $difference)))
      $thirdOctet  = 0 
      $fourthOctet = 0

    }
    elseif ($prefixLength -le 24) {
      $difference  = $prefixLength - 12
      $secondOctet = 255
      $thirdOctet  = 256 - ([Math]:: Pow(2, $prefixLength - (2 * $difference)))
      $fourthOctet = 0
    
    }
    else {
      $difference  = $prefixLength - 16
      $secondOctet = 255
      $thirdOctet  = 255
      $fourthOctet = 256 - ([Math]:: Pow(2, $prefixLength - (2 * $difference)))
      
    }

    [string]$netmask = '0.0.0.0' 
    $octets = $firstOctet, $secondOctet, $thirdOctet, $fourthOctet
    $netmask = $octets -join ('.')
    
    $netObj = @{
      InterfaceAlias       = $nic.InterfaceAlias
      InterfaceIndex       = $nic.InterfaceIndex
      InterfaceDescription = $nic.InterfaceDescription
      NetProfileName       = $nic.NetProfileName
      IPv4Address          = $nic.IPv4Address
      IPv6DefaultGateway   = $nic.IPv6DefaultGateway
      IPv4DefaultGateway   = $nic.IPv4DefaultGateway
      DNSServer            = $nic.DNSServer
      MacAddress           = $macAddress
      NetMask              = $netmask
    }

    $netJSON = $netObj | ConvertTo-Json
    Write-Host $netJSON

    if ($nicList.length -gt 1) {
      Write-Host $separator 
    }

    $lineBreak

    Add-Content -Path "$HOME\Downloads\serverscript.json" -Value $netJSON

  }#end foreach nic
  
}

问题原因 #

1. 属性获取差异：PowerShell 7中Get-NetAdapter默认不返回IPv4Address、DNSServer、NetProfileName等属性，这些属性在PS 5.1中是隐式关联其他模块数据返回的，PS7中需要显式获取。
2. 空值处理错误：当$ipAddress为空时，[version]$ipAddress会抛出异常，直接中断循环。
3. 集合长度判断错误：$nicList.length仅对数组有效，当$nicList是单个对象时该属性不存在，导致后续逻辑失效。
4. 未定义变量：$separator和$lineBreak未定义，会输出空值干扰执行流程。
5. 子网掩码计算逻辑漏洞：原计算逻辑依赖IP地址的版本解析，且数学运算存在逻辑错误，在PS7中可能返回异常值。

修复后的函数代码 #

function Get-NetworkInfo {
    # 获取所有状态为Up的网卡及关联的IP配置
    $nicConfigs = Get-NetAdapter -Status Up | Get-NetIPConfiguration
    
    # 定义分隔符和换行符
    $separator = "------------------------"
    $lineBreak = "`n"

    foreach ($config in $nicConfigs) {
        # 获取IPv4地址信息，跳过无IPv4的网卡
        $ipv4Addr = $config.IPv4Address | Where-Object { $null -ne $_.IPAddress }
        if (-not $ipv4Addr) {
            continue
        }

        # 计算子网掩码（更可靠的方法）
        $prefixLength = $ipv4Addr.PrefixLength
        $netmask = [System.Net.IPAddress]::Parse(([System.Net.IPAddress]::NetworkToHostOrder(-1 -shl (32 - $prefixLength)) -band 0xFFFFFFFF)).ToString()

        # 构建输出对象
        $netObj = @{
            InterfaceAlias       = $config.InterfaceAlias
            InterfaceIndex       = $config.InterfaceIndex
            InterfaceDescription = $config.InterfaceDescription
            NetProfileName       = $config.NetProfile.Name
            IPv4Address          = $ipv4Addr.IPAddress
            IPv4DefaultGateway   = $config.IPv4DefaultGateway.NextHop
            IPv6DefaultGateway   = $config.IPv6DefaultGateway.NextHop
            DNSServer            = $config.DNSServer.ServerAddresses -join ', '
            MacAddress           = $config.MacAddress
            NetMask              = $netmask
        }

        # 转换为JSON并输出
        $netJSON = $netObj | ConvertTo-Json
        Write-Host $netJSON

        # 多网卡时输出分隔符
        if ($nicConfigs.Count -gt 1) {
            Write-Host $separator
        }
        Write-Host $lineBreak

        # 写入文件
        Add-Content -Path "$HOME\Downloads\serverscript.json" -Value $netJSON
    }
}

关键改动说明 #

• 改用Get-NetIPConfiguration：直接关联网卡与IP配置，确保在PS7中能获取到完整的IP、网关、DNS等属性。
• 空值检查：跳过无IPv4地址的网卡，避免空值转换异常。
• 子网掩码计算优化：使用.NET类库方法直接根据前缀长度生成子网掩码，逻辑更可靠，避免手动计算错误。
• 集合计数修正：用$nicConfigs.Count替代$nicList.length，兼容单个对象和数组的情况。
• 定义缺失变量：明确$separator和$lineBreak的值，避免输出空内容。
• 属性映射修正：调整NetProfileName、DNSServer等属性的获取路径，适配PS7中的对象结构。

内容的提问来源于stack exchange，提问作者mimi m