nslookup++ / How to Resolve a List of Hostnames to a List of IPs...

...with access to the DOS command prompt commands and the bare minimum set of PowerShell cmdlets.

Copy and paste the script below into a text editor and save as say nslookup++.ps1, and run in PowerShell as .\nslookup++.ps1.

Example image of it in use is below (using public website addresses since cannot share internal hostnames on this blog.)

Image: Example of nslookup++ in action

The Script

[Boolean]$Repeat = $TRUE

While($Repeat){

  Write-Host "nslookup++: RESOLVES LIST OF HOSTNAMES TO IP"

  Write-Host "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"

  Write-Host "Enter list of hostnames (can paste a list)"

  Write-Host "  and press ENTER on empty line to continue (no input terminates program):"

  [System.Array]$Hosts = @()

  [Boolean]$do = $TRUE

 

  While($do){

    $ReadIn = Read-Host

    If($ReadIn -eq ""){$do = $FALSE}

    else{$Hosts += $ReadIn}

  }

 

  [System.Array]$HostsOut = @()

  $Hosts | Foreach{

    If($_ -eq "NONE"){$HostsOut += "NO CHECK"}

    else{

      [System.Array]$nslookup = (nslookup $_)

      [Int32]$TempCount = 0

      [String]$Result = ""

      Foreach($line in $nslookup){

        $TempCount++

        If($line.StartsWith("Name")){

          $Result = $nslookup[$TempCount].Split(" ")[2]

        }

      }

      If(!$Result){$HostsOut += "DNF"}

      else{$HostsOut += $Result}

    }

  }

 

  $HostsOut | Foreach{Write-Host $_}

  If($Hosts.count -eq 0){$Repeat = $FALSE}

  else{PAUSE}

}