Automate the removal of the DNS Root of a computer name

PowerShell Help
1

I am trying to figure out how I can remove the DNS Root of a computer so I can plug that into the Get-ADComputer cmdlet.

What I am doing is taking a list of IP addresses and resolving those to computer names like so:

$ComputerNames = @(Get-Content 'C:\IPAddressList.txt' | ForEach-Object{ 
([System.Net.Dns]::GetHostEntry($_)).Hostname.ToUpper()})

Then when I call on the $ComputerNames variable it gives me the computer names along with the DNS Root at the end, like so:

SalesComputer102.my.domain.com

How can I go about removing the “.my.domain.com” DNS Root so I can just use the computer name for Get-ADComputer?

Get-ADComputer errors if I try to use ‘SalesComputer102.my.domain.com’

Thanks

2

Assuming $computername has the entire string,

$justthecomputer = $computername -replace “.mydomain.com”,“”

Would do that.

3

Thanks Don, I already figured this out by doing the following:

$FQDNComputers = 'SalesComputer102.my.domain.com'
$DNSRoot = (Get-ADDomain).DNSRoot 
Foreach ($Computer in $FQDNComputers)
{           
    $Computer -Replace(".$DNSRoot","")
}