Question

I’m trying to find the next available computer name in out domain. Our computers use a naming format
departmentName001

departmentName003

departmentName004

…

departmentName999

I can find the existing computer accounts and add 1 but I can’t work out for to get it to start looking at 001, I’m aware of the use of "{0:d3}" -f but I’m not using it correctly. Can anyone help?

function GetComputerList($ComputerName)
{
$objSearcher = New-Object System.DirectoryServices.DirectorySearcher
$objSearcher.SearchRoot = “LDAP://dc=domain,dc=local”
$objSearcher.Filter = ("(&(objectCategory=computer)(name=$ComputerName))")
$colProplist = "name"
$objSearcher.PageSize = 1000
    foreach ($i in $colPropList){[void]$objSearcher.PropertiesToLoad.Add($i)}
$colResults = $objSearcher.FindAll()
foreach ($objResult in $colResults)
    {$objComputer = $objResult.Properties; $objComputer.name}
}


$HostName = Finance
$unit="{0:d3}" -f $_

$num = GetComputerList("$HostName*") | Foreach {[int]($_.Name)} | Sort-Object | Select-Object -Last 1 
$name = $HostName+($unit+($num+1))

Answer 1

Try this, it gets all computer with name starting with ‘departmentName’, strips all a-z characters, leaving just the numbers, converts the numbers to integers and sorting them to find the largest one:

$searcher = [ADSISearcher]'(&(objectCategory=computer)(name=departmentName*))'
$searcher.PageSize = 1000
$last = $searcher.FindAll() | Foreach-Object { [int]($_.Properties.name -replace '\D').Trim() } | Sort-Object | Select-Object -Last 1
$digitLength = "$last".Length
$NewComputerName = "{0}{1:D$digitLength}" -f 'departmentName',($last+1)
$NewComputerName 

EDIT:

# get next available number in a range of numbers. returns 5 for 1,2,3,4,6,7,9
$number = $searcher.FindAll() | Foreach-Object { [int]($_.Properties.name -replace '\D').Trim() } | Sort-Object    

for($i=0; $i -lt $number.length; $i++) {if( $number[$i+1]-$number[$i] -gt 1) {$number[$i]+1; break} }