Powershell Try Catch and retry?

Question

I have this script

#Change hostname
[void][System.Reflection.Assembly]::LoadWithPartialName('Microsoft.VisualBasic') 
Write-Host "Change hostname " -NoNewLine
$ComputerName = [Microsoft.VisualBasic.Interaction]::InputBox('Insert the desired computername:', 'Change hostname') 
Write-Host "- DONE" -ForegroundColor DarkGreen -BackgroundColor green -NoNewline
Write-Host " hostname = $ComputerName "
Rename-Computer -NewName $ComputerName

when the computer name gets spaces, it fails cause a hostname cant have spaces. Can i block the form to have any spaces or does anyone knows how to get back to the inputbox when a error has been created for a re-try

Answer 1

do {
    $ComputerName = [Microsoft.VisualBasic.Interaction]::InputBox('Insert the desired computername:','Change hostname')
} while ($ComputerName -match "\s")

using a do{}while() loop and checking the Input doesn't have any whitespace should resolve your issue, this will re-prompt until a valid hostname is input, if you want to check for any errors at all:

do{
    $Failed = $false
    Try{
        $ComputerName = [Microsoft.VisualBasic.Interaction]::InputBox('Insert the desired computername:', 'Change hostname') 
        Write-Host "- DONE" -ForegroundColor DarkGreen -BackgroundColor green -NoNewline
        Write-Host " hostname = $ComputerName "
        Rename-Computer -NewName $ComputerName -ErrorAction Stop
    } catch { $Failed = $true }
} while ($Failed)