ValidateLength Powershell

Question

This is my first script so don\'t beat me up to bad!

I\'m working on a script that creates a network directory & AD group based on user input. The following is w

Answer 1

As @briantist already pointed out, validation functions were made for a different purpose (parameter validation). You have a different scenario, since you want to keep prompting the user until a valid value is entered. Validation functions just don't work well in this scenario for a number of reasons:

• they throw an error instead of returning a boolean value, which is fine for a function call, but not for validating a value.
• they don't repeat, so you need additional code anyway,
• their parameters can't be variables.

I would probably put the input/validation loop in a function and use numeric comparisons instead of checking the length of a string, since you're asking the user to input numbers anyway.

function Get-Number {
  [CmdletBinding()]
  Param(
    [Parameter(Mandatory=$true)]
    [string]$Prompt,
    [Parameter(Mandatory=$false)]
    [int]$Min = 0,
    [Parameter(Mandatory=$false)]
    [int]$Max = 9999
  )

  # prevent infinite loop due to impossible condition
  if ($Min -gt $Max) { throw 'Min cannot be greater than max.' }

  $ErrorActionPreference = 'SilentlyContinue'
  do {
    $num = Read-Host -Prompt $Prompt
    $valid = $Min -le $num -and $Max -ge $num
    if (-not $valid) { Write-Host "Invalid value: $num" }
  } until ($valid)

  return [int]$num
}

$Division = Get-Number -Prompt 'Please enter the TWO digit division number' -Min 10 -Max 99
$Matter   = Get-Number -Prompt 'Please enter the FOUR digit matter number' -Min 1000 -Max 9999
$Client   = Get-Number -Prompt 'Please enter the FOUR digit client number' -Min 1000 -Max 9999