TSAD

0.0.1

Public/Get-ADDomainName.ps1

function Get-ADDomainName {
    [CmdletBinding(SupportsShouldProcess)]
    Param (
    [Parameter(Mandatory,ValueFromPipeline)]
    [object[]]$ADObject
    )

    begin {
    # (?i) enables case insensitivity for rest of expression
    # \w matches a word, {1,} match one or more word, ? lazily
    # \b matches a word boundary (any non word char)
    $RegEx = '(?i)DC=\w{1,}?\b'
    }

    process {
    $DN  = $ADObject.DistinguishedName
    $Sam = $ADObject.SamAccountName
    Write-Verbose "Finding domain for $Sam..."
    $DN  = (
        [RegEx]::Matches($DN, $RegEx) |
          ForEach-Object {
          $_.Value
          }
    ) -Join ','

    if ($DNToDomain[$DN]) {
        Write-Verbose "$Sam is in $($DNToDomain[$DN])."
        return $DNToDomain[$DN]
    } else {
        Write-Verbose "$Sam can't be found in any domain!"
    }
    }
}