Backup-ADUserMembership.ps1

<#

      Author: I.C.A. Strachan
      Version:
      Version History:

      Purpose: Backup User group membership to file on a per user base

#>
[CmdletBinding()]
param(
   [string]
   $csvFile='users.csv',
   
   [string]
   $exportFolder = '.\export\dsa\UserMemberOf\backup\',

   [Microsoft.PowerShell.Commands.FileSystemCmdletProviderEncoding]
   $Encoding = 'UTF8',

   $Delimiter = "`t"
)

#region Verify folder exists
$LogDate = get-date -uformat '%d-%m-%Y'

if(!(test-path "$exportFolder\$logDate")) {
    $null = New-Item "$exportFolder\$logDate" -ItemType Directory -Force
}
#endregion 

#region Define Hashtables for splatting
$csvParam = @{
    Path = ".\source\csv\$csvFile"
    Delimiter =  $Delimiter
    Encoding = $Encoding
}

$exportParam = @{
   Delimiter = $Delimiter
   Encoding = $Encoding
   NoTypeInformation =  $true
}
#endregion
 
#region Main  
Import-Csv @csvParam | 
ForEach-Object{
    Get-ADUser -Identity $_.SamAccountName -Properties MemberOf | 
    Select-Object -ExpandProperty Memberof | 
    Get-ADGroup | 
    Select-Object SamAccountName, DistinguishedName |
    Export-Csv @exportParam -Path "$exportFolder\$logDate\$($_.SamAccountName).csv" 
}
#endregion