Function to take a given txt or csv file and compare it against your Active Directory.

Compare-ADFromFile.ps1

# Function to take a given txt or csv file and compare it against Active Directory
# Requires the Active Directory PowerShell Module
# EXAMPLE: Compare-ADFromFile -File .\affected_user_accounts.txt
function Compare-ADFromFile {
    # Path to the file of names to compare against AD
    [CmdletBinding()]
    param (
        [Parameter(Position=0, Mandatory, ValueFromPipeline)]
        [System.String[]]
        $File
    )
    # Get Names
    $names = Get-Content -Path $File
    # Make sure we have the AD Powershell Module
    Import-Module ActiveDirectory
    # Iterate through all usernames
    $output = foreach ($name in $names) {
        # If the user does exist in AD, gather all properties. Tweak the Properties parameter to your needs.
        try {
            Get-ADUser $name -Properties * -ErrorAction SilentlyContinue | Select-Object * | Sort-Object -Property SamAccountName 
        } # If the user does not exist in AD, just give a simple message in the console
        catch [Microsoft.ActiveDirectory.Management.ADIdentityNotFoundException] {
            Write-Host "$name does not appear in your Active Directory"
        } # If all else fails...
        catch {
            Write-Host "Something else went wrong while searching for $name"
        }
    # Export to CSV
    $output | Export-Csv -Path ".\Compare-ADFromFile_output.csv"
    }
}