Remove Name Notepad file if doesnt exist in AD through powershell - powershell

Question

$Users = GC "Desktop\Master.txt"
foreach ($user in $users) {
$userobj = $(try {Get-ADUser $user} catch {$Null})
If ($userobj -ne $Null) {
Write-Host "$User Exists"
} else {
Write-Host "$User Doesn't Exist"
}}
I am using this code to check if a user exists in AD. Later on this notepad file is processed to delete the users that are on the file. I was going to see if it was possible that I can remove the users off the list that don't exist. Is there a command to remove the line from the Notepad file that has the names on if the user doesn't exist in AD

Answer 1

Write a function to test just a single user:
function Test-ADUser {
param($Identity)
try {
$null = Get-ADUser #PSBoundParameters -ErrorAction Stop
# user must exist if we reached this point
return $true
}
catch [Microsoft.ActiveDirectory.Management.ADIdentityNotFoundException]{
return $false
}
}
Now you can use Where-Object to filter the list from the text file based on what the function determines:
# Read list from file, filter out usernames that don't exist
$filteredList = Get-Content "Desktop\Master.txt" |Where-Object { Test-ADUser -Identity $_ }
# Write filtered data back to disk
$filteredList |Set-Content "Desktop\Master.txt" -Force