param(
    [Parameter(Mandatory=$true)]
    [string]$url
)

function Write-Log($msg)
{
    Write-Host $msg -foregroundcolor green
    ($msg) | Out-File "log-delete-all-users.txt" -Append
}

$site = Get-SPSite $url
$confirmation = Read-Host "Are you sure you want to delete all users from " $site.Url " (y/n)"
if ($confirmation.ToLower() -ne "y") {
    return
}


$usersAll = @()
foreach ($u in $site.RootWeb.AllUsers)
{
	$usersAll += $u.LoginName
}
Write-Log ("Remove all users")
foreach ($u in $usersAll)
{
	Write-Log ("  " + $u)
	Remove-SPUser $u -Web $site.Url -Confirm:$false
}

$usersSite = @()
foreach ($u in $site.RootWeb.SiteUsers)
{
	$usersSite += $u.LoginName
}
Write-Log ("Remove site users")
foreach ($u in $usersSite)
{
	Write-Log ("  " + $u)
	Remove-SPUser $u -Web $site.Url -Confirm:$false
}