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

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

function Enum-Users-Group($group)
{
    Write-Log ("`t`tGroup:" + $group.Name)
    foreach ($user in $group.Users)
    {
        Write-Log ("`t`t`t" + $user.LoginName)
    }
}

function Enum-Users-Web($web)
{
    Write-Log ("`tWeb:" + $web.Url)

    foreach ($g in $web.Groups)
    {
        Enum-Users-Group $g
    }

    foreach ($w in $web.Webs)
    {
        Enum-Users-Web $w
    }
}

function Enum-Users-Site-Col($site)
{
    Write-Log ("Site:" + $site.Url)
    Enum-Users-Web $site.RootWeb
    foreach ($w in $site.RootWeb.Webs)
    {
        Enum-Users-Web $w
    }
}

$wa = Get-SPWebApplication $url
foreach ($site in $wa.Sites)
{
    Enum-Users-Site-Col $site
}
#$site = Get-SPSite $url
#Enum-Users-Site-Col $site
#$web = Get-SPWeb $url
#Enum-Users-Web $web