#################################################################
# Script that allows to get all the users for all the Site Collections in a SharePoint Online Tenant
# Required Parameters:
#  -> $sUserName: User Name to connect to the SharePoint Admin Center.
#  -> $sMessage: Message to show in the user credentials prompt.
#  -> $sSPOAdminCenterUrl: SharePoint Admin Center Url

##################################################################

$host.Runspace.ThreadOptions = "ReuseThread"

#Definition of the function that gets all the site collections information in a SharePoint Online tenant
function Get-SPOUsersAllSiteCollections
{
param ($sUserName,$sMessage)
try
{
 Write-Host "----------------------------------------------------------------------------" -foregroundcolor Green
Write-Host "Getting the information for all the site colletions in the Office 365 tenant" -foregroundcolor Green
Write-Host "----------------------------------------------------------------------------" -foregroundcolor Green
$msolcred = get-credential -UserName $sUserName -Message $sMessage
Connect-SPOService -Url $sSPOAdminCenterUrl -Credential $msolcred
$spoSites=Get-SPOSite | Select *
foreach($spoSite in $spoSites)
{
Write-Host "Users for " $spoSite.Url -foregroundcolor Blue
Get-SPOUser -Site $spoSite.Url
Write-Host
}
 Write-Host "Getting users" -ForegroundColor Green
Get-SPOUser -Site "<SiteCollection URL>" | Out-File "C:UsersAdministratorDownloadsSharePoint OnlineUsers.txt" -Append;

 }
catch [System.Exception]
{
write-host -f red $_.Exception.ToString()
 }
}

#Connection to Office 365
$sUserName="<user account>"
$sMessage="SPO Credential Please"
$sSPOAdminCenterUrl="https://<Domain>-admin.sharepoint.com"
#Get-SPOUser -Site "https://<Domain>.sharepoint.com/" -LoginName "<user>"

Get-SPOUsersAllSiteCollections -sUserName $sUserName -sMessage $sMessage