CSOM PowerShell function to check if the a SharePoint Online site exits? It accepts credential and Url and return true or false.

$siteUrl = 'https://spo.sharepoint.com/sites/teamsite'

$credential = Get-Credential;

function CheckSiteExists($credential,$siteUrl){

 Add-Type -Path "C:\Program Files\SharePoint Online Management Shell\Microsoft.Online.SharePoint.PowerShell\Microsoft.SharePoint.Client.dll" 

 Add-Type -Path "C:\Program Files\SharePoint Online Management Shell\Microsoft.Online.SharePoint.PowerShell\Microsoft.SharePoint.Client.Runtime.dll" 

     $ctx = New-Object Microsoft.SharePoint.Client.ClientContext($siteUrl)

     $Creds = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($credential.UserName,$credential.Password);

     [System.Net.WebRequest]::DefaultWebProxy.Credentials = $Creds # needed for default gateway.

     $ctx.Credentials = $Creds;

     $web = $ctx.Web

      $ctx.Load($web)

      try{

            $ctx.ExecuteQuery()         

            return $true

         }

         catch{           

            return $false

        

         }  

        

}

#Calling the function: CheckSiteExits  $credentials $siteUrl

Update Logo using CSOM for SharePoint Online.

How to update the Update Logo using CSOM for SharePoint Online / 0365

The following PowerShell will update SharePoint Online logo for Site Collection /sites/sctest

function UpdateLogo(){

Add-Type -Path "C:\Program Files\SharePoint Online Management Shell\Microsoft.Online.SharePoint.PowerShell\Microsoft.SharePoint.Client.dll"

Add-Type -Path "C:\Program Files\SharePoint Online Management Shell\Microsoft.Online.SharePoint.PowerShell\Microsoft.SharePoint.Client.Runtime.dll"

try{

$siteUrl = "https://spdemo.sharepoint.com/sites/sctest"

$credential = Get-Credential

$Creds = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($credential.UserName,$credential.Password);

$ctx = New-Object Microsoft.SharePoint.Client.ClientContext($siteUrl)

[System.Net.WebRequest]::DefaultWebProxy.Credentials = $Creds # needed for default gateway.

$ctx.Credentials = $Creds;

$ctx.Web.SiteLogoUrl = "/SiteAssets/banner.jpg";

$ctx.Web.Update();

$ctx.ExecuteQuery();

$ctx.Dispose();

Set-OutPut "Logo Updated.." "NO ERROR"

$OutMsg = $OutMsg + "QH Logo Updated." + "`r`n"

Write-host $OutMsg

}

catch{

$Outmsg = $OutMsg + "`r`n"

$Outmsg = $OutMsg + "Error in function: UpdateLogo" + "`r`n"

$OutMsg = $OutMsg + "Line : $($_.InvocationInfo.ScriptLineNumber)" + "`r`n"

$OutMsg = $OutMsg + "$($_.Exception)" + "`r`n"

$OutMsg = $OutMsg + "$($_.Exception.Message)" + "`r`n"

Write-host $OutMsg

}

}