Administrer les droits des dossiers partagés SPO via powershell

Hi ViriisXP,

thanks for your question, I don't speak French so I will try to help you in English.

To achieve the permission settings you described for your SharePoint Online (SPO) folders and subfolders using PowerShell (if I translated it properly), you can use the SharePoint Online Management Shell.

Before running the script, make sure you have installed the SharePoint Online Management Shell and connected to your SharePoint Online environment.

You can download SharePoint Online Management Shell here: 
Download SharePoint Online Management Shell from Official Microsoft Download Center

Here's a PowerShell script that sets the permissions for each folder and its subfolders as you mentioned:

# Connect to SharePoint Online
Connect-SPOService -Url https://yourtenantname-admin.sharepoint.com

# Set the root URL of your document library
$rootUrl = "https://yourtenantname.sharepoint.com/sites/sitename/Shared Documents"

# Function to set folder permissions
function Set-FolderPermissions {
param (
[Microsoft.SharePoint.Client.Folder]$folder,
[Microsoft.SharePoint.Client.RoleType]$permissionLevel
)
$ctx = $folder.Context
$folder.ListItemAllFields.BreakRoleInheritance($true, $false)
$ctx.Load($folder.ListItemAllFields.RoleAssignments.Add($folder.ParentList.ParentWeb.SiteGroups.GetByName("YourReadOnlyGroup"), $permissionLevel))
$folder.Context.ExecuteQuery()
}

# Function to recursively set permissions for folders and subfolders
function Set-PermissionsRecursively {
param (
[Microsoft.SharePoint.Client.Folder]$folder
)
$ctx = $folder.Context
$ctx.Load($folder.Folders)
$ctx.Load($folder.ListItemAllFields)
$ctx.ExecuteQuery()

# Set permission for the current folder
Set-FolderPermissions -folder $folder -permissionLevel [Microsoft.SharePoint.Client.RoleType]::Read

# Recursively set permissions for subfolders
foreach ($subfolder in $folder.Folders) {
Set-PermissionsRecursively -folder $subfolder
}
}

# Main script
$ctx = Get-SPOContext

# Get the root folder
$rootFolder = $ctx.Web.GetFolderByServerRelativeUrl($rootUrl)
$ctx.Load($rootFolder)
$ctx.ExecuteQuery()

# Set permissions recursively for each folder and its subfolders
Set-PermissionsRecursively -folder $rootFolder

You will need to modify the script by replacing `https://yourtenantname.sharepoint.com/sites/sitename/Shared Documents` with the actual URL of your document library. Also, replace `"YourReadOnlyGroup"` with the name of the security group that should have read-only access.