assign more users to folder on powershell - windows

Question

everyone please help me, I need a command to assign permissions to a folder in the directory tree, conditional on the correct directory name to be assigned. I am trying to write a command line but when assigning a group or a user, it can be assigned but other users are removed, I want to not remove any users.
$mypath = "D:\KIEM TRA1"
$myacl = Get-Acl $mypath
$myaclentry = "EMC0\test.ktnb","readandexecute,write","Allow"
$myaccessrule = New-Object System.Security.AccessControl.FileSystemAccessRule($myaclentry)
$myacl.SetAccessRule($myaccessrule)
Get-ChildItem -Path "$mypath" -Recurse -Force |
Where-Object { $_.Name -eq 'A' -or $_.Name -eq 'B' } |
Set-Acl -AclObject $myacl -Verbose
I want to do it on a subdirectory and not remove the existing user

Answer 1

I guess what you need is to create a new access rule using 5 parameters, so you can handle inheritance and propagation too.
Try this (always on a set of test folders first of course..)
$mypath = "D:\KIEM TRA1"
$account = "EMC0\test.ktnb"
# see: https://learn.microsoft.com/en-us/dotnet/api/system.security.accesscontrol.filesystemrights
# https://learn.microsoft.com/en-us/dotnet/api/system.security.accesscontrol.inheritanceflags
# https://learn.microsoft.com/en-us/dotnet/api/system.security.accesscontrol.propagationflags
$rule = [System.Security.AccessControl.FileSystemAccessRule]::new($account, "Modify", "ContainerInherit,ObjectInherit", "None", "Allow")
# on older PowerShell versions use:
# $rule = New-Object System.Security.AccessControl.FileSystemAccessRule($account, "Modify", "ContainerInherit,ObjectInherit", "None", "Allow")
# get a list of folder FullNames of subfolders with name 'A' or 'B'
$folders = (Get-ChildItem -Path $mypath -Directory -Recurse | Where-Object { $_.Name -match '^[AB]$' }).FullName
foreach ($directory in $folders) {
# get the current ACL of the folder
$acl = Get-Acl -Path $directory
# add the new rule to the ACL
$acl.AddAccessRule($rule)
$acl | Set-Acl -Path $directory -Verbose
}
Note:
Instead of AddAccessRule(), you might prefer SetAccessRule().
AddAccessRule
This method will add this access rule to the ACL.
If a user has Modify permission and we use AddAccessRule() to create a new rule with Read permission the user will still also have Modify permissions.
SetAccessRule
This method removes any existing access an replaces that access with the specified rule.
If a user has Modify permission and a new rule is created using SetAccessRule() specifying Read permission, that user will now only have Read permission.