Powershell apply a function to each member of a list

Question

I have a list of permissions for a folder, I want to test if each IdentityReference in this list exist in another list consisting of IdentityReferences, if it matches do nothing, else remove permission for this IdentityReference.

Bare it mind, the above is only to describe what I am aiming to do, I already have a working code, but the problem is it is 10 lines, I want to do it all in minimum number of lines.

$perm = $acl.Access | select IdentityReference, FileSystemRights | where {$_.IdentityReference -notin @("BUILTINAdministrators", "NT AUTHORITYSYSTEM")}

Now I have to apply a user defined function to each IdentityReference in the $perm, is this possible to do all in one line?

Answer 1

try this

$perm = $acl.Access | select IdentityReference, FileSystemRights | where {$_.IdentityReference -notin @("BUILTINAdministrators", "NT AUTHORITYSYSTEM")}
$perm | %{yourfunction $_.IdentityReference}

or on the same line

$acl.Access | select IdentityReference, FileSystemRights | where {$_.IdentityReference -notin @("BUILTINAdministrators", "NT AUTHORITYSYSTEM")} | %{yourfunction $_.IdentityReference}