file-acl

file-acl is a built-in function in `C source code'.

(file-acl FILENAME)

Return ACL entries of file named FILENAME.
The entries are returned in a format suitable for use in `set-file-acl'
but is otherwise undocumented and subject to change.
Return nil if file does not exist or is not accessible, or if Emacs
was unable to determine the ACL entries.