Unfortunately, I'm not a linux user, so I'm not sure. You can see if google tells you how to use it?: https://www.google.com/search?rlz=1C1CHBF_enCA862CA862&ei=_ErKXfjjNeOl_QaF3YrYCA&q=how+to+use+chmod+in+linux&oq=how+to+use+chmod+in+linux&gs_l=psy-ab.3..0j0i22i30l9.45219.48652..48805...0.2..0.105.1753.21j1......0....1..gws-wiz.......0i71j0i273j0i67j0i7i30j0i13.HSvf9qlgHDw&ved=0ahUKEwj40eT1_-PlAhXjUt8KHYWuAosQ4dUDCAs&uact=5