For example
% ls -al test.txt
-rw--r- 1 vastro vastro 121 May 21 00:46 test.txt
% chmod o-r test.txt
% ls -al test.txt
-rw---- 1 vastro vastro 121 May 21 00:46 test.txt
%
chmod o-r means dissallow others from reading this file. It is possible to string
together some parts of the command. For instance, to allow group
members read from and write to your file, do the following:
% chmod g+rw test.txt
% ls -al test.txt
-rw-rw-- 1 vastro vastro 121 May 21 00:46 test.txt
%
Exercise 12: Make all the files in the subdirectory data readable,writable and executable, only by you, and inaccessable to anybody else. Also, go to the ps directory and make all these files readable and executable by all, and writable for you.