Private (Personal) Directories (Unix Power Tools, 3rd Edition)

7.5. Private (Personal) Directories

You might want to create a private directory for your personal files: love letters, financial data, complaints about your boss, off-color jokes, or whatever you want to keep there. While you can set any directory you own to be private, having one in your home directory is convenient to organize all of your private directories together. For simplicity, you can just name it private; giving it a less obvious name, however, can make it more difficult for prying eyes to discover.

Once you've created a private directory, you should set its file access mode ( Section 50.2) to 700; this means that you're the only person allowed to read, write, or even list the files that are in the directory. Here's how:

% mkdir private
% chmod 700 private

On any Unix system, anyone who knows the root password can become superuser (Section 49.9) and read any files he wants. So a private personal directory doesn't give you complete protection by any means -- especially on systems where most users know the root password. If you really need security, you can always encrypt your files.

--ML and DJPH