4.5 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. Call it anything you want, but private is a good name. [I usually give my private directories names that don't imply they're private. -JP ] Once you've created a private directory, you should set its file access mode (22.2) 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 and read any files he or she wants. So a private personal directory doesn't give you complete protection by any means - especially since, on many UNIX systems, most users know the root password. But it does keep prying eyes away. If you really need security, you can always encrypt (22.17) your files.