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.