Learning the Unix Operating System, 5th Edition

Chapter 3. Using Your Unix Account

Once you log in, you can use the many facilities that Unix provides. As an authorized system user, you have an account that gives you:

• A place in the Unix filesystem where you can store your files.

• A username that identifies you, lets you control access to your files, and is an address for your email.

• An environment you can customize.

The Unix Filesystem

A file is the unit of storage in Unix, as in most other systems. A file can hold anything: text (a report you’re writing, a to-do list), a program, digitally encoded pictures or sound, and so on. All of those are just sequences of raw data until they’re interpreted by the right program.

In Unix, files are organized into directories. A directory is actually a special kind of file where the system stores information about other files. You can think of a directory as a place, so that files are said to be contained in directories and you are said to work inside a directory. (If you’ve used a Macintosh or Microsoft Windows computer, a Unix directory is similar to a folder.)

This section introduces the Unix filesystem. Later sections in this chapter show how you can look in files and protect them. Chapter 4 has more information.

Your Home Directory

When you log in to Unix, you’re placed in a directory called your home directory. This directory, a unique place in the Unix filesystem, contains the files you use almost every time you log in. In your home directory, you can make your own files. ...