File System Layout
Most of the information on this page comes from Dr. Bill Miller III at A. T. Still University.
As you get started, you should have an idea of how the files are organized on your computer.
Root Directory
If you change to the top-most directory (cd /), and list (ls)
all the files there. This is called the root directory. All of the
computer’s files are located in subdirectories of this folder.
Most Unix computers are designed so that only administrators,
also called ‘root’, can make changes in this directory.
You do not need to know what is within most of these folders
since they pertain to the operating system and are not something
you can change without being root.
Bin Directories
As you get more familiar with Unix, you will notice that one of the
most important folders are called bin directories.
These directories contain programs and can be executed to perform
certain tasks. For example, if you cd to the root bin directory
(cd /bin) and ls you will notice there are a bunch of
different programs in this directory.
They are all executable (any file with an asterisk (*) at the end
of the name is designated as executable), which means you can run
the program. Most of the programs here are unimportant for our
immediate purposes, but if you look closely, this folder contains
several programs that you are already familiar with. For example,
when you listed all the files in this directory, you typed ls.
Guess where the ‘ls’ program is located? In the /bin/ directory!
So every time you type ls you are actually executing the ls
program in this folder, which lists all the files in your current
directory. Other programs in this directory you already know
include mkdir, rm, mv, and vi. This manual will actually introduce
you to several more programs within this directory later.
There are actually multiple bin directories on computers that
include different programs that you already know and will learn
about through this manual:
/bin//usr/bin//usr/local/bin/sbin/
Home Directory
Within the root directory, there is a subdirectory called home that
contains folders for all users allowed to access the computer.
When you open a brand new Terminal window, you will find yourself in
your home directory (/home/$USER/). So if you change directories
immediately, you should do so knowing that you begin in your home
directory. You can also access the files in any other user’s home
directory by changing to their directory in the /home/ folder.
You can change directories to the home directory using the following
command: cd /home/username
You can also just type cd.
Typing cd without anything following it will automatically take you
to your home directory. Another equivalent command would be
cd ~/
which will also change directories to your home directory. Another
interesting note is that you can easily get to other user’s home
directories using the tilde.