NC State Computing Center

Unix File and Directory Structure

The Unix system gives you directories, subdirectories, and files within your directories and/or subdirectories. Properly organizing your directories, subdirectories and files is the key to being able to locate and use information efficiently.

Information is stored in either program or data files; program files contain instructions that the operating system uses to perform tasks while data files store your information. You group similar files into specific directories.

Your Home File Space

Your home directory is identified by your userid. Your home directory is also referenced by the tilde (~) symbol, and this symbol can be used in commands when you need to refer back to your home directory.

Facutly and staff accounts come with 10 megabytes (MB) of disk space; students (graduate and undergraduate) receive 8 MB. Beginning in the fall of 1997, all accounts will go up to 20 MB). Faculty, staff, and graduate students can acquire more disk space by renting lockers from Computing Services. For more information on lockers, contact a consultant (515-3035, help@ncsu.edu) or, using the browser of your choice, open a URL to: 

  
Locker_Policy.html

Aside from our user home file space, unix has a root directory, represented as a forward slash mark (/).

Various subdirectories branch from the root directory, including "bin" and "afs"; the "afs directory" links to the user's directories where your home file space is kept. It also links you to other AFS Unity cells.

Note that when you do a directory listing, there are two files that always appear in the listing as "." and ".."; these are called dot files and they represent your current (.) and parent directories (..). The current directory is the directory that you are in--the parent directory is one level above the current directory. It may be helpful to think of the parent directory as "owning" the current ("child") directory.

Paths and Path Names

When you are referring to where a certain file or application is located, you call it a path. The path specifies the exact location of the file or application.

To find out what your current or working directory is, use the pwd command.The pwd command means to print working directory to the screen so that you can see its complete path. An example of how this works is shown below: 

	unity% pwd  
	/afs/unity.ncsu.edu/users/n/noell
	unity%

The /afs/unity.ncsu.edu/users/n/noell is the complete path of your home directory, even though the prompt only says unity%.

Getting Help

There are numerous ways in which to receive assistance when using the Eos/Unity system. Consultants are available to answer your questions and they can be reached at:

Another way users can get help is to search the consultants' frequently asked questions (FAQ) database that can be accessed through the World Wide Web. If you have a question, there is a possibility that it has already been asked and you can find the answer by searching this help database. To access this database, enter the following URL from your Web browser: 
http://www.ncsu.edu/help
In addition to the HELP database on the World Wide Web, there is also a tutor command. This can be entered from your unity prompt, and will start up the Netscape Web browser and take you to the help page containing the Computing Services tutorials. If you are at a Unix workstation, you can use your middle mouse button to click on the Help option. This will take you to the Help page as discussed above.

Finally, there is also a command on the Eos/Unity system called man, which stands for manual. This command, followed by a keyword, will bring up the standard manual page entry for that command. The format of the command is man keyword, replacing "keyword" with the keyword on which you need help.

For example, to ask for help on the ls (list files) command, you would enter, from your unity prompt: man ls.

If you do not know the command, enter man -k topic replacing "topic" with the topic your command deals with (e.g., man -k list).

The man pages appear one screen at a time. When reading man pages, to view the next screen, hit your space bar; to quit, hit"q".

Go on to next section, Editors in unity/unix

Return to Table of Contents