Simple Unix Tutorial
====================

  In Unix data is organized in a hierarchical fashion using files and directories
(folders).  In the hierarchy, a forward slash '/' represents the root directory 
under which all system's files and directories reside.

  The following are commonly used Unix commands.  In the description below a %
character represents the Unix prompt.   


1. ls 
-----

   Definition:  list directory contents.   You can use the command with
   several options.  One option you might find useful is -l which provides 
   information like size, and last modification time.


   Example: (Assuming we have a file called data and a directory call Projects)
                (The file data has a size of 31 bytes and was modified on Feb 5 15:33)

% ls
Projects  data
% ls -l
total 6
drwxr-xr-x   3 bb131002 100         2048 Feb  5 15:54 Projects2
-rw-r--r--   1 bb131002 100           31 Feb  5 15:33 data
%


2. pwd
------

   Definition: prints the current working directory.  

   Example:

   % pwd
   /afs/wam.umd.edu/home/wam/b/b/bb131002/home/Test
   %

3. mkdir 
--------

   Definition: creates a directory.

   Example:
 
   % mkdir MyHomeworks

4. rmdir
--------

   Definition: removes a directory.  The directory must be empty.

   Example:

   % rmdir MyHomeworks

5. cd
-----

   Definition: changes the working directory.

   Example:

   % cd MyHomeworks         -> makes MyHomeworks the current directory
   % cd                     -> takes you back to your home directory
   % cd ..                  -> takes you to the directory above the current directory
   
6. rm
-----

   Definition: removes files or directories.

   Example:

   % rm data               -> removes file named data 
   % rm -f -r MyHomeworks  -> removes all the files/directories in the directory 
                              MyHomeworks

7. mv
-----

   Definition: moves files and directories and allows you to rename a file or directory.

   Example: (Assuming the file data2 does not exist and the directory Projects2 exist).

   % mv data data2         -> the file name has changed from data to data2 
   % mv data2 Projects2    -> the data2 file has been moved to Projects2
  

8. cp
-----

   Definition: copies files and directories. 

   Example: 

   % cp data data3        -> two files with exact contents

9. pico
-------

   Definition: simple text editor.  Follow the commands description at
               the bottom of the text editor for more information.

   Example:

   % pico data           -> creates a file named pico or opens it (if it already exist)


10. less 
--------

   Definition: allows you to browse through a text file.
 
   Example:

   % less data
   This is a file with some data.
   %

11. date
--------

   Definition: generates the current date and time.

   Example:

   % date
   Thu Feb  5 16:04:02 EST 2004
   %

12. passwd
---------

   Definition: allows you to change the account password.

   Example: 

   % passwd

13. man 
-------

   Definition: displays information about a command.

   Example: 

   % man less

14. logout
----------

   Definition: allows you to exit your account

   Example:

   % logout