=====unix Keyword 2=====
command expansion

====Definition====
Definition (in your own words) of the chosen keyword.

====References====
List any sites, books, or sources utilized when researching information on this topic. (Remove any filler text).

  * Reference 1
  * Reference 2
  * Reference 3



=====unix Keyword 2 Phase 2=====
shell

====Definition====
A shell acts as the interface between a user and an operating system in which the user can launch other programs or access directories.  There are two types of shells, command line or graphical.  A windows operating system uses the graphical interface Windows Explorer to allow users to access programs and view files, where as a Unix systems tend to use the command line interfaces wherein text is typed at the command line prompt in order to launch programs and enter commands to view directories.  

====References====
List any sites, books, or sources utilized when researching information on this topic. (Remove any filler text).

  * [[http://en.wikipedia.org/wiki/Shell_(computing)]]
  * __Harley Hahn's Guide to Unix and Linux__ by Harley Hahn
 


====Demonstration====
Demonstration of the indicated keyword.

If you wish to aid your definition with a code sample, you can do so by using a wiki **code** block, an example follows:

<code c>
/*
 * Sample code block
 */
#include <stdio.h>

int main()
{
    return(0);
}
</code>

Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:

<cli>
lab46:~$ cd src
lab46:~/src$ gcc -o hello hello.c
lab46:~/src$ ./hello
Hello, World!
lab46:~/src$ 
</cli>