.. _shellscript:

===================
Shell script basics
===================

| A shell is the layer between you and the unix operating system, and provides easy access to unix commands. If you are new to shell programming, please read `How do I write a shell script? <http://www.freeos.com/guides/lsst/ch01sec09.html>`_.  
| Popular basic text editors include 'gedit' (graphical interface), and 'nano' (curses-based interface). More advanced editors include 'vi' and 'emacs'.


**Example**

    Below is an example of a simple shell script that prints the date, and then sleeps 20 seconds.

    #. Start a text editor::

        $ nano

    #. Enter the following text, and save as 'simple.sh':

        |  #!/bin/sh
        |  date
        |  sleep 20
    
    #. Make the script executable::
    
        $ chmod a+x simple.sh
    
    #. Run the command at the shell prompt::
    
        $ ./simple.sh