1. File system and command shell 
A command shell is a keyboard based interface to the operating system. Commands are typed in at the command line; they perform operations and may print out results. Commands may take options (switches) to modify their behaviour. You can find out information about commands by using the man command e.g. man ls to look up the manual page for the ls list command: alternatively you can use google  On Linux most things are represented as files in the file system including programs, commands, settings, devices, data, applications etc. 
a) Explore the operating system file system using the following commands: ls, cd, pwd and more. Get used to moving around the file system using these commands. 
b) Find your operating systems file which represents the kernel, where is it? Which version is it? And how big is it? 
c) Use ps and top to find out which processes are running, which processes takes most CPU time? Which takes most memory? What are the different states in which a process can be? 

2. I/O Redirection and Pipes 
a) The (>) operator can be used to redirect the output of a command (what would normally be printed on the screen) into a file. Redirect the output of the ls and ps commands into files. 
b) The output of one command can be redirected into another command using the pipe operator (|). Thus the (screen) output of the first command becomes the (keyboard) input of the second command. Use the wc and ps commands to count how many processes that are running. Show the composite command. 

3. Finding Files 
a) How can the find command be used to find all files whose names contain the word “kernel”? 

4. Editing Files 
a) Learn how to use the nano editor to edit a simple text file. For example edit a file to contain your groups names and student numbers. (There are lots of online guides to using nano e.g. http://www.raspberrypi-spy.co.uk/2013/11/quick-guide-to-nano-text-editor-on-the-raspberry-pi/ ) 

Once you have completed these practical exercises you should individually demonstrate your understanding and competency to your tutor during tutorial. You need your tutor to be satisfied that you have this new practical knowledge and skill in order to pass this module. 

Further Investigation Questions 
Please answer the following questions. 
1. Linux history 
a) List some of the key developments to the Linux operating system over its lifetime and explain why they are important. 

2. Embedded OS 
a) What is an embedded operating system? 
b) List three places where you might find an embedded operating system. 

3. Open source software 
a) Why might an open source operating system be preferable to a closed source one? 
b) How do companies like RedHat make money from ‘free’ software? 

4. References 
Provide a list references to all material you have used.