This section on shell basics is probably the most essential of the course. If you cannot use these basic features such as command substitution, you cannot effectively write shell scripts. Because of this, there are a lot of notes to give you two perspectives on the topic/ As always, read the book first. 

1. notes on the book - module 2
   
2. variables and arithmetic
3. command substitution
4. quoting
5. examples

Copyright 2016 Greg Boyd - All Rights Reserved.