After reading this chapter, you should now able to write a shell script that can be easy to maintain and modify by others. Now, you know how to use an existing shell script library in your own script by using the source command. You also got familiarity with fixing errors and bugs in a shell script by making use of the different debugging techniques. You should also know how to write a script by taking command line arguments and providing bash completion features for it.

In the next chapter, we will see how to view, change, create, and delete environment variables in order to meet the requirement of running our applications.