Chapter 4. Creating and Calling Subroutines

This chapter shows how to create and call subroutines in a script.

The topics covered in this chapter are as follows:

• Show some simple subroutines.
• Show more advanced routines.
• Mention return codes again and how they work in scripts.

In the previous chapters we have seen mostly simple scripts that were not very complicated. Scripts can actually do a whole lot more which we are about to see.

First, let's start with a selection of simple but powerful scripts. These are mainly shown to give the reader an idea of just what can be done quickly with a script.