Now that we have seen a little of the stream editor (sed), we can put this knowledge into practice. In Chapter 8, Introducing the Stream Editor, we familiarized ourselves with some of the capabilities of sed; however, this represented just a small amount of the power enclosed in the editor. In this chapter, we are going to exercise sed a little more and expose ourselves to some practical uses of the tool, especially when using our bash scripts.

In this journey, we will use sed to help us automate the creation of Apache name-based Virtual Hosts. The Apache hosts are practical users of the sed that we demonstrated but, more importantly, we will use sed to search for selected lines in the main configuration. We will then uncomment those lines and save them as a template. Having created the template, we will create new configurations from it. The concept...