Book Image

Mastering Linux Shell Scripting

By : Andrew Mallett
Book Image

Mastering Linux Shell Scripting

By: Andrew Mallett

Overview of this book

Shell scripting is a quick method to prototype a complex application or a problem by automating tasks when working on Linux-based systems. Using both simple one-line commands and command sequences complex problems can be solved with ease, from text processing to backing up sysadmin tools. In this book, you’ll discover everything you need to know to master shell scripting and make informed choices about the elements you employ. Get to grips with the fundamentals of creating and running a script in normal mode, and in debug mode. Learn about various conditional statements' code snippets, and realize the power of repetition and loops in your shell script. Implement functions and edit files using the Stream Editor, script in Perl, program in Python – as well as complete coverage of other scripting languages to ensure you can choose the best tool for your project.
Table of Contents (21 chapters)
Mastering Linux Shell Scripting
About the Author
About the Reviewer

Apache name-based Virtual Hosts

For the demonstration, we will be working with the httpd.conf file from an Apache 2.2 HTTPD Server taken from a CentOS 6.6 host. To be perfectly honest, we are far more interested in the configuration file, as Red Hat or CentOS supply it, than the actual configuration changes that we will make. Our purpose is to learn how we can extract data from the system-supplied file and create a template from it. We can apply this to Apache configuration files or any other text data file. It is the methodology, we are not looking at the actual result.

To have some understanding of what we are trying to do, we must first look at the /etc/httpd/conf/httpd.conf file that is shipped with Enterprise Linux 6, that is, CentOS, Red Hat Enterprise Linux, or Scientific Linux. The following screenshot shows the virtual host section of the file that we are interested in:

Looking at these lines, we can see that they are commented and this is all a part of a monolithic httpd.conf. While...