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 (16 chapters)
15
Index

Automating Virtual Host creation

After having created the template, we can now use this to create Virtual Host configurations. In the simplest terms, we need to replace the dummy-host.example.com URL with sales.example.com or marketing.example.com URL. Of course we have to also create the DocumentRoot directory, the directory where the web pages will be and also add some basic content. When we use a script to run through the process nothing will be forgotten and the edits will be accurate every time. The basics of the script will be as follows:

#!/bin/bash
WEBDIR=/www/docs
CONFDIR=/etc/httpd/conf.d
TEMPLATE=$HOME/template.txt
[ -d $CONFDIR ] || mkdir -p $CONFDIR
sed s/dummy-host.example.com/$1/ $TEMPLATE > $CONFDIR/$1.conf
mkdir -p $WEBDIR/$1
echo "New site for $1" > $WEBDIR/$1/index.html

If we ignore the shebang as the first line, we should know this by now. We can start our explanation in line 2 of the script:

Line

Meaning

WEBDIR=/www/docs/

We initialize the WEDIR variable...